9 BASELINE Marine Ecological RESOURCES

9.1 Introduction

The waters and coastal areas of Southwest Lantau including the Soko Island group, which are located away from the major population centres of Hong Kong, have long been the subject of interest by academics, government and green groups, and there is a broad consensus that this general area is an area of conservation interest including from a marine ecological perspective. A variety of studies have investigated the marine ecology of Southwest Lantau waters , and as a result of these and in particular the AFCD-commissioned feasibility study ([1]), both the coastal waters off Southwest Lantau Island and the waters around the Soko Island Group have been proposed for designation as Marine Parks.

This Annex presents the findings of marine ecological studies of the South Soko Island and the surrounding Study Area. Marine ecological habitats and resources have been identified and the ecological value of the Study Area evaluated. The assessment has been based on a review of the currently available literature, as well as detailed field surveys to provide the most up-to-date information on existing conditions. Rationales for the surveys are presented, followed by the methodologies employed, results obtained and a discussion of the results and comparison with other similar studies. The findings of this Annex form the basis of establishing the ecological importance of the different marine habitats on and around South Soko Island, which in turn form part of the ecological assessment conducted in the EIA study.

9.1.1 Ecological Study Area

The Study Area for the ecological assessments is based on the footprint of the proposed LNG terminal on South Soko and the broad alignment corridor for the submarine pipeline connection to the Black Point Power Station, submarine cable and water main connection to Shek Pik, as well as the areas identified for water quality impact assessment.

The South Soko LNG terminal is proposed to be located in the centre of the island, as presented in the engineering layout (Figure 9.1). Due to the existing platform of the former detention camp, the majority of land needed for the terminal already exists; however, small areas of reclamation will be required to the west and east of the platform. Reclamation on the eastern side of the platform will be required for the construction of a sheltered anchorage and to the west for the third storage tank. A jetty to serve LNG carriers would be located on the southern coast of South Soko Island. To allow navigation for LNG carriers, an approach channel and turning circle is required and this would be located in waters to the south of South Soko Island. The LNG terminal would also require a cooled water intake and water outflow pipe. The proposed location of the water intake is to the east of the island, while the outflow would discharge below the jetty on the southern coast.

The South Soko LNG terminal will connect to the Black Point Power Station via a submarine pipeline. The proposed alignment for the submarine pipeline corridor is presented in Figure 9.2. The route has been selected in order to maintain separation from the existing Sha Chau and Lung Kwu Chau Marine Park and the potential Marine Park on the West of Lantau Island.

Power and water supplies required for the routine operation of the LNG terminal will be provided by a new submarine cable and water main connecting South Soko Island to South Lantau, via Shek Pik (Figure 9.2). The routes for the power cable and water main are nearly parallel to each other and has the shortest length avoided most of the major elements including the Country Park, Green Belt, existing sand deposit area locations of high dolphin and porpoise sighting density.

The Study Area for the marine ecology baseline has incorporated the proposed alignment corridor for the submarine pipeline connection to the Black Point Power Station and the reclamation areas.

9.1.2 Structure of the Annex

Following this introductory section, the remainder of this Marine Ecological Baseline Annex is arranged as follows:

Section 9.2 – Presents a summary of the legislation for the protection of species and habitats of terrestrial and marine ecological importance and in Hong Kong.

Section 9. 3 – Presents the baseline marine ecological conditions at the South Soko Island and the proposed submarine pipeline corridor.

Section 9. 4 – Evaluates the ecological importance of the habitats and species of the Study Area.

Section 9.5 – Summarizes the baseline marine ecological conditions of the Study Area.

9.2 Legislative Requirements and Evaluation Criteria

9.2.1 Introduction

This section summarizes all legislative requirements and evaluation criteria for the protection of species and habitats of marine ecological importance.

9.2.2 Legislative Requirements and Evaluation Criteria

Legislative requirements and evaluation criteria relevant to the study are as follows:

1. Marine Parks Ordinance (Cap 476);

2. Wild Animals Protection Ordinance (Cap 170);

3. Protection of Endangered Species of Animals and Plants Ordinance (Cap 586);

4. Town Planning Ordinance (Cap 131);

5. Hong Kong Planning Standards and Guidelines Chapter 10 (HKPSG);

6. The Technical Memorandum on Environmental Impact Assessment Process under the Environmental Impact Assessment Ordinance (EIAOTM);

7. United Nations Convention on Biodiversity (1992);

8. Convention on Wetlands of International Importance Especially as Waterfowl Habitat (the Ramsar Convention); and,

9. PRC Regulations and Guidelines.

10. City University of Hong Kong (2001). Agreement No. CE 62/98, Consultancy Study on Fisheries and Marine Ecological Criteria for Impact Assessment, AFCD, Final Report July 2001.

9.2.3 Marine Parks Ordinance (Cap 476)

The Marine Parks Ordinance provides for the designation, control and management of marine parks and marine reserves. It also stipulates the Director of Agriculture and Fisheries as the Country and Marine Parks Authority which is advised by the Country and Marine Parks Board. The Marine Parks and Marine Reserves Regulation was enacted in July 1996 to provide for the prohibition and control certain activities in marine parks or marine reserves.

9.2.4 Wild Animals Protection Ordinance (Cap 170)

Under the Wild Animals Protection Ordinance (Cap 170), designated wild animals are protected from being hunted, whilst their nests and eggs are protected from destruction and removal. All birds and most mammals including all cetaceans are protected under this Ordinance, as well as certain reptiles (including all sea turtles), amphibians and invertebrates. The Second Schedule of the Ordinance that lists all the animals protected was last revised in June 1997.

9.2.5 Protection of Endangered Species of Animals and Plants Ordinance (Cap 586)

The Protection of Endangered Species of Animals and Plants Ordinance (Cap 586) was enacted to align Hong Kong’s control regime with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). With effect from 1 July 2006, it replaces the Animals and Plants (Protection of Endangered Species) Ordinance (Cap 187). The purpose of the Protection of Endangered Species of Animals and Plants Ordinance is to restrict the import and export of species listed in CITES Appendices so as to protect wildlife from overexploitation or extinction. The Ordinance is primarily related to controlling trade in threatened and endangered species and restricting the local possession of them. Certain types of corals are CITES listed, including Blue coral (Heliopora coerulea), Organ pipe corals (family Tubiporidae), Black corals (order Antipatharia), Stony coral (order Scleractinia), Fire corals (family Milleporidae) and Lace corals (family Stylasteridae). The import, export and possession of listed species, no matter dead or living, is restricted.

9.2.6 Town Planning Ordinance (Cap 131)

The recently amended Town Planning Ordinance (Cap 131) provides for the designation of areas such as “Coastal Protection Areas”, “Sites of Special Scientific Interest (SSSIs)”, “Green Belt” and "Conservation Area” to promote conservation or protection or protect significant habitat.

9.2.7 Hong Kong Planning Standards and Guidelines Chapter 10

Chapter 10 of the HKPSG covers planning considerations relevant to conservation. This chapter details the principles of conservation, the conservation of natural landscape and habitats, historic buildings, archaeological sites and other antiquities. It also addresses the issue of enforcement. The appendices list the legislation and administrative controls for conservation, other conservation related measures in Hong Kong, and Government departments involved in conservation.

9.2.8 Technical Memorandum on Environmental Impact Assessment Process under the Environmental Impact Assessment Ordinance

Annex 16 of the EIAOTM sets out the general approach and methodology for assessment of ecological impacts arising from a project or proposal, to allow a complete and objective identification, prediction and evaluation of the potential ecological impacts. Annex 8 recommends the criteria that can be used for evaluating ecological impacts.

9.2.9 Other Relevant Legislation

The Peoples’ Republic of China (PRC) is a Contracting Party to the United Nations Convention on Biological Diversity of 1992. The Convention requires signatories to make active efforts to protect and manage their biodiversity resources. The Government of the Hong Kong Special Administrative Region has stated that it will be “committed to meeting the environmental objectives” of the Convention (PELB 1996).

The Convention on Wetlands of International Importance Especially as Waterfowl Habitat (the Ramsar Convention) applies in the HKSAR. The Convention requires parties to conserve and make wise use of wetland areas, particularly those supporting waterfowl populations. Article 1 of the Convention defines wetlands as "areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters." The Mai Po/Inner Deep Bay wetland was declared a Wetland of International Importance (“Ramsar site”) under the Convention in 1995.

The PRC in 1988 ratified the Wild Animal Protection Law of the PRC, which lays down basic principles for protecting wild animals. The Law prohibits killing of protected animals, controls hunting, and protects the habitats of wild animals, both protected and non-protected. The Law also provides for the creation of lists of animals protected at the state level, under Class I and Class II. There are 96 animal species in Class I and 156 in Class II. Class I provides a higher level of protection for animals considered to be more threatened.

9.3 Marine Ecological Resources - Background

9.3.1 Introduction

This section describes the baseline conditions of the marine ecological resources at South Soko Island and the Study Area from existing information. Baseline conditions have been assessed based on a review of the findings of relevant studies and the collation of available information regarding the marine ecological resources of this part of Hong Kong.

Based on this review, an evaluation of the information collected was conducted to identify any gaps that need to be filled in order to conduct an assessment of ecological importance of the marine habitats. Where information gaps were identified, or where certain habitats or species were considered to warrant further attention, field surveys have been conducted.

9.3.2 Site History

The South Soko Island is an outlying island located in the southwest waters of the Hong Kong Special Administrative Region (SAR), approximately 4 km from Lantau Island.

In terms of water quality, the island experiences estuarine conditions owing its position at the eastern side of the Pearl River estuary. The influence of the Pearl River is most pronounced in the summer wet season months and is characterised by elevated turbidity and reduced salinity. During the dry season, the influence of the Pearl River on waters close to the island subsides. During the dry season, the island experiences more oceanic conditions, particularly during the northeast monsoon. During a flood tide the waters surrounding the island move rapidly from the southeast passing both to the north and south of the island and through the channel between North and South Soko Islands. On the ebb tide, flows are reversed. Throughout the tidal cycle currents are generally strongest to the north of the island and weakest to the southeast.

Most recently, the island was the location of a Detention Centre operated by the Hong Kong Government. As part of the construction of this facility a relatively large portion of the coastline in Sai Wan, a sheltered bay on the west coast, and Tung Wan, an exposed bay on the east coast, was reclaimed. Prior to this development, however, the shoreline remained natural and mainly consisted of rocks, boulders and sandy beaches.

Two areas designated and administered by the Civil Engineering and Development Department (CEDD) of the Hong Kong Government for dredging and disposal operations fringe the South Soko Island (Figure 9.2). The Sokos Marine Borrow Area (MBA) is located to the south of Lantau and extends westwards from the Sokos Island to the boundary of Hong Kong waters. The MBA originally contained shallow sand resources that were dredged prior to 1993, primarily using cutter suction dredging techniques. Some minor volumes of sand have been extracted since 1993, but there are currently no plans for further extensive sand removal or backfilling by CEDD. Approximately 5 km east of South Soko Island is the South Cheung Chau Disposal Area. Occupying an area of approximately 7.5 km by 2.5 km, this is the largest mud disposal area in Hong Kong. The area was first gazetted for “General Purpose” disposal in 1981 and more recently has been used as an open water disposal site for uncontaminated dredged material. In 1993 alone, approximately 80 Mm3 of grab and trailer dredged material was disposed at the site, however, due to mounding at the site, allowed disposal quantities have since been reduced.

9.3.3 Literature Review

Based on the literature review the following habitats and/or organisms of ecological interest have been identified at South Soko:

· Hard Bottom Habitats; and

- Intertidal Hard Bottom Habitats

- Subtidal Hard Bottom Habitats

· Soft Bottom Habitats;

- Intertidal Soft Bottom Habitats

- Subtidal Soft Bottom Habitats

· Epifaunal Assemblages

· Infaunal Assemblages

· Marine Mammals;

The existing conditions of each of the above habitats/organisms based on available literature are presented in the following sections.

9.3.4 Hard Bottom Habitats

Approximately 80% of Hong Kong's complex shorelines and many islands are composed of rocky outcrops. Shores in Hong Kong display characteristic zonation patterns, with a progression of different species along the vertical gradient from terrestrial to marine environments.

Intertidal Hard Bottom Habitats

The intertidal habitat of South Soko is mainly semi-exposed to exposed rocky shore, with limited boulder shore scattered along the coastline. Artificial rocky coastline fringes the bays on both the western and eastern sides of the island. At Shek Pik, the landing site for the submarine cable and watermain is a sandy beach with intertidal rocky shore in the vicinity. The intertidal habitat of Black Point where the Gas Receiving Station to be located is mainly artificial sloping seawall.

Previous surveys conducted as part of the focussed survey of the South West Lantau marine habitats, recorded assemblages that were considered to be typical of the habitat type in Hong Kong ([2]). The majority of species recorded were considered to be common in Hong Kong.

For this EIA Study, it was considered appropriate to conduct intertidal surveys on South Soko Island, Black Point and Shek Pik in order to fill data gaps and provide up-to-date data on the ecological value of the habitats. No surveys were considered necessary on the intertidal habitats in vicinity of the proposed submarine pipeline alignment as habitats are relatively distant and therefore, impacts are anticipated to be negligible.

Subtidal Hard Bottom Habitats

Coral reefs support a range of species providing shelter, feeding, spawning and nursery areas, resulting in the large and diverse community for which they are renowned. The coral reef system has been shown to be sensitive to pollution and impacts from development can cause the ecosystem to collapse, resulting in widespread mortality of coral and the numerous associated organisms. Natural fluctuations in water quality can also regulate coral communities.

The Agriculture, Fisheries and Conservation Department report that there are over 80 species of corals recorded in Hong Kong waters ([3]). It appears that coral distribution in Hong Kong is primarily controlled by hydrodynamic conditions as Hong Kong’s western waters are influenced by the Pearl River Estuary, which lowers salinities. The greatest diversity and abundances of corals are generally found in the north eastern waters of Hong Kong due to the optimal environmental conditions for settlement, growth and survival found in these waters. The western and southern waters of Hong Kong are influenced by the Pearl River Estuary, greatly reducing salinities, increasing turbidity and therefore reducing light penetration. Ahermatypic octocorals, including soft and black corals, which unlike the hermatypic hard corals do not require light for zooxanthellae photosynthesis, are more widely distributed and often occur at greater depths.

A number of studies of the subtidal hard bottom habitats in vicinity to the proposed South Soko LNG terminal have been conducted. In 1997, as part of the Coastal Ecology Studies, commissioned by the Civil Engineering Department, qualitative dive surveys of corals were conducted at the Soko Islands. The findings of these surveys characterised the islands as having low abundance and moderate diversity of hard coral species. Faviid coral, which are common hard coral species in Hong Kong, were identified as the most abundant species, however, cover was low ([4]). Other species recorded were soft coral Dendronephthya sp., sponges, sea whips and coralline algae.

In 1998, a study on Shek Kwu Chau, in the vicinity of the Soko Islands identified coral habitats that were of low ecological value ([5]) . Few sporadic and isolated hard coral communities were recorded, with considerable sedimentation on the majority of hard surface substratum ([6]).

Recently, as part of a study of the marine habitats of South West Lantau, dive surveys were conducted on the large granitic slabs and boulders of the Soko Island shoreline ([7]). The waters of the area were noted as being highly turbid with high sedimentation rates, which would likely limit coral growth. The surveys found sparsely scattered coral colonies of encrusting faviids, interspersed with a few soft corals of the genus Dendronephthya. Most colonies were small with relative sizes varying little amongst most colonies. In comparison to other sites in Hong Kong, the coral communities were considered to be of low ecological value.

Surveys of subtidal hard bottom habitat in the vicinity of the proposed submarine pipeline, submarine cable and watermain are limited. However, it should be noted that as discussed above, the general trend for coral communities in Hong Kong is one of increasing abundance and diversity from west to east with the greatest diversity and abundance generally found in the eastern waters of Hong Kong. As a result of the turbid conditions along the west and southwest of Lantau, light penetration is greatly reduced in the water column. Due to the requirements for coral growth, the cumulative effect of these conditions results in suboptimal conditions for coral recruitment and survival. Coral communities of any significance are therefore not expected to occur on the shores in vicinity of the proposed pipeline, cable and watermain route.

9.3.5 Soft Bottom Habitats

Intertidal Soft Bottom Habitats

As part of a recent territory wide study of Hong Kong soft shores, surveys were recently conducted at Pak Tso Wan ([8]). Although this site had a relatively low diversity of polychaetes, crustaceans, molluscs, a moderate diversity (31 species) of chordates (i.e. fish fry) was recorded. Of the 42 soft shores studied across Hong Kong, Pak Tso Wan (labelled Tai A Chau) was ranked 24th in terms of conservation value. Together with 15 other soft shores in Hong Kong, this site was assigned into the “important” conservation category. By comparison, sites categorised as having higher conservation importance were 12 shores classed as “very important” and 1 classed as “extremely important”. Sites with less conservation importance than Pak Tso Wan were 9 sites categorised as “can be conserved” and 2 sites regarded as having “low priority”.

Two species of Horseshoe Crabs (Tachypleus tridentatus and Carcinoscorpius rotundicauda) have been recorded in Hong Kong waters. As numbers of these marine organisms are known to have drastically declined in recent years, recommendations for their conservation have been made ([9]). In Hong Kong, the intertidal sand/sandy-mud flats at Shui Hau and San Tau, on Lantau Island, the mud flats at Pak Nai, in Deep Bay have recorded juveniles of both species, whereas, adult horseshoe crabs are occasionally fished from the subtidal mud along the northwest coast to the Lantau Island, including Tai O, Yi O, Sham Wat Wan, Sha Lo Wan and Tung Chung Bay (Figure 6.3). All of the horseshoe crab breeding grounds are located far away from the LNG terminal, proposed gas pipeline, submarine cable and watermain.

Subtidal Soft Bottom Habitats

Epifaunal Assemblages

Subtidal soft bottom habitats, as well as supporting infaunal species, commonly support macro-benthic epifauna. These organisms are generally greater than 1mm in size and live either on or within the surface sediments.

Data on epifaunal assemblages in Hong Kong are primarily available from studies conducted on fisheries resources. Due to the nature of the Hong Kong fishery and the typical subtidal substratum in Hong Kong being soft bottom habitat, data collected from demersal trawling operations provide the largest amount of information on epifaunal assemblages.

Information on the epifaunal assemblages in proximity to the proposed LNG terminal on South Soko Island and along the Preliminary submarine pipeline corridor has been taken from a review of the largest such study in Hong Kong, namely the Agriculture, Fisheries and Conservation Department commissioned study on Fisheries Resources and Fishing Operations in Hong Kong ([10]).

Surveys undertaken as part of this study indicates that that the highest biomasses recorded in the waters around the Soko Islands were of Squillidae (mantis shrimp). Other families such as Penaeidae (prawn) were recorded in relatively high abundance. In general, biomass was relatively high, however, species abundance and diversity was low in comparison to other sites in Hong Kong.

A more recent survey on epifaunal assemblages in and around the Soko Islands and Shek Pik has been conducted in 1999 as part of a focussed survey on the South West of Lantau ([11]). As part of this study, trawls were conducted on the soft bottom habitats to characterise the epifauna of the areas.

The majority of organisms collected in both wet and dry seasons were either mantis shrimps or prawns, with the highest species diversity from small fish or crabs. These species are common in Hong Kong and are found in the majority of Hong Kong’s waters. Abundance was low in comparison to other areas of Hong Kong. It was stated that the most notable pattern in the epifaunal assemblages was the low biomass of the individuals recorded. Most fish were considered to be juveniles or immature adults. The absence of adult fish was concluded by the HKIE study to be as a result of fishing pressure in the area.

A review of 10-years of data on fisheries resources collected from demersal trawls conducted as part of the ongoing marine monitoring of contaminated mud disposal at the East of Sha Chau Contaminated Mud Pits provides data on epifaunal assemblages to the west of Lantau, in the vicinity of Tai O and the Lung Kwu Chau and Sha Chau Marine Park ([12]). As these areas are in relatively close proximity to the proposed pipeline route, these data can be considered to be representative of the epifaunal assemblages in this area.

These data indicate that epifaunal assemblages are dominated by gastropods (eg Turritella terebra), crabs and mantis shrimps. Abundance and species composition was considered to be relatively low in comparison to other areas in Hong Kong. No species that were considered to be rare in Hong Kong were recorded.

Based on the above, the epifaunal assemblages in the proposed study area are considered to be of low abundance, diversity and biomass in comparison to other areas of Hong Kong and have, thus, not been identified of conservation interest.

Infaunal Assemblages

Soft sediments consisting of silt, clay and sand dominate the seabed of Hong Kong. These soft bottom habitats support infaunal assemblages that act as a food source for Hong Kong’s inshore commercial fisheries resources. Due to the general dominance of these habitats in Hong Kong’s subtidal marine environment, extensive studies have been conducted on infaunal assemblages throughout Hong Kong. However, the majority of these studies have focussed on providing a “snapshot” of infaunal assemblages either within or in close proximity to a proposed area for development, or as part of a specific monitoring programme. In order to provide an indication of the potential ecological value of the infaunal assemblages at the LNG terminal location as well as along the preliminary pipeline corridor, it is considered useful to review studies that have investigated infaunal assemblages in Hong Kong on a wide scale. Where considered useful, studies of infaunal assemblages at specific locations have also been included in the review.

Both the waters around the proposed terminal site as well as the waters of the preliminary submarine pipeline corridor were surveyed as part of a Hong Kong wide study conducted in 1976, however, the findings of this study are considered to be no longer applicable due to the extensive development in both Hong Kong and the Pearl River Estuary that was since occurred. This is supported by the findings of a recent, second, Hong Kong wide study on infaunal assemblages ([13]).

A comparison of the results of the 1976 study and the 2001 study found that changes in benthic communities, particularly species composition had occurred. This was reported as being primarily as a result of a wider distribution and increase in abundance of pollution tolerant species such as Prionospio spp and Mediomastus spp.

The Seabed Ecology Studies were a Hong Kong wide study commissioned by the former Civil Engineering Department of the Hong Kong Government examining infaunal assemblages at areas of either previous or ongoing marine sand dredging and mud disposal. The results provided a comparison of benthic abundance, biomass and taxonomic richness at eight areas in Hong Kong, one of which was located in the waters surrounding the Soko Islands (Table 9.1Table 9.1) ([14]). The findings of the study concluded that the sites in the southern waters, where the proposed South Soko LNG terminal site is located, were found to have infaunal assemblages of higher abundance, biomass and taxonomic richness when compared to sites in the eastern waters of Hong Kong, however, similar if not lower when compared to sites of increased habitat heterogeneity such as the Tathong Channel. It was speculated that the comparatively high values at the Soko MBA were as a result of the exhausted sand borrow area in the vicinity of the sampling sites. The heterogeneity of habitat provided by this substratum would likely have increased the infaunal assemblages in the area. It is worth noting, however, that the average weight per individual at the Soko MBA site was relatively low, suggesting the abundance of opportunistic, low biomass colonising species (polychaete worms).

Table 9.1 Comparison of Data on Infaunal Assemblages at Eight Sites in Hong Kong Collected in the Seabed Ecology Studies, 1996 – 1998 ([15]).

Comparative Note	Study Site
	East Sha Chau	Basalt Island	East of Ninepins	Soko Islands	South Cheung Chau	Eastern Waters	Tathong Channel	South Lamma
Abundance (no. m-2)	468	240	294	2,187	2,080	352	3,130	1,674
Rank Abundance	5	8	7	2	3	6	1	4
Biomass (g m-2)	7.5	6.1	12.8	35.7	47.2	32.9	35.7	30.6
Rank Biomass	7	8	6	2	1	4	2	5
Diversity (families grab-1)	7	13	12	21	15	12	22	16
Rank Diversity	8	5	6	2	4	6	1	3
Average weight per individual (total g m-2/ total no. m-2)	0.0016	0.026	0.044	0.017	0.023	0.094	0.012	0.019
Rank weight per individual	7	3	2	6	4	1	8	5
Average Rank	6.75	6	5.25	3	3	4.25	3	4.25

Note: Shaded cells indicate highest ranking.

The findings that opportunistic colonisers make up the majority of the infaunal assemblages in the soft bottom habitat in the vicinity of the Soko Islands was supported by the Hong Kong wide benthic surveys conducted in 2001 ([16]). Due to the extensive survey effort undertaken as part of this study, the results provide up-to-date information on the infaunal assemblages both within close proximity to the proposed LNG terminal and along the proposed submarine pipeline corridor (Table 9.2Table 9.2).

Table 9.2 Comparison of Data on Infaunal Assemblages at four areas in vicinity of the proposed South Soko LNG Terminal and the Submarine Pipeline, Cable and Watermain Routes, Data Collected in the Study on Marine Benthic Communities in Hong Kong, 2000 – 2001 ([17]).

Comparative Note	Lung Kwu Chau and Sha Chau		West Lantau Island		Soko Islands		Shek Pik
	Wet Season	Dry Season	Wet Season	Dry Season	Wet Season	Dry Season	Wet Season	Dry Season
Abundance (no. m-2)	143	406	426	1,436	811	1,245	810	432
Biomass (g m-2)	14.52	7.98	4.08	37.62	46.99	55.47	118	36.66
Diversity (species 0.5 m-1)	23	56	34	38	64	70	69	59

The findings of the CityU study were that the stations at the Soko Islands had higher species, individuals and biomass in comparison to the other stations along the proposed pipeline, cable and watermain routes, ie Shek Pik, West Lantau and the Lung Kwu Chau and Sha Chau Marine Park. It was suggested that, as put forward in the Seabed Ecology Studies, the higher values for infaunal assemblage parameters were as a result of the recovery of benthos following sand dredging operations at the Soko Marine Borrow Area. This was supported by the dominance of opportunistic species such as Prionospio spp and Paraprionospio spp at the Soko Island survey stations.

Based on the findings of comparatively high abundance, biomass and diversity of the infaunal assemblages in the soft bottom habitats in the waters surrounding the Soko Islands and, to a lesser degree, along the proposed pipeline, cable and watermain routes, it is considered appropriate to conduct benthic surveys to provide up-to-date data on such assemblages.

9.3.6 Marine Mammals

A total of 16 (and possibly up to 18) species of marine mammals, or cetaceans, have been recorded in Hong Kong waters ([18]). The Indo-Pacific Humpback Dolphin, Sousa chinensis, and the Finless Porpoise, Neophocaena phocaenoides, are the only two species of marine mammals regularly sighted in Hong Kong waters ([19]) ([20]).

Studies on the distribution, abundance, habitat use, and life history of humpback dolphins within Hong Kong have been undertaken since 1995 ([21])([22])([23]). The results of these ongoing studies indicated in 2004 that approximately 1,300 individual dolphins are estimated to utilise the waters of the Pearl River Estuary. Of these individual dolphins, approximately 360 are thought to include waters within Hong Kong as part of their range.

Historically, marine mammal data have been presented in terms of sightings ([24]). Recent analysis adopted in the marine mammals monitoring study ([25]) has allowed data to be standardised to reflect numbers of sightings in terms of survey effort. Such data are considered to be closer to a direct indication of abundance and habitat usage than raw observational data. In order to utilise the most up-to-date data, yet still allow comparison with previous studies to be made, both types of data will be discussed.

Abundance of humpback dolphins in Hong Kong waters is highest in the north and west Lantau areas (Figure 9.3). North Lantau and West Lantau are considered to be the major habitats for humpback dolphins in Hong Kong waters where individuals of humpback dolphins have been consistently sighted throughout the year.

Humpback dolphins exhibit a seasonal shifting in abundance and density and thus a seasonal variation of abundance in different locations. The variation is thought to be due to the increased input of freshwater from the discharge of the Pearl River Estuary and the subsequent movements of estuarine prey species ([26]) ([27]) ([28]) .

Recently published information indicates that the abundance of dolphins in Hong Kong ranges from 91 in spring to 207 in autumn ([29]). Present estimates for the Pearl River Estuary population range from 678 in summer to 1,171 in winter ([30]).

Historical data on the utilisation of the waters around the proposed LNG terminal on South Soko Island and the waters of the preliminary submarine pipeline have been reported ([31]) ([32]). From October 1995 to November 2004, there were sightings of humpback dolphins in the South Lantau areas ([33]). Humpback dolphins appeared to be more concentrated on the western side of South Lantau and around Soko Islands ([34]). The long-term sightings database revealed that their sightings are low in comparison to other areas, particularly during the spring months.

In contrast to humpback dolphins, studies on the finless porpoise indicated that the majority of sightings in the long-term dataset have been recorded in the southern and eastern waters of Hong Kong (Figure 9.4). While sightings of finless porpoise have been recorded in the waters surrounding the proposed LNG terminal at South Soko, their recorded distribution in Hong Kong western waters does not extend as far as the waters off West Lantau, North Lantau or Deep Bay ([35]). Therefore, in contrast to humpback dolphins, no sightings of finless porpoise have been recorded within the West Lantau waters of the submarine pipeline route connecting the LNG terminal to the Black Point Power Station.

As with humpback dolphins, distribution of finless porpoise in Hong Kong waters varies seasonally (Figure 9.4). The highest numbers of sightings of finless porpoise have been in spring and winter throughout Hong Kong waters, as well as those waters surrounding the Soko Islands. Lowest numbers of sightings were in summer and autumn ([36]). It is suggested that a large proportion of the local finless porpoise population moves out of Hong Kong waters in the summer and autumn months, potentially as a result of the influx of freshwater in those months, and hence more estuarine conditions. In general, there appears to be a seasonal shift in sightings from the west in winter and spring to the east in summer and autumn in Hong Kong waters. Many of the finless porpoise sighted were calves and juveniles. Recent monitoring data have indicated higher sightings of Finless Porpoise in South Lantau than Lamma but lower than in the waters around the Po Toi Island group ([37]) .

The recent studies on marine mammals in Hong Kong have attempted to conduct quantitative analysis of habitat use ([38]). On the whole, raw sightings records plotted on maps are generally not a good guide to ascertaining marine mammal densities because different areas are not given the same amount of survey effort. To give a more meaningful picture of where dolphins occur, corrected sighting densities have been calculated in terms of number of on-effort sightings per km2, with the survey area mapped using a 1 km by 1 km grid. These data are presented as Sightings Per Survey Effort (SPSE) values. The average SPSE per grid in West and Northwestern Lantau (most of the grids has SPSE value >20) is comparatively higher than the average SPSE per grid in other areas of Hong Kong waters with the values mostly ranged from 1 – 9.

Based on the results of the information available from the long term sighting data on marine mammals in the waters of Hong Kong, it appears that sightings of both of Hong Kong’s resident cetacean species, Sousa chinensis and Neophocaena phocaenoides have been recorded within the waters surrounding the proposed LNG terminal on South Soko Island. Sightings of Sousa chinensis have also been recorded in the waters of the preliminary submarine pipeline corridor.

In order to provide up-to-date and detailed comprehensive baseline information to supplement information from the literature, a programme of marine mammal surveys was undertaken for this EIA Study. A dual survey approach was adopted so that both land-based surveys on South Soko and vessel-based surveys were undertaken. The timing of these different survey types was not concurrent (Table 9.3Table 9.3). It is important to note that the data generated by these two different survey approaches was intended to serve different purposes. Overall, the survey programme was specifically designed to focus on gathering information on marine mammal utilisation of waters around the Soko Islands as well as covering regions across Hong Kong western waters. For instance, the position of line transects along which the survey vessel travelled were tailored to give higher resolution of survey effort around the Soko Islands. As such, the vessel-based surveys results provide the scientific basis for calculating all quantitative estimates of dolphin abundance for this EIA Study.

Land-based surveys, on the other hand, were undertaken with the aim of closely focusing on marine mammal utilisation of nearshore waters in the vicinity of the proposed LNG terminal location. The results yielded from the land-based survey are qualitative in nature and cannot be used for quantitative determination of marine mammal abundance. Land-based surveys, nevertheless, serve a useful purpose by providing supplementary information for the assessment. While the vessel-based surveys provide ample data to conduct the assessment, when taken together the vessel-based and land-based provide a highly detailed database of marine mammal information for this assessment.

9.3.7 Baseline Marine Ecological Surveys

The literature review of the marine ecological habitats and resources of the waters within, and in close proximity to, the proposed LNG terminal at South Soko Island and the waters of the preliminary submarine pipeline corridor has provided an indication of their ecological importance. However, in order to provide up-to-date information on the marine ecological baseline conditions the following field surveys were considered necessary (Table 9.3Table 9.3).

Table 9.3 The Marine Ecology Baseline Surveys (Location refer to Figures 9.5& 9.6)

Survey Type	Methodology	Date
Intertidal Assemblages at South Soko	Rocky shore/ artificial shoreline Quantitative (belt transects at 9 locations) survey, three 100 m belt transects (at high, mid and low intertidal zones) for each location, covered both wet and dry seasons. Sandy Shore Quantitative (line transects at two locations) survey, 50 x 50 x 50cm core at three points (high, mid and low intertidal zones) along each of the transects, covered both wet and dry seasons.	8 & 9 March, 28 & 29 July and 14 September 2004, 17 & 28 December 2004, 29 & 30 September 2005 and 27 January 2006
Intertidal Assemblages at Black Point	Rocky shore/ artificial shoreline Quantitative (belt transects at 6 locations) survey, three 100 m belt transects (at high, mid and low intertidal zones) for each location, covered both wet and dry seasons	22 & 23 March and 15 & 30 July 2004.
Intertidal Assemblages at Shek Pik	Rocky shore/ artificial shoreline Quantitative (belt transects at 1 locations) survey, three 100 m belt transects (at high, mid and low intertidal zones) covered both wet and dry seasons. Sandy Shore Quantitative (line transects at 3 locations) survey, 50 x 50 x 50cm core at three points (high, mid and low intertidal zones) along each of the transects, covered both wet and dry seasons.	30 August 2005 & 14 March 2006
Subtidal Benthic Assemblages	Quantitative grab sampling survey; covered both wet and dry seasons. Six stations sampled in each of 14 locations.	25 & 26 February, 5 & 6 July, 9 September and 8 November 2004, 23 September 2005 and 13 December 2005
Subtidal Hard Bottom Habitat (Coral)	Quantitative (Rapid Ecological Assessment (REA) technique, a total of twenty three 100 m transects at 15 locations) and qualitative (recorded within Study Area and areas in the vicinity, 3 locations); covered wet season.	9 & 15 May 2004, 29,30 September & 3 October 2005.
Marine Mammal *	Land-based visual survey during daytime, 5 days per month and 6 hours per day, covered four seasons and 12 months.	13, 14, 21, 23 & 26 February, 8, 9, 10, 17 & 18 March, 16, 19, 20, 21 & 26 April, 10, 12, 14, 19 & 25 May, 10, 14, 17, 18 & 28 June 2004, 23, 26, 27, 28 & 29 July 2004, 25, 26, 27, 30 & 31 August, 6, 7, 13, 14 & 22 September 2004, 27, 28, 29, 30 & 31 October 2004, 16, 17, 24, 25 & 26 November 2004, 16, 21, 28, 30 & 31 December 2004, 10, 12, 14, 17 & 28 January 2005
	Quantitative vessel based survey using line transect methods spanning Hong Kong western waters (Deep Bay, Southwest Lantau, Northwest Lantau and West Lantau) 6 days per month.	18, 19, 20,,21, 22, 25, 26, 27 July 2005, 3, 4, 5,15,24 & 25 August 2005, 5,7,15, 16 & 20 September 2005, 5, 6, 7, 17, 18 & 19 October 2005, 22, 24, 25, 28, 29 & 30 November 2005, 6,7,8 & 22 December 2005, 13, 16, 17, 19, 20 & 24 January 2006, 1, 2, 3, 7, 8 & 9 February 2006, 17, 23, 28, 29, 31 March 2006, 3, 6, 18, 25, 26, 27 April 2006, 2, 4, 8, 9, 10, 11 May 2006.

Note: * Vessel-based surveys covered the period July 2005 – May 2006.

No surveys were considered necessary for epifaunal assemblages as a review of the available literature provided sufficient evidence of a low ecological value habitat in the waters surrounding the proposed LNG terminal on South Soko and along the submarine pipeline route.

Survey methodologies have been selected to follow standard and accepted techniques for marine ecological surveys. In addition, each methodology has been previously conducted as part of other Environmental Impact Assessments (EIA) studies, accepted under the Hong Kong Environmental Protection Department Environmental Impact Assessment Ordinance (EIAO).

Survey schedules were undertaken in accordance with the Environmental Impact Assessment Ordinance, Cap.499 Guidance Note - Ecological Baseline Survey For Ecological Assessment, specifically in terms of the following:

· Duration of Survey;

· Seasonality;

· Types of Survey Period; and

· Survey Effort.

The following sections present the methodology and results for each marine ecological survey undertaken as part of the assessment of marine ecological baseline conditions.

9.3.8 Intertidal Habitats

Methodology

Survey Locations

Both rocky and sandy intertidal habitats were surveyed. On the shores of South Soko, a total of nine quantitative rocky shore transect surveys were conducted in the both the wet and dry seasons, of which five were on natural rocky coastline and four on artificial rocky coastline. A further 6 sites on natural rocky shoreline on the south coast of South Soko were spotchecked due to the steep slopes and exposed nature of the shoreline that did not allow transect surveys. Two quantitative sandy shore surveys were also conducted in the study area.

Owing to reclamation at Black Point required for a Gas Receiving Station, surveys, six quantitative rocky shore surveys were conducted on the shores of Black Point, of which two were on natural rocky coastline and four on artificial rocky coastline.

In addition, a quantitative transect survey was conducted at one site on natural rocky shore at Shek Pik where the submarine cable and watermain would land. In addition, quantitative surveys were conducted on the sandy shore. Qualitative surveys were also undertaken in the surrounding areas of the landing site of the submarine cable and watermain. Owing to the presence of Shek Pik Prison access to the western shores of Tung Wan Bay was not authorised.

The survey transects were presented in Figures 9.5 & 9.6.

Survey Methodology

Rocky Shore and Artificial Shoreline

A 100m transect tape was laid horizontally along the rocky and artificial shoreline at 2 metres above chart datum (CD). When tidal height was below 1m, transects could be started, local tide tables were used to assess tidal height at the site and times of surveys were adjusted accordingly. Random numbers between 1 and 100 were generated before the survey and these numbers corresponded to metres along the transect at which quadrats should be placed. Three sets of random numbers were generated per transect to represent upper, mid and low transects.

A 50cm x 50cm quadrat was used to assess abundance and distribution of flora and fauna. All fauna found within the quadrat were recorded to species level to allow density per square metre to be calculated. Sessile fauna such as barnacles and oysters recorded in samples were not counted but estimated as percentage cover on the rock surface. Species of algae (encrusting, foliose and filamentous) were also identified and recorded by estimating the percentage cover within the sample quadrat.

On the south coast of South Soko, at sites with steep, impassable terrain where it was not possible to deploy transects, the accessible section of the coast was spot checked and qualitative notes on intertidal communities and ecological features were recorded.

Sandy Shore

On sandy shores, three line transects were deployed from the low tide mark up to the high tide mark and the presence of organisms were noted. At three points (1m, 1.5m and 2m above CD) along each of the transects, a 50 x 50 x 50cm core was removed and carefully sorted. All macrofauna visible to the naked eye within the sample core were identified and recorded.

Results of Intertidal Surveys at South Soko

Intertidal surveys have been conducted over two seasons, wet and dry. The date of each survey at each location is presented in Table 9.4Table 9.4. There were three types of coastal habitats, including sandy shore, natural rocky shore and artificial shoreline, recorded within the Study Area (Figure 9.7).

Table 9.4 Description of the Survey Transects/ Spotchecks and Survey Dates for Intertidal Hard Bottom Surveys on South Soko Island

Transect	Site Description	Date of Survey
		Dry Season	Wet Season
Artificial Shoreline
T1	Located in Sai Wan, shoreline is made up of large boulders and is relatively steep.	8 Mar 2004	28 July 2004
T2	Large granite boulders make up the majority of the substrate on this relatively steep sided shoreline	8 Mar 2004	28 July 2004
T3	Located in Sai Wan, the shoreline was disturbed.	8 Mar 2004	29 July 2004
T7	Large granite boulders make up the majority of this steep rocky artificial coastline.	28 Dec 2004	14 Sept 2004
Rocky Shore
T4	Located in Sai Wan, natural shallow sloping rocky shoreline consisting of mixture of smaller boulders at the low tide mark gradually getting larger further up the shoreline.	9 Mar 2004	29 July 2004
T5	Located in Pak Tso Wan, natural shallow sloping rocky shore line consisting of mixture of smaller boulders at the low tide mark gradually getting larger further up the shoreline.	9 Mar 2004	29 July 2004
T6	Transect 6 is a very steep natural shoreline on the northern shoreline of Tung Wan.	17 Dec 2004	14 Sept 2004
T8 (SC)	Located on southwest coast, shore is very steeply sloped bedrock	27 Jan 2006 (spotcheck)	29 Sept 2005 (spotcheck)
T9	Rocky shore comprised large scattered boulders, which is located in a small bay on the south side of the island	27 Jan 2006 (spotcheck)	29 Sept 2005
T10(SC)	Shore was inaccessible but was observed to be comprised of large boulders	27 Jan 2006 (spotcheck)	29 Sept 2005 (spotcheck)
T11(SC)	Steep inaccessible rocky shore with large boulders	27 Jan 2006 (spotcheck)	29 Sept 2005 (spotcheck)
T12(SC)	Steep impassible bedrock with large boulders on the south side of the island	27 Jan 2006 (spotcheck)	30 Sept 2005 (spotcheck)
T13(SC)	Steep, inaccessible rocky headland on south coast.	27 Jan 2006 (spotcheck)	30 Sept 2005 (spotcheck)
T14	Shallow sloping boulder shore comprising medium and large sized boulders with occasional patches of sand and shell debris.	27 Jan 2006 (spotcheck)	30 Sept 2005
T15(SC)	Steep jagged boulders and steep sloping bedrock and large boulders.	27 Jan 2006 (spotcheck)	30 Sept 2005 (spotcheck)
Sandy Shore
SS1	Located in Sai Wan, moderately sloping shoreline made up of reasonably coarse grained sand.	9 Mar 2004	29 July 2004
SS2	Located in Tung Wan, the beach is moderately sloping and made up of medium grained sand.	17 Dec 2004	14 Sept 2004

Rocky Shore and Artificial Shoreline

Dry Season

Rocky shore flora and fauna present on the shore at South Soko recorded during the dry season were common and widespread species, typical of semi exposed rocky shores in Hong Kong. None of the species recorded are considered to be of conservation interest.

The distribution of intertidal biota at different tidal heights on the shore followed typical vertical zonation patterns found in Hong Kong. Survey data of the quantitative transect surveys and spotcheck observations are presented in Tables 1 – 3 of Annex 9-A.

The high shore was dominated by the littorinid snails (periwinkles), Nodolittorina spp. Particularly on the wave exposed areas, stalked barnacles, Capitellum mitella occurred in crevices into the high shore. On the mid and low shore were found a variety of marine snails (including Monodonta labio, Thais clavigera, Nerita albicilla, Planaxis sulcatus, Lunella coronata and Chlorostoma arygrostoma), limpets (including Cellana toreuma, Nipponacmea concinna, Patelloida pygmea, Patelloida saccharina, Siphonaria japonica and Siphonaria lacinosa) barnacles (including Tetraclita japonica, Tetraclita squamosa, Capitellum mitella, Megabalanus volcano and Balanus amphitrite) and bivalves (including Saccostrea cucullata, Septifer virgatus and Barbatia virescens). Other fauna found on the shore included tubeworms (Hydriodes sp.), crabs (Grapsus albolineatus and Hemigrapsus sp.), chitons (Acanthopleura japonica), sea anemones (Haliplanella lineata) and rockpool fish (Bathygobius fuscus).

Algal cover recorded in the dry season was dominated by the encrusting algae Pseudulvella applanata and Hildenbrandtia rubra at the mid shore and erect red turf algae, Gelidium pusillum at the low shore. Other algae recorded incuded Ulva sp., pink encrusting algae, Endarachne binghamiae, Hincksia mitchelliae, Sargassum sp., and the cyanobacteria Kyrtuthrix maculans.

Wet Season

The species composition of the intertidal organisms during the wet season was similar to that of the dry season, with a total of 48 species on the rocky shore and 22 species on artificial shoreline (Tables 4, 5 & 6 of Annex 9-A). The major differences between the seasons were the abundance of littorinid snails and rock oyster. The abundance of littorinid snails recorded during the wet season was much lower than those recorded during dry season, and vice versa for rock oyster. The total abundance of the intertidal organisms recorded in wet season was generally lower than the dry season.

Sandy Shore

The sandy shores at South Soko supported a very low species diversity which is a typical feature of mobile sandy shores with unstable substrates ([39]). The sand at SS1 was coarse grained and the sand at SS2 was fine grained, and the only species to be recorded in any of the cores was Donax spp. These bivalves were recorded in low numbers on the both of the shores.

Results of Intertidal Surveys at Black Point

Intertidal surveys have been conducted over two seasons, wet and dry. The date of each survey at each location is presented in Table 9.5. There were two types of coastal habitats, including natural rocky shore and artificial shoreline, recorded within the Study Area (Figure 9.8).

Table 9.5 Description of the Survey Transects and Survey Dates for Intertidal Hard Bottom Surveys at Black Point

Transect	Site Description	Date of Survey
		Dry Season	Wet Season
Natural Shoreline
T1	Transect 1 is the furthest south of the rocky shore transects at Black Point and is a very steep natural shoreline made up of bedrock and the occasional boulder.	23 Mar 2004	15 July 2004
T2	Bedrock interspersed with a few large boulders and ranges from very steep to moderately steep sloping rock faces.	23 Mar 2004	15 July 2004
Artificial Shoreline
T3	Southernmost artificial shoreline to the power stations cooling water outlet. Site consisted of steep large boulders.	23 Mar 2004	15 July 2004
T4	South of the power stations cooling water outlet. Steep artificial seawall consisting of large boulders.	22 Mar 2004	30 July 2004
T5	Adjacent to the power stations cooling water outlet. Steep artificial seawall consisting of large boulders.	22 Mar 2004	30 July 2004
T6	Located on the artificial shoreline on northern shore of Black Point power station. Steep artificial seawall consisting of large boulders.	22 Mar 2004	30 July 2004

Rocky Shore and Artificial Shoreline

Dry Season

The littorinid snails, including Nodilittorina radiata, N. vidua and Littoraria articulata, were the dominant species in the high intertidal zone on the rocky shore and artificial shoreline during the dry season at Black Point (Tables 8 and 10 of Annex 9-A). The predatory gastropod Thais clavigera (the common dogwhelk), limpets (ie Nipponacmea concinna and Siphonaria japonica) and snail (Monodonta labio and Planaxis sulcatus) were recorded in the mid and low shore region. Sessile filter-feeding organisms such as the rock oyster (Saccostrea cucullata) and barnacles (Capitulum mitella, Tetraclita japonica, T.squamosa, Balanus amphitrite) were also recorded on the shores (Tables 8 and 10 of Annex 9-A). There were only 2 types of algae, including Ulva sp. and encrusting algae, of low coverage recorded at Black Point during the dry season surveys.

In total, there were 21 species recorded on the natural and artificial shores. 12 species recorded on natural shoreline were also found on artificial shoreline (Tables 1 and 4 of Annex 9-A). Except littorinid snails, all of the recorded species were in low abundances.

Wet Season

The species composition of the intertidal organisms during the wet season is similar to that of the dry season, with a total of 15 species on artificial shore and 12 species on natural shoreline (Tables 9 and 11 of Annex 9-A). The major differences between the seasons were the abundance of littorinid snails and rock oyster. The abundance of littorinid snails recorded during the wet season were much lower than those recorded during dry season, and vice versa for rock oyster. The total abundance of the intertidal organisms recorded in wet season was generally lower than the dry season.

Results of Intertidal Surveys at Shek Pik

Intertidal surveys have been conducted over two seasons, wet and dry. The date of each survey at each location is presented in Table 9.6Table 9.6.

There were two types of coastal habitats, rocky shore and sandy shore (Figure 9.9).

Table 9.6 Description of the Survey Transects and Survey Dates for Intertidal Hard Bottom and Intertidal Soft Bottom Surveys at Shek Pik

Transect	Site Description	Date of Survey
		Dry Season	Wet Season
Natural Rocky Shoreline
T1	Transect 1 is located on the east coast of Tung Wan and consisted of sheltered shallow sloping rocky shore consiting of bedrock and medium size boulders.	14 March 2006	30 August 2005
Sandy Shoreline
T2, T3, T4	Transects were laid on the sandy shore located next to the pier.	14 March 2006	30 August 2005

Rocky Shore

Dry Season

The rocky shore supported a low diversity of flora and fauna. The shore was dominated by the rock oyster, Saccostrea cucullata and with a high cover of Enteromorpha macroalgae. All biota are common and widespread and no species of note were found during the survey.

Wet Season

Surveys indicated low abundance and relatively low diversity of rocky shore fauna consiting of a species which are common and widespread in Hong Kong. The rock oyster (Saccostrea cucullata) dominated the shore and attained high cover on the mid and low shores. No notable species were found during the survey.

Sandy Shore

Dry Season

Survey of the sandy shore during the dry season encountered several borrows of the common Ghost Crab Ocypode cordimana. This shore appeared to be devoid of other burrowing or surface-dwelling fauna.

Wet Season

Survey on the sandy shore at Shek Pik encountered no fauna. Sandy shores are unstable and mobile habitat, which are subject to desiccation especially during the hot summer months. Few species are able to tolerate these conditions, which may account for the absence of biota recorded at this site.

9.3.9 Comparison of South Soko Intertidal Habitats With Other Hong Kong Sites

The intertidal organisms found on South Soko Island are typical of those found in similar habitats in Hong Kong. In comparison to other sites, overall species richness of intertidal organisms recorded on South Soko Island was similar. For instance, the number of species found on the south coast of Soko (41 species) during the dry season was not markedly different to sites surveyed by ERM ([40]) on the west coast of Lamma (37 species) and Fa Peng & Pa Tau Kwu (44 species) (Figure 9.7). In addition, results revealed some pronounced differences in species richness on different shores on South Soko (Figure 9.10). In general, rocky shore locations which were more sheltered from wave action, had considerably lower number of species than sections of exposed rocky shore. Wet season surveys recorded 41 species of intertidal biota at the wave exposed southerly facing coast of South Soko compared to a combined total of 25 species at generally more sheltered locations on west and east coasts on the northern part of the island.

Figure 9.10 Comparison of Intertidal Fauna and Flora at Various Sites in Hong Kong (Sources: (a) ERM 1998 ([41]), (b) ERM 2000 ([42]), (c) Babtie BMT 1999 ([43]) and (d) Present Study)

9.3.10 Subtidal Hard Bottom Habitats

Methodology

The Rapid Ecological Assessment (REA) technique was employed in order to investigate the subtidal hard bottom habitat assemblages at the proposed LNG terminal on South Soko Island. The REA technique allows semi-quantitative information on the ecological attributes of a subtidal habitat to be obtained relatively simply without compromising scientific rigour. An explanation of the survey locations and the methodology employed using this technique is presented below.

Survey Locations

Survey locations were selected in order to provide detail on the hard bottom habitats both within the proposed development area of the LNG terminal at South Soko Island and at areas in close proximity to the development site. A total of eight locations were surveyed using quantitative REA technique, as follows:

Quantitative Surveys

· North West Point (Zone A)

· North Sai Wan (Zone B)

· East Sai Wan (Zone C)

· South Sai Wan (Zone D)

· West Tung Wan (Zone E1)

· North Tung Wan (Zone E2)

· North East Point (Zone E3)

· Lan Nai Wan (Zone E4)

· South Tai A Chau (Zone I)

· South Tai A Chau (Zone J)

· South Tai A Chau (Zone K)

· South Tai A Chau (Zone L)

· South Tai A Chau (Zone M)

· South Tai A Chau (Zone N)

· South Tai A Chau (Zone O)

· South Tai A Chau (Zone P)

· Yuen Kong Chau (Zone Q)

· Tai Lo Chau (Zone R)

In addition to the above, three locations were surveyed qualitatively, as follows:

· Ma Chau (Zone F)

· Yeung Chau (Zone G)

· Outer Sai Wan (Zone H)

A summary of the dive surveys is presented below in Table 9.7Table 9.7, and locations are shown in Figure 9.5.

Table 9.7 Number of Transects Surveyed at South Soko

Survey Site	Number of 50m Transects Surveyed	Total Length of Area Surveyed
Zone A	1 in shallow depth zone and 1 in deep depth zone	100m
Zone B	1 in shallow depth zone and 1 in deep depth zone	100m
Zone C	1 in shallow depth zone and 1 in deep depth zone	100m
Zone D	1 in shallow depth zone and 1 in deep depth zone	100m
Zone E	4 in shallow depth zone and 4 in deep depth zone	400m
Zone F	Qualitative survey in both shallow and deep depth zones
Zone G	Qualitative survey in both shallow and deep depth zones
Zone H	Qualitative survey in both shallow and deep depth zones
Zone I	1 in shallow depth zone	100m
Zone J	1 in shallow depth zone	100m
Zone K	1 in shallow depth zone	100m
Zone L	1 in shallow depth zone	100m
Zone M	1 in shallow depth zone	100m
Zone N	1 in shallow depth zone	100m
Zone O	1 in shallow depth zone	100m
Zone P	1 in shallow depth zone	100m
Zone Q	2 in shallow depth zone	200m
Zone R	3 in shallow depth zone and 2 in deep depth zone	500m
Total	23	1900m

Rapid Ecological Assessment (REA) Survey Method

REA surveys were undertaken using standard SCUBA equipment. An initial qualitative reconnaissance dive was conducted within the study area and based on this, a decision was made on site as to where to position transects. Areas where corals appeared to be the most abundant, or areas of high epifaunal density, were selected as preferred locations. As such, the coordinates of the chosen transects were identified in the field using a handheld Geographic Positioning System (GPS) unit and recorded for future reference.

REA Transects for Zones A to E were laid in two distinct depth zones

· Shallow depth zone: -2 to –5m CD and;

· Deep depth zone: -6 to –10m CD.

The depths of the transects were adjusted accordingly based on the substrate habitats and the presence or absence of hard and soft corals.

REA Transects for Zones I to Q were ~100m long and deployed in the shallow depth zone (-2 to -5/-6m). In the turbid western waters, it is known that 6m is typically the depth limit at which hermatypic hard corals grow due to prevailing highly turbid conditions. At Zone R, survey conditions allowed survey transects to be deployed along deep depth zone in addition to shallow depth zone.

Following the laying of the transect line, video footage was taken of the benthos along the transect and an assessment of the benthic cover (Tier I) and taxon abundance (Tier II) was undertaken in a swathe ~ 4 m wide, 2 m either side of each transect. Swimming speed whilst videoing was kept slower than 10m per minute to prevent blurring of video and to improve clarity. An explanation of the two assessment categories (Tiers) used in the surveys is presented below.

Tier I - Categorisation of Benthic Cover

Upon the completion of each transect, six ecological and seven substratum attributes were assigned to one of seven standard ranked (ordinal) categories (Table 9.8Table 9.8 and Table 9.9Table 9.9).

Table 9.8 Benthic Attribute Categories

Ecological	Substratum
Hard coral	Hard substrate
Dead standing coral	Continuous pavement
Soft coral	Bedrock
Antipatharia	Rubble
Macroalgae	Sand
Turf algae	Silt
	Boulders – large (>50cm), small (<50cm)

Table 9.9 Ordinal Ranks of Percentage Cover

Rank	Percentage Cover (%)
0	None recorded
1	<5
2	6-10
3	11-30
4	31-50
5	51-75
6	76-100

Tier II - Taxonomic Inventories to Define Types of Benthic Communities

An inventory of benthic taxa was compiled during each dive (ie each transect). Taxa were identified in situ to the following levels:

· Scleractinian (hard) corals to species wherever possible;

· Soft corals, anemones and conspicuous macroalgae were recorded according to morphological features and to genus level if possible.

· Other benthos (including sponges, zoanthids, ascidians and bryozoans) were recorded to genus level wherever possible but more typically to phylum plus growth form.

At the end of each dive, each taxon in the inventory was ranked in terms of abundance in the community (Table 9.10Table 9.10). These broad categories rank taxa in terms of relative abundance of individuals, rather than the contribution to benthic cover along each transect. The ranks are subjective assessments of abundance, rather than quantitative counts of each taxon.

Table 9.10 Ordinal Ranks of Taxon Abundance

Rank	Abundance
0	Absent
1	Rare
2	Uncommon
3	Common
4	Abundant
5	Dominant

Photographs of representative coral species located in the surveyed areas were taken and, where possible, photographs of the seabed composition were taken.

Results of Subtidal Hard Bottom Habitat Surveys

The surveys were performed on 9 May and 15 May 2004 as well as on 29 and 30 September and 3 October 2005. On all dates, the weather was sunny and the sea was calm. The visibility was poor and generally ranged between 0.3 m and 1.0 m and deteriorated with depth. Along each transect the seabed composition was identified and conditions were noted as shown in Table 9.11Table 9.11 and Table 9.12Table 9.12.

Coral Assemblages

Dive surveys at South Soko for this EIA Study yielded similar results as BCL (1997) ([44]) who reported that hard corals were in low abundance and diversity and dominated by species which are common in Hong Kong. In total, fifteen hard coral species and four octocoral species, were recorded within the Study Area (Table 9.13Table 9.13). The majority were common faviids, poritids and siderasteriids with three predominant species – Oulastrea crispata, Psammocora sp. and the ahermatypic cup coral Balanophyllia sp.. Corals occurred in extremely low abundance and percentage cover estimates ranged from 1-5%. Many live corals recorded were highly bioeroded by macroborers and barnacles. The majority of colonies exhibited partial mortality and at most survey sites a low percentage cover of dead coral was noted. Corals recorded are all common Hong Kong species with the exception of the relatively little known hard coral, the False Pillow Coral Pseudosiderastrea tayami at site J and K.

Following a recent AFCD commissioned study which among other goals, aimed to clarify the taxonomic identity of Hong Kong hard corals, the number of species known to be present in Hong Kong waters rose from about 50 to over 80 ([45]). Pseudosiderastrea tayami was among the recent discoveries on the revised Hong Kong species list. It was discovered in 2002 and confirmation of its identity was made in 2003 ([46]) ([47]). Owing to its small corallites, this species is difficult to identify in the field. South Soko is the second location in Hong Kong from where this species has been discovered. The other location is a site in the southern waters of Hong Kong at Lamma Island ([48]).

Site J, which is a small sheltered bay on the south coast of South Soko Island, currently possesses the highest abundance of this coral species of the two presently known sites in Hong Kong waters. There are indications of active recruitment with observations of coral colonies <5 cm diameter. Isolated colonies of this species were also recorded from Site K. This species lives in shallow water and exhibits a remarkable threshold for sedimentation tolerance and was observed to occur on silt covered boulders. Owing to limited number of sites where it is known to occur, this species is currently regarded as rare in Hong Kong waters. Outside Hong Kong, the species has a wide distribution from the western Pacific to Indian Ocean including Taiwan,, Vietnam, Thailand, Malaysia, Philippines, Indonesia, Northern Australia, India, East Africa, Madagascar and the Gulf of Arabia and the Red Sea. Globally, this coral is considered to be uncommon and cryptic in terms of its abundance ([49]) . Until its recent discovery in Hong Kong through the AFCD commissioned study involving world expert coral taxonomists, there were no records from the Chinese coast.

Table 9.11 Description of the Seabed Recorded Along Each Transect and The Qualitative Surveys

Transect	Depth	Description
A (shallow)	-3 mPD	The seabed was composed of mainly bedrock and boulders with sparse sandy substrate along the transect. No hard coral colonies were found. Small number of poorly growth of Euplexaura and coralline algae found at the hard surface.
A (deep)	-6 mPD	The seabed was mainly composed of sandy substrate with scattered boulders and rubbles. Only one colony of Euplexaura found.
B (shallow)	-1 to - 3 mPD	The seabed was mainly composed of boulders with sand and rubbles in between. Small number of poorly growth of Euplexaura were recorded.
B (deep)	-4 to –4.5 mPD	The seabed was composed of silt and prone sandy substrate. No sessile organisms were recorded.
C (shallow)	-1.2 to –3 mPD	The seabed was composed of boulders and in some parts with sand. The transect can be divided into 2 zones. The first zone (0-30m) was composed of boulders with scattered rubbles and cobbles. The second zone (30-50m) was mainly sandy with heavy silt. A common hard coral colony Oulastrea crispata was recorded along the transect.
C (deep)	-4 to –5 mPD	The seabed was composed of fine sand. No sessile organisms were recorded.
D (shallow)	-1 to -3 mPD	The seabed was mainly composed of sandy substrate with sparse boulders and rubbles along the transect. No corals were recorded.
D (deep)	-4 mPD	The seabed was mainly composed of silt and sandy substrate. No sessile organisms were recorded.
E1 (shallow)	-2.5 to -3 mPD	The seabed was composed of boulders and cobbles. Macro-algae grew well on the surface of the hard substrate. No hard corals were recorded along this transect.
E1 (deep)	-6.5 mPD	The bottom was composed of sandy substrate. No sessile organisms were recorded along this transect.
E2 (shallow)	-4.5 mPD	The bottom was composed of sandy substrate. Sponge, macro-algae, coralline algae were recorded on the hard substrate. No corals were recorded.
E2 (deep)	-6 to -7 mPD	The bottom was composed of sandy substrate with some rubble patches. About ten colonies of hard coral were recorded including Porites lobata, Psammocora superficialis, Echinophyllia sp, Favites abdita, Goniopora stutchburyi, Goniopora lobata and Oulastrea crispata. These colonies were scattered along the transect.
E3 (shallow)	-5 to –6mPD	The bottom was composed of bed rock and boulder. There were a number of octocorals including Dendronephthya and Euplexaura but the growth form and size was limited. An ahermaptypic coral Tubastrea was recorded.
E3 (deep)	-9mPD	The bottom was composed of sand substrate with some boulders and rubbles. Small number of octocorals including Dendronephthya and Euplexaura. An ahermaptypic coral Tubastrea sp. was also recorded.
E4 (shallow)	-4mPD	The bottom was composed of bed rock, boulder and sand. Small number of octocorals including Dendronephthya and Euplexaura.
E4 (deep)	-10mPD	The bottom was composed of sand substrate with some boulders and rubbles. Small number of octocorals including Dendronepthya and Euplexaura.
F	-3 to –9mPD	The bottom was composed of boulders, rubbles and sandy substrate in the shallow water. Small number of Euplexaura sp. were recorded. Some of the hard surfaces were covered with macro-algae. The deep region was mainly silt substratum and devoid of marine life.
G	-3 to –9mPD	In the shallow water, the bottom was composed of boulders and rubbles. Small number of Euplexeura sp. were recorded but their condition was very poor.
H	-3 to –5mPD	The bottom was mainly composed of sandy substrate.
I (shallow)	-2 to -6.4 mPD	Site comprised of large boulders with a visible layer of silt. Absence of coralline algae notable and sessile benthos comprised of isolated encrusting sponges and bryozoans, small, scattered hard coral colonies of three species: Oulastrea crispata, Psammocora sp. and the ahermatypic cup coral Balanophyllia sp. (the most abundant and recorded as common). Isolated octocorals were recorded and included small colonies of Dendronephthya and the gorgonian Euplexaura. Ahermatypic cup coral Dendrophyllia/Tubastrea sp. was recorded at 5-6m depth.
J (shallow)	-1.2 to -5.6 mPD	Site J encompassed a small sheltered and depositional bay of the southern section of South Soko. The main substrate composition was large boulders and the shallow upper subtidal area was dominated by encrusting corallines, sponges, oysters, barnacles and tube worms . The lower shallow subtidal (2-5/6 m depth) was extremely silty with a visible layer of silt on the surfaces of all boulders. Hard corals were recorded and included: Oulastrea crispata, Psammocora sp., Porites lobata, Coscinaraea sp., Balanophyllia sp. and the little known siderastreid Pseudosiderastrea tayami. This species was common at this site with numerous small colonies surrounded by thick layers on silt. Colonies ranged from 2-3 cm to >20 cm in diameter indicating active recruitment in this site. Isolated gorgonians were also recorded: Euplexaura and Echinomuricea. These gorgonians and the ahermatypic cup coral Dendrophyllia/Tubastrea sp. were recorded at slightly deeper depth than the hermatypic hard corals.
K (shallow)	-2 to -5.4 mPD	This site was similar to site J in terms of substratum and sessile benthos composition. Pseudosiderastrea tayami colonies were recorded as rare in abundance and the hard corals Oulastrea crispata, Psammocora sp., Porites lobata, Coscinaraea sp. and the ahermatypic cup corals Balanophyllia sp. and Dendrophyllia/Tubastrea sp. were all recorded in low abundances. A similar sessile invertebrates were observed as at site J with a dominance of encrusting sponges and bryozoans.
L (shallow)	-2 to -5 mPD	Site had a low abundance of hard corals: Oulastrea crispata, Psammocora sp., Balanophyllia sp., the poritid Goniopora stutchburyi and the faviid Lepastrea pruinosa. The ahermatypic cup coral Dendrophyllia/Tubastrea sp. and gorgonian Echinomuricea were recorded from deeper depths. Coralline algae was dominant in the upper shallows (0-2 m depth) and large boulder surfaces were encrusted with bryozoans, sponges, oysters, spiral tube worms and hydroids.
M (shallow)	-1 to -6 mPD	Site composed of large boulders. Hard corals recorded included: Oulastrea crispata (common), Goniopora stutchburyi, Psammocora sp., and Coscinaraea sp.. The ahermatypic cup coral Balanophyllia sp. was recorded as common and located on horizontal boulder surfaces, generally below 5 m depth.
N (shallow)	-2 to -7 mPD	Site encompassed a headland promontory. On the southeast side the benthic community was similar to I-M. On the northwest facing side of this headland there was less deposition, clean boulder surfaces and visibility improved to approximately 2 m due to a swift current running between South Soko and Yuen Kong Chau. On this side invertebrates were larger and more abundant, e.g., oysters, the bryozoan Schizoporella errata, the encrusting brown bryozoan, a variety of encrusting sponges and unidentified jewel anemones. Hard corals recorded were Psammocora sp., Plesiastrea versipora, Cyphastrea sp. and Leptastrea pruinosa. The Psammocora colonies were most abundant and often >30 cm in diameter and colonies of this species were recorded at >5 m depth. The ahermatypic cup coral Balanophyllia sp. was recorded as abundant in patches and located on horizontal boulder surfaces, generally below 5 m depth. Isolated gorgonians Euplexaura and Echinomuricea were noted and the odd, either small or with a diseased appearance, Dendronephthya colony was recorded on a spot dive below six metres.
O (shallow)	-1 to -5 mPD	A shallow site composed of small boulders leading to a sandy sloping seabed. Upper, shallow sections were composed of small boulders covered in encrusting corallines, barnacles and oysters. Lower, shallow sections were composed of scattered small boulders and sand. Benthic community composition was comprised of bryozoans, encrusting sponges, small sea urchins and sea cucumbers. This site recorded seven species of hard coral with majority noted as uncommon in abundance. The faviid Leptastrea pruinosa was common and colonies >40 cm diameter were noted. Other faviids included Cyphastrea sp. and Oulastrea crispata. Other corals were Psammocora sp. , Coscinaraea sp., Goniopora stutchburyi and a solitary, juvenile Turbinaria peltata colony. The ahermatypic cup coral Balanophyllia sp. was recorded but noted as rare at this site. A number of ghost nets were recorded within this survey site.
P (shallow)	-1 to -5 mPD	This site was a headland leading to a large beach. Seabed was composed of large boulders leading to a sandy seabed at shallower depths near the beach. Several hard coral species were recorded as common at this site: Oulastrea crispata, Psammocora sp. and Goniopora stutchburyi. Other corals recorded included: Porites lobata, Coscinaraea sp., Plesiastrea versipora and the ahermatypic cup coral Balanophyllia sp.. Gorgonians were rare with the odd Echinomuricea colony noted. Fouling and mobile invertebrates were similar in composition with an abundant category designated to the large, encrusting bryozoan Schizoporella errata, Diadema setosum (long-spined sea urchin) and Saccostrea sp. (oysters). Also recorded at this site were large mats of stalked zoanthids. A spot dive was also conducted at South Soko on the shore opposite P across the other side of beach inlet. A large boulder composed subtidal shore was covered in corallines, jewel anemones and barnacles in the upper shallows and encrusting bryozoans in the lower shallows. A hard coral band between 4-6 m depth was noted and consisted of isolated colonies of the same coral species as recorded for P.
Q1 (shallow)	-1 to -6.8 mPD	This survey dive was the western side of Yuen Kong Chau. Substratum comprised of large and small boulders between 0-5 m gradually sloping to a sand seabed (~6 m depth). The upper shallows were predominated by encrusting corallines, turf algae, barnacles, encrusting sponges and bryozoans. The lower shallows consisted of a similar suite of sessile and mobile invertebrates as recorded for South Soko and isolated hard coral and octocoral colonies (rare-uncommon). Five coral species were recorded – Oulastrea crispata, Psammocora sp., Porites, Goniopora stutchburyi and the ahermatypic Balanophyllia sp.. The gorgonian Echinomuricea was the only octocoral recorded. Dominant sessile invertebrates included the bryozoan Schizoporella errata, encrusting sponges and oysters. Numerous ghost nets were recorded on this survey. At the southwest end of the dive survey a small patch of dead Goniopora sp. were observed.
Q2 (shallow)	-1 to -6 mPD	This site encompassed the eastern side of the Yuen Kong Chau islet. The site comprised vertical bedrock (at the southern tip of the islet), and a mix of large and small boulders gradually sloping to a sand/silt seabed. Large barnacles, encrusting bryozoans and sponges predominated. Also recorded were oysters, and sea urchins including Diadema setosum and Anthocidaris crassispina. Isolated and small hard coral colonies were recorded and included: Psammocora sp., Goniopora stutchburyi (common), the faviids Oulastrea crispata, Cyphastrea sp. and Favites abdita, Coscinaraea sp. and the ahermatypic Balanophyllia sp..
R1 (shallow)	-2 to -8 mPD	These survey areas were comprised of a mix of large and small boulders with scattered, small sand patches gradually sloping to a silt seabed. A total of seven hard coral species were recorded and matched those recorded from South Soko and Yuen Kong Chau with predominant species such as Psammocora sp., Goniopora stutchburyi , Oulastrea crispata and the ahermatypic Balanophyllia sp.. Octocorals were recorded from R1 and R5 only. R1 possessed numerous small gorgonian colonies of Echinomuricea, unusual for such shallow depths, however, the majority of these colonies exhibited high partial and total mortality. R5 contained a few Dendronephthya and Euplexaura colonies on the eastern side of the channel. The sessile benthos was predominated by encrusting bryozoans such as Schizoporella errata, encrusting sponges, oysters, spiral tube worms, mussels (Perna viridis), jewel anemones and thick layers of encrusting masses of tube worms together with sponges and bryozoans. Coralline algae were encrusted on all boulder surfaces in the upper shallows.
R2 (shallow)	-2 to -8 mPD
R5 (shallow)	-4 to -7 mPD
R3 (deep)	- 8 to -10 mPD	Tau Lo Chau was the only location during 2005 surveys were dive conditions permitted REA surveys in the deep depth range of 6-10 m. Two surveys were conducted along the southwestern section of Tau Lo Chau and were comprised of large and small silt ladened boulders. These two survey sites possessed an atypical abundance of large, mature gorgonians (whips and fans) and large ahermatypic cup corals (Tubastrea/ Dendrophyllia sp.). Gorgonians identified were of the genera Euplexaura, Echinomuricea and Echinogorgia. There was a notable absence of other sessile or mobile invertebrates except for numerous hydroids and low records of encrusting sponges and bryozoans. With the exception of the cup corals no other hard coral species were recorded. Also of note was the number of gorgonian colonies with commensal anemones attached.
R4 (deep)	- 7 to -10 mPD

Table 9.12 Seabed Attributes Along the Survey Transects at South Soko

	A	A	B	B	C	C	D	D	E1	E1	E2	E2	E3	E3	E4	E4	I	J	K	L	M	N	O	P	Q1	Q2	R1	R2	R3	R4	R5
Transect depth (b)	s	d	s	d	s	d	s	d	s	d	s	d	s	d	s	d	s	s	s	s	s	s	s	s	s	s	s	s	d	d	s
Seabed attributes (a)
Hard substrate
Continuous pavement
Bedrock	4	1					1		1		1		3		3
Rubble		1	1		1		1		1	1	1	1		1		1
Sand	1	2	2	2	2		3		1		1	4		4	1	2				1			3	3	3	2	2	2	2	3	2
Silt				4	1	5		5		4												2	2						2	2
Boulders – large		1	3		2		1		2		4	1	2	1	2	2	6	6	5	5	6	6		5	4	4	4	4	4		5
Boulders – small		1	1		1				2		1	1	1	1		1			3				5		3	2		3	3	4	2
Ecological attributes (b)
Hard coral					1							1	1	1			1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
Dead standing coral																	1	1	1	1	1		1	1	1	1	1			1
Soft coral	1	1	1										1	2	1	2	1	1	1	1		1		1	1	2	1	1	2	3	1
Antipatharia
Macroalgae	1		2		2		1		4		1					2

Notes: (a) 1=<5% Cover, 2= 6-10% Cover, 3 = 11-30% Cover, 4 = 31-50% Cover, 5 = 51-75% Cover, 6 = 76-100% Cover.

(b) A to E = transect line; s= shallow water; d=deep water

Table 9.13 Coral Species Recorded Along the Survey Transects at South Soko

	A	B	C	D	E1	E2	E3	E4	I	J	K	L	M	N	O	P	Q1	Q2	R1	R2	R5	R3	R4
Hard Coral Species (a)
Porites lobata	0	0	0	0	0	1	0	0	0	1	1	0	0	0	0	2	1	0	0	0	0	0	0
Psammocora spp.	0	0	0	0	0	1	0	0	1	1	2	2	2	3	2	3	2	3	1	0	2	0	0
Coscinarea sp.	0	0	0	0	0	0	0	0	0	1	1	0	2	0	2	2	0	1	0	0	0	0	0
Pseudosideratrea tayami	0	0	0	0	0	0	0	0	0	3	1	0	0	0	0	0	0	0	0	0	0	0	0
Turbinaria peltata	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	2	2	0	0	0	2	2
Balanophyllia sp.	0	0	0	0	0	0	0	0	3	2	3	3	3	3	2	2	3	2	2	3	0	3	3
Favites abdita	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0
Plesiastrea versipora	0	0	0	0	0	0	0	0	0	0	0	0	0	2	0	2	0	0	0	0	2	0	0
Leptastrea pruinosa	0	0	0	0	0	0	0	0	0	0	0	1	0	2	3	0	0	0	0	0	0	0	0
Cyphastrea sp.	0	0	0	0	0	0	0	0	0	0	0	0	0	2	2	0	0	2	0	0	2	0	0
Echinophyllia sp	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Goniopora stutchburyi	0	0	0	0	0	1	0	0	0	0	0	1	2	0	2	3	2	3	2	2	0	0	0
Goniopora lobata	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Oulastrea crispata	0	0	1	0	0	1	0	0	2	2	2	3	3	0	2	3	2	2	3	3	0	0	0
Tubastrea sp. / Dendronophyllia sp.	0	0	0	0	0	0	1	0	2	2	2	2	2	2	0	0	2	2	0	0	0	2	2
Octocoral Species (a)
Dendronephthya sp.	0	0	0	0	0	0	1	1	1	0	0	0	0	2	0	0	0	2	0	0	2	2	0
Euplexeura sp.	1	1	0	0	0	0	1	1	2	1	0	0	0	2	0	0	0	0	1	0	0	3	3
Echinomuricea sp.	0	0	0	0	0	0	0	0	0	1	0	1	0	2	0	1	2	1	3	0	0	3	3
Echinogorgia sp.	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	3	3

Note: (a). 0=absent, 1=rare, 2=uncommon, 3=common, 4=abundant, 5=dominant

Also note Sites F and G were surveyed by spot dive so that REA data were not collected for these sites.

IMPORTANT

The ranks shown in the Table above indicate the relative abundance of each coral in relation to other corals in the community. In other words, these broad categories rank taxa in terms of relative abundance of individuals, rather than the contribution to benthic cover along each transect. The ranks are subjective assessments of abundance, rather than quantitative counts of each taxon. For instance, if a coral is ranked as ‘common’, it means it was more frequent than other coral species along the transect. It should be borne in mind that coral cover along all of the transects where corals occurred was very low (<5% cover).

9.3.11 Comparison of South Soko Subtidal Hard Surface Habitats With Other Hong Kong Sites

Coral coverage at South Soko is very low due to its geographic location and the heavy influence (ie freshwater runoff and siltation) of the Pearl River Estuary on the marine conditions. The generally turbid waters are acknowledged as limiting colonisation and the rate of coral growth in the Western and South Western waters of Hong Kong.

Previous studies and surveys ([50]) ([51]) ([52]) have shown that live coral cover in Hong Kong may reach high levels where favourable environmental conditions prevail. For instance, coral cover was recorded at 71.9% at Coral Garden in Hoi Ha Wan. Figures 9.11 & 9.12 show the low number of coral species and low coral cover that was found at South Soko in comparison to other sites in Hong Kong’s southern and western waters.

Figure 9.11 Comparison of Number Coral Species recorded at Other Sites in Hong Kong (Sources: +Present Study, *AFCD 2002 ([53]) , ºMCL 1999 ([54]) and #ERM 2001 ([55]) )

Figure 9.12 Comparison of Percentage Live Coral Cover at Other Sites in Hong Kong (Sources: +Present Study, *AFCD 2002 ([56]), ºERM 1998 ([57]) and #ERM 2002 ([58]))

As can be seen from Figure 9.12 coral cover at South Soko is very sparse (<3% cover) in relation to coral sites further to the east of Hong Kong such as the Ninepins where, for instance, 23.1% live coral cover was reported. Higher coral cover than South Soko was also previously recorded at the Penny’s Bay Site (8.99% cover) at East Lantau. The low coral cover in western waters of Hong Kong is a direct consequence of the naturally brackish, turbid estuarine waters discharged by the Pearl River into this area. Such conditions are unfavourable to coral settlement growth and survival, and these naturally occurring conditions account for the low coral abundance in Hong Kong western waters such as at South Soko.

9.3.12 Epifaunal and Infaunal Assemblages (Benthos)

Survey Methodology

Sampling Locations

Benthic samples were collected at four sites representative of subtidal soft bottom habitats in the vicinity of the proposed LNG terminal at South Soko Island. Following changes in site layout plans to locate the LNG jetty on the southern side of South Soko, an additional four sites were sampled to investigate the subtidal soft bottom habitats off the southern side of South Soko. A further eight sites were sampled along or within close proximity to the submarine pipeline corridor in order to collect information on the infaunal assemblages in these waters. Sampling sites were as follows:

· South Soko Island (SK1 to SK 4)

· Southern South Soko (SSK 1 to SSK4)

· Adamasta Channel (AC)

· Peaked Hill Island (PH)

· Tai O (TO)

· Lung Kwu Chau and Sha Chau Marine Park (MP1 and MP2)

· Urmston Road (UR)

· Black Point (BP1 and BP2)

The locations of each survey site are shown in Figure 9.13.

Field Sampling Methodology

At each survey site, six stations approximately 50 m apart were established and one grab sample was collected from each station. Stations were sampled using a modified Van Veen grab sampler (960 cm2 sampling area; 11,000 cm3 capacity) with a supporting frame attached to a swivelling hydraulic winch cable.

Sediment from the grab samples were sieved on board the survey vessel. The sediments were washed onto a sieve stack (comprising 1 mm and 500 (m meshes) and gently rinsed with seawater to remove all fine material. Material remaining on the two screens following rinsing was combined and carefully rinsed using a minimal volume of seawater into pre-labelled thick triple-bagged ziplock plastic bags. A 20% solution of buffered formalin containing Rose Bengal in seawater was then added to the bag to ensure tissue preservation. Samples were sealed in plastic containers for shipment to the taxonomy laboratory for sorting and identification.

Laboratory Techniques

The benthic laboratory performed sample re-screening after the samples had been held in formalin for a minimum of 24 hours to ensure adequate fixation of the organisms. Individual samples from the 500 mm and 1 mm2 mesh sieves were gently rinsed with fresh water into a 250 mm sieve to remove the formalin from the sediments. Sieves were partially filled while rinsing a specific sample to maximize washing efficiency and prevent loss of material. All material retained on the sieve was placed in a labelled plastic jar, covered with 70% ethanol, and lightly agitated to ensure complete mixing of the alcohol with the sediments. Original labels were retained with the re-screened sample material.

Standard and accepted techniques were used for sorting organisms from the sediments. Small fractions of a sample were placed in a petri dish under a 10-power magnification dissecting microscope and scanned systematically with all animals and fragments removed using forceps. Each petri dish was sorted at least twice to ensure removal of all animals. Organisms representing major taxonomic groups including Polychaeta, Arthropoda, Mollusca, and miscellaneous taxa were sorted into separate, labelled vials containing 70% ethanol.

Taxonomic identifications were performed using stereo dissecting and high-power compound microscopes. These were generally to the family level except for dominant taxa, which were identified to species. The careful sampling procedure employed minimizes fragmentation of organisms. If breakage of soft-bodied organisms occurs, only anterior portions of fragments were counted, although all fragments were retained and weighed for biomass determinations (wet weight).

Results of Benthic Surveys

Survey Dates and Conditions

Grab samples were collected from sites off the north, east and west coasts of South Soko (SK1 to SK4) as well as along the proposed pipeline alignment (AC PH, TO, MP1, MP2, UR, BP1 and BP2) in both the dry (25-26th February 2004 and 8th November 2004) and wet (5-6th July 2004 and 9th September 2004). Additional surveys to collect grab samples from sites off the southern side of South Soko (SSK1 to SSK4) were conducted in the wet season (23rd September 2005) and dry season (13th December 2005).

Dry Season Survey Results

A total of 4,309 individual organisms were collected from the 96 grab sampling stations in the vicinity of the South Soko Island and along the preliminary submarine pipeline corridor during the dry season surveys in 2004 and 2005. The specimens belong to 6 Phyla with a total of 69 families and 105 genera identified. A complete set of raw data is presented in Table 14 of Annex 9-A.

A breakdown of dry season 2004 benthic data by site revealed relatively large differences in terms of number of individuals, biomass and taxonomic richness (here represented by number of families of infaunal organisms). The South Soko Island site SK3 recorded the highest number of individuals with mean of 161 individuals station-1 (± 279.9 SD) recorded, equating to 1613.7 m-2 (± 2946.2 SD) (Table 9.14Table 9.14). In comparison, Tai O (TO) and the Sha Chau and Lung Kwu Chau Marine Park (MP1 and MP2) recorded the lowest mean numbers of individuals (13.0 (± 4.0 SD), 15.0 (± 6.2 SD) and 14.3 (± 12.8 SD) station-1), respectively. The Adamasta Channel (AC) also recorded comparatively high numbers, with 104.0 station-1 (± 61.0 SD) recorded. As can be seen from the standard deviation at each site, the numbers varied greatly between stations, particularly at those sites with high numbers of individuals (SK1 and BP2).

Table 9.14 Grab Sample Composition (Infaunal Assemblages) of Each Sample Site for the Soft Bottom Habitat Surveys at South Soko Island and along the Preliminary Submarine Pipeline Corridor during the Dry Season 2004 and 2005

Site	Number of Stations Sampled	Total Number of Infaunal Individuals	Mean Number of Individuals Station-1 (±SD)	Mean Number of Individuals m-2 (±SD)	Total Biomass (g wet weight)	Mean Taxonomic Richness (No. Families) Station-1 (±SD)	Mean Taxonomic Richness (No. Genera) Station-1 (±SD)	Mean Biomass Individual-1 (g wet weight)
SK1	6	465	77.5 (± 50.7)	806.0 (± 527.0)	27.0	14.8 (± 4.9)	16.2 (± 5.2)	0.06
SK2	6	120	20.0 (± 4.9)	208.0 (± 50.5)	11.4	9.8 (± 2.9)	10.7 (± 2.7)	0.09
SK3	6	931	161 (± 279.9)	1613.7 (± 2946.2)	82.8	10.5 (± 4.3)	11.3 (± 4.4)	0.09
SK4	6	306	51 (± 40.2)	530.4 (± 418.2)	26.7	14.8 (± 4.40)	16.5 (± 5.28)	0.09
SSK1	6	198	33.0 (± 8.8)	343.8 (± 92.0)	14.9	13.8 (± 1.5)	13.8 (± 1.5)	0.08
SSK2	6	94	15.7 (± 4.4)	163.2 (± 46.0)	5.5	9.7 (± 2.7)	9.7 (± 2.7)	0.05
SSK3	6	213	35.5 (± 27.0)	369.8 (± 281.0)	89.3	12.7 (± 4.5)	12.7 (± 4.5)	0.04
SSK4	6	175	29.1 (± 14.2)	303.8 (± 147.8)	89.4	14.0 (± 2.7)	14.0 (± 2.7)	0.05
AC	6	624	104.0 (± 61.0)	1081.6 (± 644.8)	130.7	12.2 (± 4.7)	13.2 (± 5.6)	0.21
PH	6	255	42.5 (± 16.4)	442.0 (± 170.5)	6.1	6.2 (±1.9)	6.7 (± 1.6)	0.02
TO	6	78	13.0 (± 4.0)	135.2 (± 41.6)	7.2	8.3 (± 1.9)	8.7 (± 2.2)	0.09
MP1	6	90	15.0 (± 6.2)	156.0 (± 64.8)	9.9	7.2 (± 3.3)	7.5 (± 4.0)	0.11
MP2	6	86	14.3 (± 12.8)	149.1 (± 133.1)	12.8	6.2 (± 5.0)	6.7 (± 5.0)	0.15
UR	6	91	15.2 (± 13.7)	157.7 (± 142.8)	8.2	5.5(± 3.5)	5.8 (± 3.8)	0.09
BP1	6	203	33.8 (± 39.3)	351.9 (± 408.7)	56.9	6.7 (± 4.1)	6.8 (± 4.4)	0.28
BP2	6	380	63.3 (± 47.8)	658.7 (± 497.1)	25.2	11.0 (± 5.8)	12.0 (± 6.1)	0.07

The highest biomass in the dry season 2004 was recorded at the Adamasta Channel (AC) site, with 130.7g wet weight (Table 9.12). Two south South Soko sites (SSK3 and SSK4), the South Soko SK3 site and Black Point (BP1) also recorded comparatively high biomass in contrast to the other sites surveyed, with a total biomass of 89.3, 89.4, 82.8 and 56.9 g wet weight, respectively.

South Soko Island site SK1 and SK4 had the most diverse infauna present in the dry season 2004, with a mean number of 14.8 (± 4.4 SD) and 14.8 (± 4.9 SD) families, and 16.2 (±5.2 SD) and 16.5 (± 5.3 SD) genera station-1 respectively. Also with comparatively high diversity were south Soko sites SSK4 and SSK1, with a mean number of 14.0 (+ 4.7 SD) and 13.8 (+ 1.5 SD) families, and 14.0 (± 4.7 SD) and 13.8 (± 1.5 SD) genera station-1 respectively. Similarly to both abundance and biomass, the Adamasta Channel (AC) site also recorded a high diversity in comparison to other sites surveyed under the dry season survey.

Overall, the majority (67.8%) of the numbers of infaunal organisms recorded during the dry season surveys were from the Phyla Annelida. The remainder were Mollusca (18.1%), Arthropoda (4.5%), Echinodermata (3.8%), Sipuncula (3.0%) and Echuira (2.8%). .

The polychaete worm Prionospio queenslandica from the family Spionidae, was the most abundant species from the surveys, particularly at the Black Point (BP1 and BP2), South Soko (SK1) and Adamasta Channel (AC) sites. No rare or uncommon species of infauna were recorded in the dry season 2004 survey at South Soko or along the preliminary submarine pipeline corridor. Nevertheless, one noteable epifaunal species, the amphioxus Branchiostoma belcheri, was recorded at South SK3 in the dry season. Details are provided at the end of this results section.

The composition of the infauna at each site in terms of numerical abundance of organisms present (grouped by class) in the dry season surveys, is presented in Figure 9.14. The majority of organisms collected were clams from the class Bivalva, owing to the high number encountered at the South Soko (SK3) site. By comparison, numbers of bivalves at other sites were low so that overall Polychaetes were typically the dominant group at each site in terms of the numbers of individuals present.

Figure 9.14 Mean Numbers of Individuals per Station of Infaunal Organisms (Class level) from Benthic Samples collected at South Soko Island and along the Preliminary Submarine Pipeline Corridor during the Dry Season Surveys

The composition of infaunal assemblages at each site in terms of mean biomass of groups of organisms (by class) at each site is presented in Figure 9.15. The highest distribution of biomass was from Echiurida in the Adamasta Channel (AC). Other sites with generally higher levels of biomass include Echinoidea at the south South Soko SSK4 site, bivalva at the South Soko SK3 and south South Soko SSK3 sites, and Holothuroidea at Black Point (BP1).

Figure 9.15 Mean Biomass Station-1 Infaunal Organisms (Class level) from Benthic Samples collected at South Soko Island and along the Preliminary Submarine Pipeline Corridor during the Dry Season Surveys

Wet Season Survey Results

A total of 6,351 individual organisms were collected from the 96 grab sampling stations in vicinity of South Soko Island and along the preliminary submarine pipeline corridor during the wet season surveys in 2004 and 2005. The specimens belong to 7 Phyla with a total of 72 families and 111 genera identified. A complete set of raw data is presented in Table 15 of Annex 9-A.

A breakdown of wet season 2004 benthic data by site revealed relatively large difference in terms of number of individuals, biomass and taxonomic richness (here represented by number of families of infaunal organisms). The Urmston Road (UR) recorded the highest number of individuals with mean of 498.8 individuals station-1 (± 997.3 SD) recorded, equating to 5,188 m-2 (± 10,372.3 SD) (Table 9.15). By comparison, Southern South Soko (SSK2), Tai O (TO) and the Sha Chau and Lung Kwu Chau Marine Park (MP1 and MP2) recorded the lowest mean numbers of individuals (13.5 (± 7.1), 12.7 (± 2.5 SD), 10.3 (± 4.4 SD) and 9.3 (± 7.3 SD) individuals station-1, respectively). As can be seen from the standard deviation at each site, the numbers varied greatly between stations, particularly at those sites with high numbers of individuals (UR, SK3, SSK3 and BP1).

Table 9.15 Grab Sample Composition (Infaunal Assemblages) of Each Sample Site for the Soft Bottom Habitat Surveys at South Soko Island and along the Preliminary Submarine Pipeline Corridor during the Wet Season 2004 and 2005

Site	Number of Stations Sampled	Total Number of Infaunal Individuals	Mean Number of Individuals Station-1 (±SD)	Mean Number of Individuals m-2 (±SD)	Total Biomass (g wet weight)	Mean Taxonomic Richness (No. Families) Station-1 (±SD)	Mean Taxonomic Richness (No. Genera) Station-1 (±SD)	Mean Biomass Individual-1 (g wet weight)
SK1	6	149	24.8 (± 20.1)	258.3 (± 230.0)	50.4	11.2 (± 4.3)	11.3 (± 4.5)	0.34
SK2	6	88	14.7 (± 8.8)	152.5 (± 91.1)	122.6	7.2 (± 3.7)	7.2 (± 3.7)	1.39
SK3	6	822	137.0 (± 205.4)	1,424.8(± 2,136.3)	78.6	16.5 (± 4.2)	17.2 (± 4.0)	0.10
SK4	6	147	24.5 (± 19.3)	254.8 (± 201.2)	31.2	12.2 (± 5.04)	12.8 (± 5.71)	0.21
SSK1	6	211	35.2 (± 16.4)	366.3 (± 171.2)	35.5	11.3 (± 3.4	11.3 (± 3.4)	0.17
SSK2	6	81	13.5 (± 7.1)	140.6 (± 74.1)	36.8	8.7 (± 3.8)	8.7 (± 3.8)	0.45
SSK3	6	387	64.5 (± 56.6)	671.9 (± 589.4)	144.6	13.3 (± 3.8)	13.3 (± 3.8)	0.37
SSK4	6	240	40.0 (± 9.5)	416.7 (± 98.8)	53.6	12.0 (± 3.3)	12.0 (± 3.3)	0.22
AC	6	337	56.1 (± 21.2)	584.1 (± 220.8)	22.7	11.2 (± 3.7)	12.2 (± 4.1)	0.07
PH	6	133	22.2 (± 16.0)	230.5 (± 165.9)	2.92	5.5 (± 2.5)	5.7 (± 2.7)	0.02
TO	6	76	12.7 (± 2.5)	131.7 (± 26.0)	50.4	12.2 (± 5.0)	12.8 (± 5.7)	0.13
MP1	6	62	10.3 (± 4.4)	107.5 (± 45.9)	33.2	5.5 (± 2.1)	5.5 (± 2.1)	0.53
MP2	6	56	9.3 (± 7.3)	97.1 (± 75.8)	9.32	4.5 (± 1.9)	5.0 (± 2.3)	0.17
UR	6	2,993	499.0 (± 997.0)	5,187.9 (± 10,372.3)	174.5	7.0 (± 5.4)	7.3 (± 5.8)	0.06
BP1	6	335	55.8 (± 38.1)	580.7 (± 396.2)	161.4	10.0 (± 3.7)	10.8 (± 4.6)	0.48
BP2	6	234	39.0 (± 24.1)	405.6 (± 250.7)	376.6	8.0 (± 2.8)	8.5 (± 2.6)	1.61

The highest biomass recorded from the wet season surveys was at the Black Point (BP2) site, with 376.6 g wet weight. The Black Point Station (BP1), Southern South Soko (SSK3), South Soko Island (SK2) and Urmston Road (UR) also recorded comparatively high biomass in contrast to the other sites surveyed, with a total biomass of 161.4, 144.6, 122.6 and 174.5 g wet weight, respectively.

South Soko Island sites SK3, SK4 and SSK3 recorded the highest diversity, in terms of numbers of families, in the wet season 2004, with a mean number of 16.5 (± 4.23 SD), 12.2 (± 5.04 SD) and 13.3 (± 3.8) respectively, and, in terms of numbers of genera, the highest diversity in the wet season was also recorded at those sites with a mean number of 17.2 (± 3.97 SD), 12.8 (± 5.71 SD) and 13.3 (± 3.8) genera station-1 respectively.

Overall, the majority (68.7%) of infaunal organisms recorded during the wet season were from the Phyla Annelida. The remainder were Arthropoda (15.0%), Echinodermata (7.2%), Mollusca (4.9%), Sipuncula (3.9%), Echiura (0.2%) and Platyhelminthes (0.1%).

The polychaete worm Prionospio queenslandica from the family Spionidae, was the most abundant species from the wet season surveys. This species was recorded in highest numbers at the Black Point (BP1 and BP2) and Adamasta Channel (AC) sites. No rare or uncommon species of infauna were recorded at South Soko or along the proposed pipeline alignment. Details on a notable epifaunal species, the amphioxus Branchiostoma belcheri, found at SK3 in the wet season, are given at the end of this results section.

The composition of infaunal organisms (grouped by class) at each site in terms of mean number of individuals recorded during the wet season 2004 and 2005 surveys, is presented in Figure 9.16. At most sites, the Polychaeta marine worms were the dominant group in terms of mean number of individuals recorded. At Urmston Road (UR) and South Soko SK3 sites, much higher numbers of clams (from the class Bivalva) were found.

The composition of infauna at each site in terms of mean biomass grouped at class level is presented in Figure 9.17. Although animals such as the Polychaeta tended to be most numerically abundant, the larger-bodied animals from the Bivalva and Echinoidea groups made large contributions to biomass at sites such as Black Point (BP1 and BP2), Urmston Road (UR) and south South Soko (SSK3).

Figure 9.16 Mean numbers of Individuals per Station of Infaunal Organisms (Class level) from Benthic Samples collected at South Soko Island and along the Preliminary Submarine Pipeline Corridor during the Wet Season Surveys

Figure 9.17 Mean Biomass station-1 Infaunal Organisms (Class level) from Benthic Samples collected at South Soko Island and along the Preliminary Submarine Pipeline Corridor during the Wet Season Surveys

Amphioxus

Besides infaunal organisms, grab samples contained some epifauna that live close to or on the surface of the seabed. Among these, there was a notable record of the amphioxus species Branchiostoma belcheri found at the eastern facing bay, Tung Wan (Site SK3). In China, where it was an important fishery resource, it is listed as a Class II protected species due to over-exploitation. In Hong Kong, Branchiostoma belcheri is considered to be a species of conservation interest. During the 2004 dry season survey, a total of 36 individuals of this species were recorded with the majority found in a single grab sample from one sampling station (SK3-1: 34 individuals, SK-3-3: 1 individual, SK3-5: 1 individual). These animals were also recorded from this site in the 2004 wet season with a total of 13 individuals present in the samples (SK3-1: 10 individuals, SK-3-2: 2 individuals, SK3-6: 1 individual).

Branchiostoma belcheri is mobile animal that can freely swim through the water but typically burrows in sand during feeding. Although there are few publications on this eel-like animal’s ecology, in terms of habitat preference, it has been reported that it prefers sandy seabed areas with a depth of - 8 to 15 m which have comparatively clear and saline waters ([59]). The species has a wide distribution and been recorded around the region including China, Taiwan, Japan, Phillipines, Thailand, Northern Australia as well as further a field in India, Madagascar and East Africa. It was recently recorded from several sampling sites across eastern Hong Kong waters from Tai Long Wan, Long Ke Wan, Sai Kung to Ninepins and the Tathong Channel ([60]). Except at Tai Long Wan, only one or two individuals were recorded from these locations. ERM also reported this species off Big Wave Bay, Hong Kong Island with 72 individuals recorded ([61]). In the past, this species was also regularly recorded in Starfish Bay, Tolo Harbour ([62]) . In Hong Kong, Branchiostoma belcheri is considered to have a restricted distribution, which means populations are mainly concentrated in specific coastal areas.

The site with the highest abundance of this species in Hong Kong is Tai Long Wan in the northeast New Territories. At Tai Long Wan, Branchiostoma was reported as highly abundant with densities recorded at 98 m-2 and 102 m-2. In comparison to Tai Long Wan, it appears that site SK3 at Tung Wan, on the east side of South Soko, supports a low abundance of Branchiostoma. The density of Branchiostoma at this site was 10.4 ( 23.8 m-2 in the dry season and 3.8 ( 6.8 m-2 in the wet season.

9.3.13 Comparison of South Soko Benthic Fauna With Other Sites in Hong Kong

A comparison with similar sites in Hong Kong puts the ecological value of the study site in perspective with the ecology of the surrounding area and also other sites that may share the same physical attributes such as outlying islands around Hong Kong. Sources of information that were used in compiling this comparative data were the Seabed Ecology studies conducted by ERM ([63]), the study on marine benthic communities conducted by City U Professional Services Ltd ([64]) along with other EIAs and reports conducted by ERM.

As can be seen from Figure 9.18 the benthic biomass of comparable areas in Hong Kong varies greatly including across seasons. Compared with previous surveys’ results, the dry season biomass recorded during the present study at South Soko and Western Lantau was generally higher than other areas except Hei Ling Chau. In contrast, dry season biomass recorded near Lung Kwu Chau and Sha Chau was generally lower than other areas.

The biomass of the infaunal communities found at South Soko during the present study was higher than most of the other previously studied areas but lower than that of Hei Ling Chau, which had a mean biomass of 174 g m-2. The biomass of benthic communities recorded at Western Lantau and off Lung Kwu Chau and Shau Chau during the wet season was similar to most other areas.

Figure 9.18 Comparison of Mean Biomass of Benthic communities around Hong Kong (Source: +Present Study, *City U 2002 ([65]), °ERM 1998 ([66]) and #ERM 2000b ([67]))

The species diversity of the benthic community along the corridor of the proposed submarine natural gas pipeline (AC, PH, TO, MP1, MP2, UR, BP1 and BP2) was similar to most locations in Hong Kong ([68]). The number of species of the benthic organisms along the corridor of the proposed submarine natural gas pipeline were recorded in the range of 15 to 33 species per 0.576 m2 during wet season and 19 to 35 species per 0.576 m2 during dry season. In comparison, the mean number of species of the 120 stations surveyed by CityU ([69]) were 32.9 per 0.5 m2 (wet season) and 33.7 per 0.5 m2 (dry season) respectively.

The species diversity of the benthic community at the proposed LNG terminal (reclamation sites SK1 and SK3, and turning circle and approach channel SSK1, SSK2 and SSK4) was comparatively higher than the Hong Kong average. The number of species at the sites was in the range 30 to 53 species per 0.576 m2 during dry season and 29 to 52 species per 0.576 m2 during the wet season.

9.3.14 Marine Mammals

Methodology

Land-based Visual Survey

Land-based visual surveys were conducted in the study area to qualitatively estimate marine mammal use of habitats in the vicinity of South Soko. As stated previously, the land-based surveys were conducted to closely focus on the nearshore waters in the vicinity of the proposed LNG terminal and to provide additional information to supplement vessel-based survey findings. The observation site was a fixed concrete platform located on the north headland of South Soko approximately 60 metres above sea level. An overview of the existing environment around the observation site is presented and shown in Figure 9.19. The selected Observation Site was the same site used for the ongoing marine mammal research commissioned by the AFCD. It should be noted that some of the sighting areas, including the proposed jetty location, are blocked by the land mass, but the proposed reclamation sites (Tung Wan and Sai Wan) of the LNG terminal can be observed clearly from the observation site (Figure 9.19).

During the survey period, one of the paired observers scanned the survey area continuously with Olympus 10 x 42 hand-held marine binoculars while the other used naked eye and occasional binocular scans to identify, estimate group size, and study behaviour of the any marine mammals observed in the study area. The role of observers rotated every 30 minutes. Each survey was 6 hours in length. Survey times shifted to record marine mammal activity during all possible daylight hours during the survey period.

Monitoring surveys were conducted for five days of each month. Surveys were conducted monthly, commencing in February 2004, and lasting for a full calendar year up to the end of January 2005.

Data Collected

The locations of all marine mammals sighted within 2km of the sighting point were recorded on a data sheet (Table 16 of Annex 9-A). The species and number of marine mammals, number of sightings and travelling paths were recorded, together with observed behaviours at the times of sightings. Whenever possible, the colour and spot pattern was also recorded. Due to the distances involved, the age classes recorded during land-based visual survey can only be classified as juvenile (unspotted calf or unspotted juvenile) or adult (mottled, speckled, spotted adult and unspotted adult). If fifteen minutes had passed with no sightings after an initial sighting was made, any observed marine mammals were then considered to be a new group or individual. As such, the "sighting" data recorded represents first count data, or the location where the marine mammals were first observed.

Distinguishing Features

The distinguishing features of the two marine mammals observed during the surveys are as follows:

· Indo-Pacific Humpback Dolphin (Sousa chinensis) - Sousa chinensis is distinguished by its wide-based, slightly falcate dorsal fin, located at mid-back. They have a long, slender rostrum, with a shallow groove between the melon and the beak. Adults are up to 2.8 m long and are white to pink in colour, and often have a variable degree of black spotting or mottling.

· Finless Porpoise (Neophocaena phocaenoides) - Neophocaena phocaenoides is characterized by its lack of dorsal fin and the presence of a dorsal ridge. It also has no beak. It is smaller in size than humpback dolphins with an average body length of much less than 2 metres. Adults are commonly dark grey to black in colour.

Age Classes

Age class of humpback dolphins was identified in accordance with the six age classes defined by Jefferson (Jefferson 2000) ([70]). The classification of their age class was mainly based on their body size and length, skin colouring pattern, and density of spotting. Their skin colour pattern changes dramatically throughout their lifespan, whitening increases as age increases. The spot patterns on juveniles and subadults disappear gradually as they get older, as presented in Table 9.16Table 9.16.

Table 9.16 Age Classes of Sousa chinensis

Age Class	Body Length (m)	Colour Pattern	Spotted Pattern	Behaviour
Unspotted Calf (UC)	1 m to 1.3 m (approximately half length of adults); up to 6-8 months of age	Uniform black to dark grey	No spots	Swim dependently of adult, presumably the mother
Unspotted Juvenile (UJ)	Approximately 1.5 m to 2 m (two-third of the adult length)	Uniform light grey	No spots	Occur in the vicinity of adults.
Mottled (MO)	Approximately similar length as SAs and UAs; 8.5 to 9 years old	Light pinkish grey	Heaving spotting	Same as SAs and UAs
Speckled (SP)	With same size as SAs and UAs	Pale pink to white	Less spotting pattern than MO	Full independence of movement and association; hard to distinguish from SA.
Spotted Adult (SA)	Same as UA	Purely pink to white	Less spotting pattern than MO or SP	Same as SP
Unspotted Adult (UA)	Up to 2.6 m	Purely pink to white	Essentially no spotting pattern but may have a few tiny spots	Same as SAs and SPs

Only three classes, adult (include MO, SP, SA and UA), juvenile (UJ) and calf (UC), can be identified during the land-based visual survey due to the distant observation.

Age-determination study for finless porpoise has been undertaken by tooth aging method, however, it cannot be applied in the field ([71]). Growth of finless porpoise can be classified into a number of age/sex classes ([72]). Neonates can be distinguished by relatively large flippers, a shallow forehead, lighter colour than adults, a very light patch around the lips and a gape-to-flipper stripe ([73]). Very young newborns may still show prominent fetal folds. Meanwhile, light grey skill colour with steeper forehead and prominent light lip patch are still observed in juvenile stage ([74]). Adults are dark grey in colour.

Behaviour

Marine mammals exhibit certain behaviours and for humpback dolphins this has been previously characterised ([75]) ([76]). These are presented in (Table 9.17Table 9.17).

Table 9.17 A Summary and Description of Specific Types of Behaviour and Activities exhibited by Indo-Pacific Humpback Dolphin Sousa chinensis

Type of Social Behaviours and Activities		Descriptions
Activities
Free Travelling		Directional motion, Swimming fast, taking regular breaths on water surface.
Feeding/Foraging		Long jumping and high-speed chasing while hunting fish; On sea surface, swimming slowly rising intermittently before commencing the next dive. They may display certain behaviours such as feeding rushes, fish whacking, carousels, and fluking dives.
Boat chasing/ Feeding behind trawlers		Following behind trawlers as a sign of feeding, they catch fish through the net or escaping from it.
Milling/Resting		Remaining in one area without any sign of feeding or social interaction; move slowly with a drifting or gliding motion, rising slowly, or breathing while circling over the same area.
Socializing	Extensive bodily contact, inverted swimming, somersaulting, leaping and chasing with aerial activity; group activities centred on animate or inanimate objects; two to three individuals form a group.
Spot Behaviour
Breaching	A behavioural pattern also known as body slamming or a ‘log’ jump. The animal rises out of the water at an angle between 90( to 45( to the sea surface. When exiting the water the dolphin’s flippers, its abdomen or peduncle may clear the surface.
Spyhopping	Raising the head vertically out of the water, then sinking below the water without a splash. Used to check an area for hazards.
Tail slapping	The act of slapping the tail against the sea surface.
Porpoising	Fast, shallow, arching leaps with the dolphin coming either partially or entirely out of the water. It was only observed when the dolphins were boat chasing and allows the animals to combine shallow dives for fish with a fast rate of travel. The adults will show noticeable colour changes, turning from white to a deep pink. This is probably due to vascular dilation in the blubber layer and is, possibly, a flush response to prevent overheating.
Nursing	An act of nursing a calf by a mother.

Studies on behaviour of finless porpoise are limited. Sightings are commonly less prominent as the porpoise only bring their heads and their dorsal surface above the water to breathe and the lack of dorsal fins makes them harder to spot. Observed porpoise behaviour is commonly simply feeding behaviour, such as “feeding circles” ([77]). Other feeding behaviours such as feeding rushes with a sudden acceleration directly towards prey and fish chasing are also common. Other observed behaviour is similar to that observed in humpback dolphins, such as travelling and milling (refer to Table 9.17Table 9.17).

Site and Weather Conditions

Site conditions including sea state, weather and visibility were also recorded along with any changes in environmental conditions if they occurred during the duration of a survey. Surveys were only conducted under acceptable sighting and weather conditions. Acceptable sighting conditions were defined as days with sea state conditions of Beaufort 0 – 5, and visibility of at least 2km from the observation point. No surveys were conducted during unacceptable weather conditions, such as during low visibility or during typhoons, thunderstorms or heavy rainstorm warnings reported by the Hong Kong Observatory.

Vessel Based Visual Survey

General Approach and Survey Subareas

Surveys were conducted in four subareas. General characteristics of the four survey subareas are listed in Table 9.18Table 9.18. Southwest Lantau (66 km2) represents a new stratification of the South Lantau survey area, and this is the western portion that includes the Fan Lau and the South Soko Island area. West Lantau (28 km2) is the narrow strip along the western part of Lantau Island, and it would represent part of the pipeline route. Northwest Lantau (38 km2) is a narrow strip along the western border of Hong Kong, and it includes waters of the Sha Chau and Lung Kwu Chau Marine Park. The survey area for this project represents only the western portion of the Northwest Lantau area of the long-term study ([78]) ([79]) and is part of the pipeline route.

Table 9.18 Summary of Characteristics of the Four Survey Subareas in Hong Kong

Survey Area	Area (km2)	Effort (km) (1)	Description
Deep Bay (DB)	30 (2)	1,679	Very shallow enclosed bay with extensive mudflats and mangroves; influenced by the Pearl River (high turbidity)
Northwest Lantau (NWL)	38	530	Strong influence from Pearl River; location of Sha Chau/Lung Kwu Chau Marine Park; Urmston Road shipping channel goes through north end
West Lantau (WL)	28	3,094	Strong influence from Pearl River; narrow strip along western border of Hong Kong; light development; dolphin watching vessels at Tai O
Southwest Lantau (SWL)	66	5,498	Seasonally influenced by the Pearl River; very little development, but includes major ferry lanes to Macau

Note: (1) Total survey effort conducted during this study is presented here, but the survey effort (L) presented in Table 9.19 is only that used in calculation of the abundance estimates (i.e., Beaufort 0-3 data).

(2) The total area of Deep Bay is about 97 km2, but the portion that is within the Hong Kong SAR boundary is 60 km2. However, only half of this area could be surveyed, due to the northern portion of the bay being too shallow for the vessel to operate. Thus, abundance was only estimated for the surveyed area of 30 km2.

The Deep Bay subarea contains the Black Point site at its southern boundary. Deep Bay itself is actually about 97 km2, but it is bisected by the Hong Kong SAR/Guangdong boundary. The portion that occurs within the Hong Kong SAR is only 60 km2. However, the northern portion of Deep Bay is very shallow, with mud flats often exposed at low tides. Due to this fact, as well as the confounding presence of the Crosslinks Bridge (Deep Bay Link) and several oyster rafts, survey vessel were unable to safely navigate into the northern portion of Deep Bay. As a consequence, the vessel-based surveys were conducted only in the southern portion of Deep Bay (30 km2).

The seasons were defined as follows: Winter (December-February), Spring (March-May), Summer (June-August), and Autumn (September-November). This is the same as in the long-term study.

The survey transect lines were presented in Figure 9.20.

Survey Methods

Vessel surveys were conducted from two survey vessels, the King Dragon and the Tsun Wing (both ca. 12-15 m length, with similar configuration), weather permitting (Beaufort 0-6, no heavy rain, and visibility > 1,200 m). However, only data collected in calm conditions of Beaufort 0-3 are useable in calculating line transect estimates of density and abundance ([80]) ([81]). The vessel had an open upper deck, affording relatively unrestricted visibility. The observer team conducted searches and observations from the flying bridge area, 4-5 m eye height above the water's surface. Two observers made up the on-effort survey team. As the vessel transited the survey lines at a relatively constant speed of approximately 15 km/hr, the primary observer searched for dolphins and porpoises continuously through 7 X 50 Brunton marine binoculars. The data recorder searched with unaided eye and filled-out the data sheets. Both observers searched ahead of the vessel, between 270° and 90° (in relation to the bow, which is defined as 0°). On most surveys, there were three observers, and one auditor.

Observers rotated positions after approximately 30 minutes of effort, to give them a rest after each hour of search effort, thereby minimizing fatigue. Observers had undergone a 3-day training program before the start of data collection, which included detailed classroom instruction and a day of at-sea training. Only two species of small cetaceans regularly occur in Hong Kong, the humpback dolphin and finless porpoise ([82]) ([83]). These two species are radically different in appearance and behaviour, and so all sightings (even those seen briefly or from a distance) could be identified to species.

Effort data collected during on-effort survey periods included time and position for the start and end of search effort, vessel speed, sea state (Beaufort scale), visibility, and distance travelled in each series (a continuous period of search effort). When dolphins or porpoises were sighted, the data recorder filled out a sighting sheet, and generally the team was taken off-effort and the vessel diverted from its course to approach the dolphin group for group size estimation, assessment of group composition, behavioural observations, and collection of identification photos. The sighting sheet included information on initial sighting angle and distance, position of initial sighting, sea state, group size and composition, and behaviour, such as response to the survey vessel and associations with fishing vessels (Tables 18 and 19 of Annex 9-A). Position, distance travelled, and vessel speed were obtained from a hand-held Global Positioning System (a Garmin Gecko GPS unit).

Observers were trained and calibrated in distance estimation, by asking them to make distance estimates to various objects (e.g., other boats, specific points on shore, floating debris, etc.). Simultaneously, a distance reading was taken with a laser rangefinder (Leica 800 or Bushnell Yardage Pro 800 model). Plots of measured vs. estimated distance were shown to observers occasionally, so they could see if they needed to refine their distance estimates. This procedure resulted in increased accuracy of observer distance estimates, and previous efforts have shown that significant bias is not caused by the remaining inaccuracy in distance estimation ([84])([85])([86]).

When dolphins were sighted, the observers typically went off-effort and the vessel approached the dolphin group for accurate estimation of group size/composition and for photo-identification. Photographs were taken with Canon 35-mm SLR autofocus cameras (EOS 20D digital model). Cameras were equipped with digital data recorders and date and time were associated with each frame, allowing it to be correlated with a particular sighting. The primary lens used was a Canon L series 300 mm / f4.0 image stabilizer telephoto. Usually, the lens was used with a 1.4X teleconverter, thereby increasing its effective focal length. Images were shot at the highest available resolution (8.2 megapixels) and stored on Compact Flash cards (mostly 1.0 GB).

For photo-identification, generally, dolphin groups were approached slowly from the side and behind ([87]). Manoeuvring the boat to within 15-40 m, directly alongside a moving group of dolphins resulted in the best shots. Every attempt was made to photograph each dolphin in the group, even those that appeared to have no unique markings. If possible, both sides of the dolphins were photographed, since the coloration markings are not completely symmetrical.

Data Analysis Methods

Line Transect Analysis

One day’s survey effort was used as the sample for analyses. For estimation of density and abundance, only surveys with at least 2.0 km of useable effort were included. Estimates were calculated from sighting and effort data collected during conditions of Beaufort 0-3 ([88])([89])([90]), using line transect methods ([91]). The estimates were made using the computer program DISTANCE Version 2.2 ([92]). The following formulae were used to estimate density, abundance, and their associated coefficient of variation:

where D = density (of individuals),

n = number of on-effort sightings,

f(0) = trackline probability density at zero distance,

E(s) = unbiased estimate of average group size,

L = length of transect lines surveyed on effort,

g(0) = trackline detection probability,

N = abundance,

A = size of the survey area,

CV = coefficient of variation, and

var = variance.

For the Northwest Lantau area, because the current study did not survey the entire survey area used in the long-term study, individual encounter rates for each season were calculated as a basis for comparison. This is largely equivalent to calculating densities, but it does not explicitly take into account variations in sightability of the dolphins. However, despite this, it provides a useful basis for comparison with future surveys. The encounter rates were calculated by dividing the number of individual dolphins observed on a particular day by the amount of effort conducted on that day. Seasonal averages and their standard deviations were then computed. Only data collected during Beaufort 0-3 conditions were used for this.

Pooling and Stratification Strategies

A strategy of selective pooling and stratification was used, in order to minimize bias and maximize precision in making the estimates of density and abundance ([93]). Data from the long-term database (most research funded by AFCD) were pooled with data from the present study to increase sample sizes and improve the robustness of the analyses. This strategy can be applied directly to the Deep Bay, Southwest Lantau and West Lantau areas. It involved post stratification of the long-term data from South Lantau into Southeast and Southwest Lantau areas to allow the pooling of long-term data from Southwest Lantau with data from the LNG study. The Northwest Lantau area of the current study was defined specifically for this project, and this subarea was not used in the long-term study. Different strategies were used for various line transect components, and these are described below:

Sighting Rate [n/L] - Sighting rate varies strongly with season and area ([94])([95]), and thus a fully-stratified analysis (full stratification by both season and survey area) was used. Clearly, sighting rate is one of the major parameters affecting density and abundance estimates, and although sample sizes were small for some strata (n < 5), pooling was not justified.

Trackline Probability Density [f(0)] - Because biases associated with small sample sizes can strongly affect the accuracy of density and abundance estimates, Buckland et al.'s (2001) ([96]) guidelines regarding minimal sample sizes for estimation of the trackline probability density were followed. They suggested a minimum sample size of 60 sightings for modeling of this parameter. Several mathematical models were fitted to the data (hazard-rate, half-normal, and uniform), and the model with the lowest value of the Akaike’s Information Criterion was automatically chosen by DISTANCE for estimation of f(0). Because most seasons within a phase did not have adequate numbers of sightings, all the data (from all four seasons and the three main survey subareas) were pooled to calculate a single humpback dolphin trackline probability density, and then used this in all the estimates of density and abundance. This strategy ensured sample sizes of > 100 for humpback dolphins.

For finless porpoises, although only 29 sightings were made in the LNG study, the post-stratification of the South Lantau long-term data into Southeast and Southwest Lantau (see above) allowed the LNG and long-term data to be pooled together, thereby achieving a sample size of more than 60 for this species.

Average Group Size [E(s)] - Because of indications that group size varies by geographic region and season ([97])([98]), a fully-stratified analysis was used. DISTANCE computed both the arithmetic mean and a size-bias corrected mean; the lesser of these two values was used in the calculations (in order to avoid size-bias generally caused by missing smaller groups at large perpendicular distances).

Trackline Detection Probability [g(0)] - For Hong Kong humpback dolphins, Jefferson (2000) ([99]) reported group dive time data and collected 71.8 hours of independent observer data, and from this estimated that the detection probability is unity for that study. The present study was an extension of Jefferson's (2000) ([100]), with all survey techniques held constant. Therefore the previously estimated value of g(0) = 1.0 was used for all density and abundance calculations.

For finless porpoises, the estimate of g(0) presented by Jefferson et al. (2002) ([101]), which was calculated from data collected with a Porpoise Detector (POD), was used. This device collects data on the occurrence of acoustic clicks made by porpoises. The value of the estimate was 0.72.

Coefficient of Variation [CV] – The variance component for the appropriate estimate of each component of the line transect equation was used in calculating the overall CV of the estimated density and abundance (see formula above). This resulted in more precise estimates for some areas and seasons than would have been the case with a fully-stratified analysis. However, this came at the expense of some slight potential for increase in bias.

Photo-identification and Age Class Composition

Photographs of dolphins taken during surveys were first examined and sorted into those that contained a potentially identifiable individual. Then, those photos were again examined in detail and any identifiable individuals were compared to the photo-ID catalog accumulated over the last 10+ years of dolphin research in Hong Kong and the Pearl River Estuary. Any new individuals were given a new identification number and their data were added to the catalog. Most of the analyses used data from the long-term database. Photo-identification is not possible with finless porpoises.

Observers attempted to classify the dolphins observed into the six age classes identified in the long-term study on humpback dolphins in Hong Kong (see Table 9.16Table 9.16). However, many animals were not seen at close enough range to place them into an age class, and therefore only data on groups from which the age class composition of the entire group was determined was analyzed.

Grid Analysis of Habitat Use

For the quantitative grid analysis of habitat use of humpback dolphins and finless porpoises, positions of on-effort sightings were plotted onto 1 km2 grids within the four survey subareas. Sighting densities (number of on-effort sightings per km2) were calculated for each grid. Sighting density grids were then further normalized with the amount of survey effort conducted within each grid. The survey effort spent in each grid for each survey day was examined in detail (i.e., when the survey boat traversed through a specific grid once, one unit of survey effort was counted for that grid), and then the amount of survey effort per grid was calculated for all sighting density grids. After normalizing the original sighting density grids by survey effort, sighting density data were generated. The new density unit is termed “SPSE”, representing the number of on-effort sightings per unit of survey effort. This sighting density information, was further elaborated to look at actual dolphin / porpoise densities (exact number of dolphins or porpoises from on-effort sightings per km2). The new unit was termed “DPSE”, which is the number of individual dolphins / porpoises per unit of survey effort. Plotting the DPSE values of surveyed grid squares on maps allows areas where the most dense sightings of dolphins and porpoises occur to be identified.

Ranging Pattern Analysis

Location data were obtained from the long-term sighting database and photoidentification catalog, and only those individuals sighted ten times or more were included for analysis of individual home ranges ([102]). A desktop GIS (ArcView© 3.1) with the Animal Movement Extension was used to examine individual ranging patterns. Using the Animal Movement Extension for ArcView©, a polygon joining the outermost sighting positions was formed, indicating the area used by an individual dolphin during the long-term study period. Range dimensions of the dolphin were then calculated by GIS with land masses excluded.

Behavioural Data Analysis

When dolphins were sighted during vessel surveys, their behaviours were recorded through direct observations and by digital video system. Different activities were categorized (i.e., feeding, milling/resting, traveling, socializing) and recorded on the sighting datasheets, and the dolphin behaviours were taped by a digital video recorder. These data were input into a separate database with sighting information, which was then used to determine the distribution of behaviours with desktop GIS.

Survey Results

Land-based Visual Survey

Seasonal Records

During February 2004 to January 2005, there were a total of 65 marine mammal surveys undertaken (a total of 360 hours). Over this period, two residential marine mammals Indo-Pacific Humpback Dolphin Sousa chinensis and Finless Porpoise Neophocaena phocaenoides were observed and recorded at South Soko. There were 24 sighting records of humpback dolphins (52 individuals), and 5 sighting records of finless porpoise (13 individuals) reported during the surveys. Seasonal records of marine mammal sightings are presented in Table 17 of Annex 9-A. The locations of sightings were plotted in relation to season, and are presented in Figure 9.21 ([103]) .

Humpback dolphins were recorded in all four seasons and most sightings were recorded in waters around Lan Nai Wan, the sea channel between North and South Sokos, and outer Tung Wan. Finless porpoises were only found in spring and winter in Sai Wan, Pak Tso Wan and the sea channel between North and South Sokos.

Number of sightings and number of individuals of marine mammals are presented in Figures 9.22 & 9.23. The data presented in these figures have not been corrected for effort and are raw sightings data.

Figure 9.22 Number of Sightings and Individuals of Indo-Pacific Humpback Dolphin Sousa chinensis at South Soko (Data collected from February 2004 to January 2005) from land based surveys

No sighting

No sighting

Figure 9.23 Number of Sightings and Individuals of Finless Porpoise Neophocaena phocaenoides at South Soko (Data collected from February 2004 to January 2005) from land based surveys

Note: (1) These data provide supplementary information to check on habitat use in the immediate vicinity of the proposed works but were not relied upon for characterisation of dolphin abundance or seasonal distribution in these waters. Instead, vessel-based survey results (both LNG surveys and long-term data) (presented below) for the same waters and across Southwest Lantau provided the scientific basis for quantifying seasonal abundance of marine mammals for assessment purposes.

From the land based surveys, both marine mammal species exhibited a seasonal pattern at South Soko. The majority of humpback dolphins and finless porpoises were recorded in spring and in winter. For the humpback dolphins, there were 9 sightings (16 individuals) recorded in spring and 4 sightings (13 individuals) recorded in winter (Figures 9.22 & 9.23). For finless porpoise, there were 3 sightings (6 individuals) recorded in spring and 2 sightings (7 individuals) recorded in winter (Figures 9.22 & 9.23).

It is important to note, owing to the small sample size of the land-based survey dataset, quantitative comparisons of seasonal abundance with extensive data collected from vessel-based survey are of limited value. Nevertheless, the usefulness of the land-based surveys is demonstrated by the fact that dolphins were observed in the immediate vicinity of South Soko in spring whereas there have been no sightings of dolphins close to the Soko Islands by vessel-based surveys. Owing to the difference in survey methods and survey times, such differences are not unexpected. Even though vessel-based survey may not record dolphins in certain areas, this does not mean dolphins never occur in those areas.

Marine Mammal Age Class

The majority of humpback dolphins recorded during the land-based surveys were identified as Adults (50 individuals). Juveniles (2 individuals) were also recorded, as presented in Table 17 of Annex 9-A and Figure 9.20. Neophocaena phocaenoides were all adults, except for one juvenile recorded (Table 17 of Annex 9-A).

Vessel Based Visual Survey

Data Collected

In the 11 month study period (July 2005 to May 2006), 70 days of surveys have been conducted. During this time, a total of 5,045 km of transect lines have been surveyed. Among the 5,045 km surveyed transect lines, 4,097 km (81%) of the total were conducted during relatively calm sea conditions of Beaufort 0-3, and therefore were useable in the estimation of density and abundance. Of the effort conducted in Beaufort 0-3 conditions, 2,409 km was in Southwest Lantau, 396 km was in West Lantau, 385 km was in Northwest Lantau, and 906 km was in Deep Bay.

There were a total of 275 sightings of Indo-Pacific Humpback Dolphins Sousa chinensis. Most sightings took place in West Lantau (n = 109) and Southwest Lantau (n = 79), with fewer sightings from Northwest Lantau (n = 62), and the fewest in Deep Bay (n = 25). The dolphin sightings were relatively evenly-distributed among most seasons: Summer (n = 66), Autumn (n = 88), Winter (n = 82), but only 39 were obtained in spring.

Finless porpoise sightings numbered 29 in total, and all of these occurred in Southwest Lantau. Most took place in winter and spring months (n = 13 in each season), with only one in summer and two in autumn.

Distribution

It is important to recognize that, due to differential survey effort in various survey subareas, it is not possible to compare densities of dolphins or porpoises by examining maps of distribution. The distribution maps are only useful for determining where animals do and do not occur, and for comparing use of the area on a small scale (within a survey subarea). Comparisons of density or habitat use on a larger scale should make use of numerical density estimates or the results of the grid analyses (discuss below).

Dolphins were observed throughout all of the surveyed areas, and sightings occurred in most areas, except directly south of the Sha Chau/ Lung Kwu Chau Marine Park and at the very northern end of the Deep Bay survey area (Figure 9.20). The areas of both potential sites for the LNG terminal are used by dolphins in all seasons covered in this report. To date, there appear to be no strong seasonal differences in distribution of dolphins among the different survey subareas, except there are fewer dolphins around in the spring months (Figures 9.24 - 9.27).

The distribution of young dolphins (Unspotted Calves and Unspotted Juveniles) (Figures 9.28 - 9.31) indicated that they were concentrated in four areas: (1) southern Deep Bay, (2) around Lung Kwu Chau, (3) all along the West Lantau coastline, and (4) in Southwest Lantau between Fan Lau and the Soko Island. The composition of young animals in Deep Bay differed from the other areas owing to the much lower number of Unspotted Calves sighted in this area. It can be noted that the latest analysis of calving seasonality based on methods for determining the age of stranded calves and hence their time of birth, indicates that most (76%) calving occurs in a six month period between March and August ([104]). Within this six month period, the highest calving frequency occurs in the months of May and June. It is noted that calving also occurs in all other months but at comparatively lower levels.

The distribution of dolphins engaged in feeding and socializing behaviours are shown in Figures 9.32 - 9.35, respectively. These will be discussed in more detail under the Behaviour section below.

As expected, finless porpoises were only observed in the Southwest Lantau subarea, and most of the sightings were in the winter and spring months (Figure 9.36). Finless porpoise groups occurred around the Soko Islands, mainly within 2 km of the islands, but not near shore. The overlap of distribution between finless porpoises and dolphins in the Southwest Lantau area is shown in Figure 9.37.

Abundance and Density

Survey effort corrected estimates of density and abundance, and their associated parameters are presented for Deep Bay, West Lantau, and Southwest Lantau in Table 9.19Table 9.19. For humpback dolphins, Deep Bay had low densities (0.08-0.23 dolphins km-2) and low estimates of abundance (<10 dolphins in all seasons). It is clear that dolphins use the mouth of Deep Bay at a low level throughout the year. West Lantau had high humpback dolphin densities (1.71-2.81 dolphins km-2) and relatively high abundances (47-78) of dolphins (for such a small area) in all seasons. Dolphins are sighted in this area in all seasons. Southwest Lantau had lower levels of dolphin density (0.10-0.44 dolphins km-2) and abundance (6-29 dolphins) than West Lantau, but higher than Deep Bay. Dolphins are sighted in this area in three seasons, but clearly it is used much less heavily in spring months. Northwest Lantau also had lower levels of dolphin density (0.57-0.94), but similar abundance (49-82) compared to West Lantau. Northwest Lantau had higher levels of dolphin density and abundance than Deep Bay and Southwest Lantau. Dolphins were sighted in Northwest Lantau in all seasons, but less so in spring.

Table 9.19 Estimates of Abundance and Associated Parameters for Humpback Dolphins and Finless Porpoises in the Three Survey Subareas (NWL is also discussed in the text), and other Subareas for Comparison

Survey Area	Survey Days	L (km)	n	f(0) (km-1)	E (s)	D (km-2)	N	CV (%)
Indo-Pacific Humpback Dolphin Sousa chinensis
Deep Bay
Winter	19	314	11	4.7071	2.72	0.23	7	46
Spring	21	354	5	4.7071	4.80	0.16	5	55
Summer	21	376	5	4.7071	2.60	0.08	2	49
Autumn	20	374	9	4.7071	4.11	0.23	7	42
Northwest Lantau
Winter	36	1,051	107	3.6502	3.90	0.73	63	17
Spring	36	1,059	93	3.6502	3.51	0.57	49	17
Summer	38	1,084	113	3.6502	3.78	0.72	63	15
Autumn	38	1,229	152	3.6502	4.16	0.94	82	12
West Lantau
Winter	29	448	107	4.7071	4.94	2.78	77	18
Spring	28	401	92	4.7071	3.17	1.71	47	20
Summer	29	473	128	4.7071	3.84	2.45	68	18
Autumn	34	550	137	4.7071	4.80	2.81	78	18
Southwest Lantau
Winter	44	1136	48	4.7071	3.10	0.31	20	20
Spring	37	1051	8	4.7071	5.38	0.10	6	44
Summer	38	1374	47	4.7071	3.47	0.28	18	27
Autumn	31	908	37	4.7071	4.57	0.44	29	27
Finless porpoise Neophocaena phocaenoides
Southwest Lantau
Winter	44	1136	22	5.2054	1.9	0.09	8	35
Spring	37	1051	26	5.2054	2.6	0.17	15	39
Summer	38	1374	1	5.2054	1.0	< 0.01	0	78
Autumn	31	908	2	5.2054	1.5	0.01	1	67
Lamma(4)
Winter	-	1173	17	6.10	2.4	0.10	17	32
Spring	-	1126	35	3.75	5.9	0.52	90	32
Summer	-	1007	4	3.75	2.0	0.02	4	50
Autumn	-	1283	12	3.84	1.6	0.04	7	32
Po Toi(4)
Winter	-	400	6	7.68	1.3	0.07	14	63
Spring	-	962	3	79.47	1.7	0.02	4	60
Summer	-	940	18	5.50	2.8	0.17	32	36
Autumn	-	667	16	4.65	2.0	0.14	26	36

Note: (1) L=total length of transect surveyed; n=number of on-effort sightings; f(0)=trackline probability density; E(s)=unbiased mean group size; D= density of individuals; N=individual abundance; and CV=coefficient of variation.

(2) Only data collected in Beau 0-3 conditions are included here.

(3) As explained previously, the individual density value (D) represents an estimate of the number of individual dolphins / porpoises in a 1 km2 grid square area.

(4) Data extracted from Jefferson et al. 2002 ([105]) for comparative purposes. Note (3) is not applicable to this data.

Finless porpoises were only seen in Southwest Lantau, and estimates of abundance (0-15 porpoises) and density (0.002-0.167 porpoises km-2) were low for most seasons. However, spring season shows much higher densities and abundances of porpoises for this area, suggesting this at least a moderately important area for the species in Hong Kong during that season. According to the literature, other areas of Hong Kong such as key habitats at Lamma and Po Toi were found to support considerably higher densities (Lamma: 0.02 - 0.52 porpoises km-2, Po Toi; 0.02 - 0.17 porpoises km-2) and abundance (Lamma: 4 - 90 porpoises, Po Toi: 4 - 32 porpoises) of these animals (Table 9.19Table 9.19). However, based on the latest data, this situation may have changed as sightings were higher in the waters of the Po Toi Islands. In monitoring conducted in 2003 to 2005, finless porpoise sightings in South Lantau (12 sightings) were higher than in Lamma (2), Nine Pins (4) and Sai Kung (4), but lower than in Po Toi (15) ([106]) .

For the Northwest Lantau area, the seasonal estimates of average individual encounter rate (number of dolphin individuals recorded per survey effort) are shown in Table 9.20Table 9.20. Encounter rates increased from summer to autumn and then increased again from autumn to winter, finally decreasing dramatically in spring months.

Table 9.20 Individual Encounter Rate Information for Dolphins in Northwest Lantau (1) (Analysis Uses only Data Collected during Beaufort 0-3 Conditions)

Season	No. Surveys	Individuals	Encounter Rate	Std. Dev.
Summer	7	36	24.9	31.65
Autumn	6	53	46.5	20.62
Winter	3	65	166.3	52.58
Spring	6	18	17.1	20.93

Note: (1) This analysis uses only data collected by surveys for this EIA Study due to the unique designation of this survey subarea.

Long-term Trends in Abundance and Density

In order to investigate long-term trends in abundance of dolphins and porpoises in the survey subareas, data from the 1996-2006 line-transect dataset were used to calculate a time series of density and abundance estimates (Table 9.21). It should be noted that there were limitations on the temporal resolution attainable since it is necessary to maintain an adequate level of precision for the estimates (as indicated by lower CV values). As such, it was only possible to provide annual estimates for the West Lantau subarea. For other subareas, it was necessary to pool two or even three years of data.

Table 9.21 Trends in Estimates of Abundance and Associated Parameters for Humpback Dolphins and Finless Porpoises in the Three Survey Subareas

Survey Area	Survey Days	L (km)	n	f(0) (km-1)	E (s)	D (km-2)	N	CV (%)
Indo-Pacific Humpback Dolphin Sousa chinensis
Deep Bay
1997/98/99	22	514	10	4.7071	3.60	0.17	5	24
2005	35	543	7	4.7071	3.71	0.11	3	52
2006	24	360	13	4.7071	3.23	0.27	8	43
West Lantau
1997	6	67	9	4.7071	6.33	2.00	55	57
2002	10	108	39	4.7071	3.65	3.10	86	23
2003	43	661	175	4.7071	4.80	2.99	83	16
2004	39	641	160	4.7071	4.02	2.36	65	15
2005	57	1015	205	4.7071	3.88	1.84	51	10
2006	17	273	70	4.7071	4.64	2.80	77	19
Southwest Lantau
1997/98	23	444	16	4.7071	5.14	0.44	29	42
1999/00	20	430	13	4.7071	2.15	0.15	10	38
2001/02	23	448	22	4.7071	3.14	0.36	24	31
2003/04	20	536	23	4.7071	3.74	0.38	25	30
2005/06	64	2611	66	4.7071	3.85	0.23	15	21
Finless porpoise Neophocaena phocaenoides
Southwest Lantau
1997/98	11	230	8	5.2054	2.38	0.22	14	55
1999/00	10	196	4	5.2054	2.50	0.13	9	111
2001/02	13	235	8	5.2054	3.00	0.27	17	61
2003/04	12	328	4	5.2054	2.25	0.07	5	65
2005/06	35	1197	25	5.2054	2.08	0.11	7	30

Note: (1) L=total length of transect surveyed; n=number of on-effort sightings; f(0)=trackline probability density; E(s)=unbiased mean group size; D= density of individuals; N=individual abundance; and CV=coefficient of variation.

(2) Only data collected in Beau 0-3 conditions are included here.

(3) For 2006, estimates are incomplete, with only winter and spring data included.

(4) As explained previously, the density of individuals value (D) represents an estimate of the number of individual dolphins / porpoises in a 1 km2 grid square area.

Based on examination of estimates of dolphin density over time, it appears there are no consistent trends for any of the surveyed subareas. It should be borne in mind, a degree of caution is warranted in interpreting these figures to take account of the level of precision achievable. In general, in Deep Bay, it seems there was a decrease in past years and then an increase in humpback dolphins in the last year. In West Lantau, there was an increase, a decrease, and finally another increase. In Southwest Lantau, there was a decrease, followed by an increase, and another decrease. However the decrease in 2006 is considered to be an artefact of not including summer and autumn sightings data ([107]) when dolphin abundance is expected to be higher. For Finless Porpoises, abundance in Southwest Lantau decreased, then increased and then decreased. Overall, examination of estimates of dolphin density over time suggests that there have not been any dramatic changes in the abundance of dolphins or porpoises in the survey subareas over the last 10 years. The observed changes have generally been temporary short term fluctuations, not lasting more than a few years.

Grid Analysis of Habitat Use (July 2005 – May 2006)

Grid analysis of habitat use provides the best way to compare dolphin and porpoise use of specific areas, especially on a small scale. Because the data are standardized for differential survey effort, it is possible to compare density of two grids, even if they are in different survey subareas.

Using the line-transect survey data from the 11 month study, combined with AFCD data collected from the same period, survey effort data and dolphin/porpoise sighting data were retrieved to calculate DPSE values for 158 grids among the four study areas. The maps with density (DPSE) of humpback dolphins and finless porpoises with corrected survey effort per km2 of the four areas are shown in Figures 9.38 and 9.39 respectively.

The average DPSE values of the 158 grids for humpback dolphins in the four survey areas was 0.28 Among them, West Lantau represented the highest use area for dolphins, with an average DPSE value of 0.67. Moreover, West Lantau has the highest number of grids DPSE values >1. The western end of Northwest Lantau was also identified as an area with high dolphin usage, with average DPSE values 0.44. On the contrary, Southwest Lantau, in which South Soko forms part of the survey area, was moderately used by the dolphins, while Deep Bay was only used to a small extent ( Table 9.22Table 9.22).

Table 9.22 Average DPSE for Different Survey Subareas during the Study

	# grids	Ave. DPSE	# grids w/ DPSE>1
Deep Bay	26	0.06 ± 0.12	0
Northwest Lantau	28	0.44 ± 0.54	2
West Lantau	34	0.67 ± 0.51	10
Southwest Lantau	70	0.09 ± 0.13	0
Total	158	0.27 ± 0.42	2 (ave)

Habitat use of humpback dolphins was very uneven among the 1 km2 grids within the 4 areas. In Deep Bay, dolphin usage was higher toward the southwestern end of the survey area, and the highest densities occurred near the Black Point Power Station (Grids H5, I5 & J5). In Northwest Lantau, the dolphin usage was high around Lung Kwu Chau, especially at the eastern sides of the island (Grids G10 & H11). Dolphin densities were also high around the small island of Pak Chau (Grid G13). On the contrary, the southern portion of Northwest Lantau was much less heavily used by dolphins, especially the waters just west and northwest of the airport platform.

In West Lantau, dolphin usage was uniformly high all along the coastline. In particular, the waters between Sham Wat & Tai O (Grids D23, E22-23 & F22) and north to Peaked Hill (Grids B26-27 & C25-27) had relatively high dolphin usage. In Southwest Lantau, dolphin usage was relatively even throughout the survey area, with higher densities of dolphins near Fan Lau, Kau Ling Chung and around North Soko.

Grid Analysis of Habitat Use (Seasonal)

To examine the seasonal habitat use patterns of humpback dolphins and finless porpoises quantitatively in recent years, survey effort and dolphin/porpoise sighting data from the long-term monitoring database and the additional LNG survey data were stratified by season to calculate DPSE values (total number of dolphin/porpoises per unit of survey effort) within 1 km2 grids in the survey subareas. For humpback dolphins, line-transect data collected during 2003-06 were used, and DPSE values for grid squares in Deep Bay, Northwest Lantau, Northeast Lantau, West Lantau, Southwest Lantau and Southeast Lantau were examined (see Figure 9.40). For finless porpoise, line-transect data collected during 2002-06 were used (to allow larger sample size). Only Southwest and Southeast Lantau subareas were examined (see Figure 9.41) since finless porpoises do not occur in west and north Lantau waters.

Dolphins: Humpback dolphins showed different levels of seasonal differences in habitat use among the six survey areas (Figure 9.40). Seasonal habitat use patterns were less obvious in West Lantau and Northwest Lantau, and dolphins appeared to use two areas as their important habitats, with very high densities throughout the four seasons. Several areas were heavily used by dolphins in all four seasons, including the northern waters of Lung Kwu Chau (G9-10 & H9-10); northern waters of Tai O Peninsula (D23, E22-23 & F22); and waters between Kai Kung Shan and Fan Lau (D25-27, D29-30, C25-28).

On the other hand, Northeast Lantau and Southwest Lantau showed more distinct seasonal habitat use patterns. In Northeast Lantau, dolphin densities were moderately high in summer, autumn and winter months, but were generally low in spring months. Off Black Point (I7), dolphin density was highest in autumn. Similarly, the waters around the Brothers Islands were used consistently throughout the year, with higher dolphin densities in summer and autumn months.

In Southwest Lantau, dolphin usage was moderate to high across different seasons, except in spring. Dolphins used this area to a very low extent in spring months as compared to other seasons, with very limited occurrence near Fan Lau. Around the Soko Islands, dolphins seemed to disappear from this area in spring months, coinciding with the occurrence of finless porpoises (see below). Dolphins moderately used the waters around Sokos in the other three seasons. In 2003-06, no dolphin sighting was made in Southeast Lantau, and therefore seasonal patterns cannot be examined in this area.

In Deep Bay, dolphin usage was very low in spring and summer months, but was more intensified in autumn and winter months. In these two seasons, dolphins appeared to have preference to use the waters near the mouth of Deep Bay (H5, I5 & J55).

Porpoises: Seasonal habitat use patterns for finless porpoises were also examined in Southwest and Southeast Lantau using line-transect data collected in 2002-06. The porpoises showed distinct seasonal movement in southern waters of Lantau, with moderate to high usage in winter and spring months and extremely low usage in summer and autumn months (Figure 9.41).

In winter months, porpoises preferred to use the waters around the Soko Islands and south of Shui Hau Peninsula, while they did not use the waters along the coastline from Fan Lau to Shek Pik. In spring months, they appeared to move inshore to use the coastline from Fan Lau to Shek Pik more intensively, while they still moderately used the waters around North Soko. In summer and autumn months, porpoises generally shifted out of South Lantau waters, with only rare sightings made in the southern waters of South Soko.

Seasonal Habitat Partitioning: The waters around the Soko Islands and nearshore waters between Fan Lau and Shui Hau Peninsula are the areas in Hong Kong where both resident cetacean species occur in different seasons. The distinct seasonal shifts in porpoise usage in South Lantau corresponded well with humpback dolphin usage across different seasons. In spring months, porpoises shifted inshore to the coastal waters while dolphin usage was particularly low during this time of the year. In summer and autumn months, dolphins started to move back to South Lantau waters, while porpoises shifted out of these waters, resulting in higher densities of dolphins and rare usage by porpoises from June to November. Winter months appeared to be the transitional period when porpoises started to shift back to South Lantau waters while humpback dolphin usage was still moderately high.

Individual Movements and Patterns of Use

During the study period, a number of individual dolphins in all four of the study subareas were successfully identified (Figures 9.42 & 9.43). The individuals identified so far are listed in Table 9.23, along with an assessment of the importance of the subarea as part of the dolphin’s home range. The subarea was considered an important part of the dolphin’s range if >25% of the sightings of that individual occurred in the area.

Table 9.23 Individual Humpback Dolphins Observed during the LNG Study (July 2005 – May 2006)

Dolphin’s ID	Total sightings (1)	EIA Study sightings (2)	SWL (3) (4)	DB (3) (4)	West NWL (3) (4)	WL (3) (4)	HR Study?
CH03	18	1	1 (6%)		4 (22%)		Yes
CH06	25	2	3 (12%)			14 (56%)	Yes
CH37	7	1	1 (14%)		1 (14%)
DB02	2	2		2 (100%)
DB03	1	1		1 (100%)
EL01	43	1			6 (14%)	2 (5%)	Yes
EL03	5	1	1 (20%)		1 (20%)	1 (20%)
EL07	57	1			2 (4%)	2 (4%)	Yes
NL11	45	3		1 (2%)	16 (36%)		Yes
NL24	95	2			18 (19%)	7 (7%)	Yes
NL37	35	1			5 (14%)	2 (6%)	Yes
NL46	15	1			8 (53%)	2 (13%)	Yes
NL59	18	1			3 (17%)	3 (17%)	Yes
NL60	16	1			8 (50%)	2 (13%)	Yes
NL76	10	1			6 (60%)		Yes
NL98	47	1			6 (13%)	7 (15%)	Yes
NL123	43	5			11 (26%)	2 (5%)	Yes
NL128	10	1	2 (20%)		1 (10%)	6 (60%)	Yes
NL136	8	1			5 (63%)
NL139	42	1			5 (12%)	5 (12%)	Yes
NL141	31	1			6 (19%)	3 (10%)	Yes
NL150	7	1		1 (14%)	6 (86%)
NL169	10	3		3 (30%)	6 (60%)		Yes
NL170	4	1			2 (50%)	2 (50%)
NL181	14	5		4 (29%)	9 (64%)		Yes
NL191	9	1			2 (22%)	2 (22%)
NL202	6	1			4 (67%)	2 (33%)
SL07	13	2	2 (15%)			7 (54%)	Yes
SL35	5	3	3 (60%)			2 (40%)
SL36	1	1	1 (100%)
SL37	1	1	1 (100%)
WL11	16	2			6 (38%)	3 (19%)	Yes
WL25	22	2	1 (5%)		1 (5%)	15 (68%)	Yes
WL26	4	1	1 (25%)			3 (75%)
WL30	2	1		1 (50%)		1 (50%)
WL48	2	1				2 (100%)
WL51	4	2	2 (50%)			2 (50%)

Note: (1) Total sightings in the long-term database.

(2) Sightings in ERM’s surveys (July 2005 – May 2006) for this EIA Study.

(3) Number of sightings in each of the LNG survey areas (along with the proportion of the total in parentheses).

(4) Areas with >25% of the total sightings are in bold.

Twelve individuals of humpback dolphin were identified in the Southwest Lantau subarea during the study period. Of these, it appears that most of them use Southwest Lantau as only a portion of their home range, which generally extends further north and/or west. Although it would appear to be important for a few individuals it is noted that the sample size is too small to make a firm conclusion.

In the West Lantau subarea, 25 individuals were identified during this study, 11 of which used the subarea as a substantial part of their home range. There are many other individuals that used the West Lantau area over the last ten years of monitoring (at least 32 individuals), and 27 of these used the West Lantau area as part of their range in the period before the LNG study.

Northwest Lantau is used by a very large number of individuals (several dozen that use it at least on an occasional basis). Twenty-six dolphins were observed in North Lantau during the LNG surveys, and there appear to be at least 12 different individuals that used Northwest Lantau as part of their range during the study period. Only seven individuals were identified in Deep Bay during the LNG study. However, of these, five (DB02, DB03, WL26, NL169 and NL181) appeared to use Deep Bay as portion of their home range during the study period (although the sample sizes are small). In addition, two other individuals were identified in Deep Bay in previous surveys, and both of them used it as a significant part of their home range.

The ranging patterns of 21 individual dolphins identified during the 11 month surveys are shown in Figures 9.42 & 9.43. Among these individuals, 18 were identified in Northwest Lantau, 16 in West Lantau, 4 in Southwest Lantau, and 3 in Deep Bay. This indicates the importance of West Lantau and Northwest Lantau to humpback dolphins in Hong Kong. Of the four survey areas for this project, 68% of the individuals identified in the study period used at least one of the areas as a part of their home range.

Currently, among the 398 individuals identified in Hong Kong and Mainland waters of the Pearl River Estuary, 59 individuals (15%) were re-sighted 10 or more times, which were used in the ranging pattern analysis. Among them, 51 individuals (86%) had home ranges covering the western end of Northwest Lantau, while 36 individuals (61%) had ranges covering West Lantau. On the contrary, only 14 of the 56 individuals (24%) were sighted in Southwest Lantau, and only one (NL11) had range covering Deep Bay. The large proportion of identified individuals sighted in Northwest and West Lantau strongly suggested the importance of these habitats to the dolphins residing in the Pearl River Estuary.

Group Size and Composition

Humpback dolphin average group size was similar for the Northwest Lantau, West Lantau, and Southwest Lantau subareas (3.6-4.2 dolphins/group); however it was smaller for the Deep Bay subarea (3.0 dolphins) (Table 9.24).

Table 9.24 Average Group Size for Dolphins and Porpoises among the Different Survey Subareas

Species	Subarea	N	Mean	±SD	Range
Humpback dolphin	Deep Bay	55	3.0	2.4	1 to 12
	Northwest Lantau	62	3.7	2.9	1 to 17
	West Lantau	843	4.2	3.8	1 to 26
	Southwest Lantau	89	3.6	3.0	1 to 17
Finless porpoise	Deep Bay	0	-	-	-
	Northwest Lantau	0	-	-	-
	West Lantau	0	-	-	-
	Southwest Lantau	186	2.9	2.4	1 to 12

Finless porpoise average group size (all sightings from Southwest Lantau) was small, with an average of 2.9 porpoises per group (Table 9.24). It should be noted that for both species the standard deviation around the means was high indicating that group size varies markedly between sightings.

Due to the need to observe dolphin groups for extended periods at close range (which somewhat conflicted with the goal of completing all the transect lines), the surveys were only able to accurately record complete age class composition for a portion of the groups observed in each area (Table 9.25Table 9.25). In this subsample, all age groups were represented in each of the four survey subareas, except that no Unspotted Calves were found in Northwest Lantau (it is important to note this age class was observed in this area during the study; however, the subsample of data on groups with complete age class data did not include any groups with them). The absence of Unspotted Calves in Northwest Lantau appears to be a result of the small sample size. Previous surveys have observed many Unspotted Calves in the entire area north of Lantau Island. Besides that mentioned above, there were no dramatic differences in group composition among the different subareas, but there were some differences in the age classes most represented (i.e., those with greater than 20% of the total). Northwest Lantau has a smaller proportion of Mottleds (SJs) and higher proportion of Spotted Adults (SAs) than other areas, which would indicate somewhat older individuals in that area.

Table 9.25 Age Class Composition of Groups of Dolphins among the Four Survey Subareas (Percentage of Total Given in Parentheses). Data included this study and long-term data. Note that only groups in which the composition of the entire group was determined are presented

Area	No. of Groups	UC	UJ	SJ	SS	SA	UA
Deep Bay	19	8 (7%)	8 (14%)	13 (24%)	14 (25%)	13 (23%)	4 (7%)
Northwest Lantau	16	5 (11%)	5 (11%)	6 (13%)	12 (26%)	18 (39%)	5 (11%)
Southwest Lantau	24	4 (6%)	4 (6%)	21 (30%)	15 (21%)	19 (27%)	10 (13%)
West Lantau	231	78 (8%)	78 (8%)	206 (22%)	196 (21%)	210 (23%)	211 (24%)

Behaviour

Dolphin sightings associated with different types of activities were examined on GIS to determine important areas for certain types of dolphin activity. For sightings with dolphins engaged in feeding activities, most were made along the coastal waters of West Lantau, extending from Sham Wat to Peaked Hill (Figures 9.32-9.35).

In Northwest Lantau, most of the feeding activities occurred around Lung Kwu Chau and Sha Chau; while in Southwest Lantau, sightings associated with feeding activities were concentrated around the corner of Fan Lau. Feeding activities were rarely observed in Deep Bay.

Dolphins were occasionally observed socializing during the study period, and there was no particular area where sightings associated with socializing activities were frequently observed.

9.4 Evaluation of Ecological Importance of the Study Area

The existing conditions of the marine ecological habitats and resources in the waters of the proposed LNG terminal at South Soko Island and, those surrounding and those along the proposed submarine pipeline route have been assessed. These baseline conditions of individual marine habitat types have been based on available literature and, where considered necessary, detailed field surveys to update and supplement the data. Based on this information, the ecological importance of each habitat has been determined according to the EIAO-TM Annex 8 criteria, as follows:

· Naturalness

· Size

· Diversity

· Rarity

· Re-creatability

· Fragmentation

· Ecological Linkage

· Potential Value

· Nursery Ground

· Age

· Abundance

As noted previously, the marine waters and coastal habitats of the Southwest Lantau area including offshore islands of the Soko group, when taken as whole, are considered to be of high ecological importance and of conservation interest. Bearing this mind, it is also the case that within such a large area there are variations in the ecological characteristics of habitats in different areas. To provide information of key relevance to the marine ecological assessment, the ecological importance of habitats presented in this baseline is therefore primarily focused on the vicinity of the works areas of the proposed project.

9.4.1 Intertidal Habitats

The criteria listed below have been applied to the information gathered or reviewed on the marine ecology of the intertidal habitats at South Soko, Black Point and Shek Pik in order to determine the ecological value. The application of these criteria has led the artificial shoreline and the sandy shores to be classified as low and natural rocky shore as medium at South Soko (Table 9.26Table 9.26).

Table 9.26 Ecological Importance of Intertidal Habitats at South Soko

Criteria	Rocky Shore	Artificial Shorelines	Sandy Shore
Naturalness	The natural rocky shoreline is interspersed with areas of artificial seawall and are largely undisturbed by human activity	Artificial constructed habitat.	The shores are moderately disturbed
Size	Large in extent with the majority of South Soko shoreline consisting of this habitat	The length of the artificial shorelines at South Soko is relatively small at approximately 920 m	Small. The two sandy shores in the study area at South Soko total approximately 250 m in length
Diversity	Typical of exposed and semi-exposed rocky shores in Hong Kong.	Low. Artificial shores support similar assemblages to natural intertidal shores.	Very low. Only one species was recorded on the sandy shore and in low numbers
Rarity	No species recorded are considered rare or of recognised conservation interest.	No species recorded were rare or of recognised conservation interest	No species recorded are considered rare or of recognised conservation interest.
Re-creatability	The habitat is re-creatable.	N/A	The habitat is re-creatable.
Fragmentation	Low. Rocky shore is predominant intertidal habitat.	N/A	Moderate. Sandy shores form a small portion of the intertidal habitat in the Study Area and are also present on North Soko.
Ecological Linkage	The habitat is not functionally linked to any high value habitat in a significant way.	The habitat is not functionally linked to any high value habitat in a significant way	The habitat is not functionally linked to any high value habitat in a significant way
Potential Value	Low.	None identified	Low to moderate.
Nursery Area	No significant records identified during the literature review or field surveys.	No significant records identified during the literature review or surveys	Higher abundance of nearshore fish fry were reported at Pak Tso Wan. No significant records identified in the sandy shores during the literature review or surveys.
Age	n/a for these assemblages as the life cycle of the fauna and flora is short.	The artificial seawall has been in place since the detention centre was built in 1989	n/a for these assemblages as the life cycle of the fauna is short.
Abundance	Moderate. Typical species of similar composition and abundance as other exposed and semi-exposed rocky shores in Hong Kong.	Low. Assemblages similar to nearby rocky shores but in lower abundance.	Very low. This finding is typical of semi-exposed sandy beaches in Hong Kong.
SUMMARY	Rocky shore supports assemblages typical of exposed and semi-exposed shores in Hong Kong. . Ecological Importance - Medium.	Artificial shores support established assemblages similar to natural rocky shore but with lower abundance. Ecological Importance - Low.	Sandy shores are small and based on survey findings support low abundance and diversity of species. Ecological Importance – Medium for Pak Tso Wan Low for the remaining Sandy Shores.

Note: n/a: Not Applicable

The application of these criteria has led the artificial shoreline and natural rocky shore at Black Point to be classified as low ecological importance (Table 9.26).

Table 9.27 Ecological Importance of Intertidal Habitats at Black Point

Criteria	Rocky Shore	Artificial Shorelines
Naturalness	The natural rocky shoreline is interspersed with areas of artificial seawall and are largely undisturbed prior to the development of the thermal power station (BPPS) commenced in 1993.	Artificial, constructed habitat.
Size	Large. Within the Study Area, rocky shore habitat are approximately 390 m in total length and are predominant habitat on Black Point headland.	Large. The total length of the artificial shore in the Study Area at Black Point is approximately 522 m and are predominant habitat to the north of the power station.
Diversity	Low. The intertidal communities are composed of typical biota of semi-exposed rocky shores in Hong Kong, but with low diversity.	Records indicate that sloping artificial shores support similar assemblages to natural intertidal shores.
Rarity	No species recorded are considered rare or of recognised conservation interest.	No species recorded are considered rare or of recognised conservation interest..
Re-creatability	The habitat can be re-created.	n/a.
Fragmentation	Low. The surrounding environment contains similar intertidal habitats.	Low. The surrounding coastlines are composed of a mixture of natural and artificial intertidal shores.
Ecological Linkage	The habitat is not functionally linked to any high value habitat in a significant way.	The habitat is not functionally linked to any high value habitat in a significant way.
Potential Value	Unlikely that the site can develop conservation interest.	Unlikely to become an area of conservation value
Nursery Area	No significant records identified during the literature review or field surveys.	No significant records identified during the literature review or surveys
Age	n/a for these assemblages as the life cycle of the fauna and flora is very short.	The artificial seawall has been in place since the site access of Black Point Power Station was obtained in March 1993.
Abundance	Typical of other semi exposed shores in Hong Kong.	Lower abundance than natural rocky shore habitat.
SUMMARY	The fauna of the intertidal region appears to be typical of semi exposed shores in Hong Kong, but with low diversity. The sites appear to have suffered some human disturbance. Ecological Importance - Low.	The fauna of the intertidal region of the artificial shores is reported to support a similar diversity and abundance of intertidal organisms as natural shores. Ecological Importance - Low.

Note: n/a: Not Applicable

The application of these criteria has led the artificial shoreline, natural rocky shore and sandy shore at Shek Pik to be classified as low ecological importance (Table 9.28Table 9.28).

Table 9.28 Ecological Importance of Intertidal Habitats at Shek Pik

Criteria	Rocky Shore	Artificial Shorelines	Sandy Shore
Naturalness	Natural rocky shoreline occurs along the mouth of the bay away from developed areas and is largely undisturbed by human activity	Artificial constructed habitat.	Owing to their location close to Shek Pik maximum security prison the shores are largely undisturbed.
Size	Large in extent with the majority of the shoreline at the periphery of the study area consisting of this habitat	Medium in extent. The artificial shorelines at Shek Pik occurs in the middle part of the bay.	Large. The two sandy shores in the study area at South Soko total approximately 650 m in length
Diversity	The shore was characterised as a relatively low diversity of intertidal species shores compared to other semi-exposed rocky shores in Hong Kong.	Low. Artificial shores support similar assemblages to natural intertidal shores.	Very low. Only one species was recorded on the sandy shore and in low numbers
Rarity	No species recorded are considered rare or of recognised conservation interest.	No species recorded were rare or of recognised conservation interest	No species recorded are considered rare or of recognised conservation interest.
Re-creatability	The habitat is re-creatable.	N/A	The habitat is re-creatable.
Fragmentation	Low. Rocky shore is common intertidal habitat.	N/A	Low. Sandy shores form long contiguous stretches of the intertidal habitat in the Study Area and are also present at other locations along South Lantau.
Ecological Linkage	The habitat is not functionally linked to any high value habitat in a significant way.	The habitat is not functionally linked to any high value habitat in a significant way	The habitat is not functionally linked to any high value habitat in a significant way
Potential Value	Low.	None identified	Low.
Nursery Area	No significant records identified during the literature review or field surveys.	No significant records identified during the literature review or surveys.	No significant records identified during the literature review or surveys.
Age	n/a for these assemblages as the life cycle of the fauna and flora is short.	The artificial seawall was probably built as part of the prison development in the 1980s.	n/a for these assemblages as the life cycle of the fauna is short.
Abundance	Relatively low. Typical species of similar composition but generally lower abundance compared to other semi-exposed rocky shores in Hong Kong.	Low. Assemblages similar to nearby rocky shores.	Very low. This finding is typical of semi-exposed sandy beaches in Hong Kong.
SUMMARY	Rocky shore supports assemblages typical of semi-exposed shores in Hong Kong but with generally lower diversity and abundance. Ecological Importance -Low.	Artificial shores support established assemblages similar to natural rocky shore but with lower abundance. Ecological Importance - Low.	Sandy shores are large and based on survey findings support low abundance and diversity of species. Ecological Importance – Low.

Note: n/a: Not Applicable

9.4.2 Subtidal Habitats

The criteria listed above have been applied to the information gathered or reviewed on the marine ecology of the subtidal hard surface benthic habitat within the Study Area. The habitat has been classified as of low ecological value (Table 9.29Table 9.29).

Table 9.29 Ecological Importance of the Subtidal Hard Substrate Habitat at South Soko

Criteria	Subtidal Hard Surface Habitat along Natural Shoreline	Subtidal Hard Surface Habitat along Artificial Shoreline
Naturalness	Habitat is largely natural. There is evidence at the site of indirect impacts to the assemblages through poor water quality and deposited sediments.	The artificial habitat will have been largely undisturbed since the decommissioning of the detention centre. There is evidence at the site of indirect impacts to the assemblages through poor water quality and deposited sediments.
Size	Medium in extent. Predominant habitat fringing South Soko. Corals are restricted to shallows and have a very sparse and scattered occurrence.	The assemblages at South Soko extend along the entire length of the artificial shorelines of approximately 920 m, but are only found along a narrow band at depths of 3-4m below chart datum.
Diversity	A total of fifteen species of hard corals, including Porites lobata, Psammocora superficialis, Coscinarea sp., Pseudosiderastrea tayami, Turbinaria peltata, Balonophyllia sp.,Plesiastrea versipora, Leptastrea pruinosa, Cyphastrea sp, Echinophyllia sp, Favites abdita, Goniopora stutchburyi, Goniopora lobata, Oulastrea crispata and Tubastrea sp./ Dendronophyllia sp., and 4 genera of octocorals, including Dendronepthya, Euplexaura, Echinomuricea and Echinogorgia were recorded, with low diversity on west and east coast and moderate diversity on south coast of South Soko in comparison to other sites in Hong Kong.	One hard coral Oulastrea crispata and one octocoral Euplexaura were recorded, this is very low in comparison to other sites in Hong Kong.
Rarity	With the exception of the little known Pseudosiderastrea tayami recorded at two locations (Transects J & K) on the south coast of South Soko, all species of hard and soft corals are commonly recorded on rocky coasts across Hong Kong southern and eastern waters. P. tayami which was discovered in 2002 during a study to clarify taxonomic identities of Hong Kong hard corals, has only been recorded from 2 sites so far.	All species of hard and soft corals are commonly recorded on rocky coasts in Hong Kong.
Re-creatability	Hard bottom substrata may be recolonised by subtidal organisms including corals.	Hard bottom substrata may be recolonised by subtidal organisms including corals.
Fragmentation	Low. Similar subtidal habitats are situated around the shores of South Soko, Yuen Chau and Ma Chau.	Low. Similar subtidal hard surface habitats are situated around the shores of South Soko, North Soko, Yuen Chau and Ma Chau.
Ecological Linkage	The habitat is not functionally linked to any high value habitat in a significant way.	The habitat is not functionally linked to any high value habitat in a significant way.
Potential Value	Low. Conditions are marginal for coral growth this habitat supports sparse coral cover. High turbidity and high rates of sedimentation mean that the area is unlikely to become an area of coral conservation, although the location, where the little known, hardy coral Pseudosiderastra tayami is common, represents a notable record.	Very low. This habitat supported few coral species which were sparse in abundance. Conditions are not highly suited for coral growth. High turbidity and high rates of sedimentation mean that the area is unlikely to become an area of coral conservation.
Nursery Area	No significant records identified during the literature review or field surveys.	No significant records identified during the literature review or field surveys.
Age	Coral colonies were scattered and small. No large mature hard coral colonies were observed.	Coral colonies were scattered and small. No large mature coral colonies were observed.
Abundance	Very low live coral coverage was found in the study area.	Very low live coral coverage was found in the study area.
SUMMARY	Coral cover is very low in comparison to other sites in Hong Kong. Ecological Importance – Low except sites at Transect J & K on south coast of South Soko –Medium	Coral cover is very low in comparison to other sites in Hong Kong. Ecological Importance - Low.

Note: n/a: Not Applicable

The criteria listed above have been applied to the information gathered or reviewed on the marine ecology of the subtidal soft bottom benthic habitat at South Soko in order to determine the ecological value. The application of these criteria has led the habitat to be classified as of relatively low ecological value (Table 9.30Table 9.30).

Table 9.30 Ecological Importance of the Subtidal Soft Benthos Assemblages at South Soko and along the Corridor of the Proposed Submarine Natural Gas Pipeline

Criteria	Subtidal Soft Benthos at South Soko (SK 1 - SK 4, SSK 1 – SSK 4)	Subtidal Soft Benthos along the Corridor of the Proposed Submarine Natural Gas Pipeline (AC, PH, TO, MP1, MP2, UR & BP1)
Naturalness	Habitat disturbed to some extent by fisheries vessel trawling activities and is influenced by discharges from the Pearl River.	Habitat disturbed to some extent by fisheries vessel trawling activities and is influenced by discharges from the Pearl River.
Size	Habitat is large in extent.	Habitat is large in extent. Pipeline alignment is approx 40 Km
Diversity	The assemblages are of relative higher diversity (number of benthic species recorded per unit area above the mean value of the CityU (2002) data) compared to other areas in the Hong Kong waters.	The assemblages are of similar diversity to other areas in the Hong Kong waters.
Rarity	No infaunal organisms were found that are considered as rare. One epifaunal species listed as a Class II protected species in China – amphioxus Branchiostoma belcheri was recorded in grab samples taken from the eastern bay (SK3 in Tung Wan) of South Soko. This species has been recorded from a number of sites across eastern Hong Kong waters.	No organisms were found that are considered as rare or of recognised conservation interest.
Re-creatability	Benthic organisms may recolonise disturbed seabed areas.	Benthic organisms may recolonise disturbed seabed areas.
Fragmentation	The habitat is not fragmented.	The habitat is not fragmented.
Ecological Linkage	The habitat is not functionally linked to any high value habitat in a significant way.	The habitat is not functionally linked to any high value habitat in a significant way.
Potential Value	It is unlikely that the habitat could develop conservation interest.	It is unlikely that the habitat could develop conservation interest.
Nursery Area	No significant records identified in the review or surveys.	No significant records identified in the review or surveys.
Age	The fauna appear to be typical of those present in Hong Kong's soft benthos. The sediments in the habitat are constantly accreting and eroding and the fauna present there are typically short lived.	The fauna appear to be typical of those present in Hong Kong's soft benthos. The sediments in the habitat are constantly accreting and eroding and the fauna present there are typically short lived.
Abundance	In comparison to other parts of the southern and western waters the assemblages are of moderate abundance.	In comparison to other parts of the western waters the assemblages are of moderate abundance.
SUMMARY	The sediments support average diversity and abundance of benthic organisms that are typical of Hong Kong's benthos. Ecological Importance – Medium except SK3 in Tung Wan – High.	The sediments support average diversity and abundance of benthic organisms that are typical of Hong Kong's benthos. Ecological Importance – Low.

Note: n/a: Not Applicable

9.4.3 Marine Mammal Habitat off South Soko and along the Proposed Submarine Pipeline Route

The same assessment criteria have been applied to the marine waters within the Study Area with regard to the usage of the area by marine mammals. Both species are sighted in the waters of Southwest Lantau although typically at different times of the year. The submarine pipeline route has been divided in distinct areas in which dolphin use of the habitat differs markedly and has been based on the recent on effort sightings data from AFCD. The waters around West Lantau have been classified as of high ecological importance and the Northwest Lantau areas as medium ecological importance to Sousa chinensis. The section of the pipeline route from South Lantau to the Terminal at South Soko has been classified as of lower ecological importance to both Sousa chinensis and Neophocaena phocaenoides based on the comparatively lower number of sightings (Table 9.31Table 9.31).

Table 9.31 Ecological Importance of the Marine Waters off South Soko and along the Corridor of the Proposed Submarine Natural Gas Pipeline

Criteria	Marine Waters around South Soko	Along the Corridor of the Proposed Submarine Natural Gas Pipeline
Naturalness	Close proximity to the artificial shoreline and marine traffic lanes in Hong Kong.	Largely undisturbed in West Lantau and adjacent to the Sah Chau Lung Kwu Chau Marine Park. Other sections are in close proximity to marine traffic lanes in Hong Kong waters pass along the route.
Rarity	The South Lantau waters (extending from Fan Lau to south of Cheung Chau) is the only area in Hong Kong where there is a major spatial overlap in the distribution of Indo-Pacific Humpback dolphin and Finless Porpoises. There are however marked seasonal differences of these species use of South Lantau waters. Finless porpoises are generally absent from South Lantau waters in the seasons when dolphin abundance is at its highest. Therefore, while there is a strong spatial overlap, the temporal overlap is less pronounced due to strong seasonal habitat partitioning. Around South Soko, Indo-Pacific humpback dolphin Sousa chinensis has been recorded in coastal waters to the east (Tung Wan) and north (Lan Nai Wan) of South Soko, and the finless porpoise has been recorded in the west (Sai Wan) and north (the waters between North and South Soko) of South Soko.	Indo-Pacific humpback dolphin Sousa chinensis has been recorded along the majority of the waters of the route, whereas, sightings of the Neophocaena phocaenoides (are uncommon, if at all, along the entire route)
Re-creatability	n/a	n/a
Ecological Linkage	Preferred marine mammal habitat occurs to the north (north-western Lantau) for humpback dolphins and west (South Lamma) for finless porpoise of this area.	Route lies in waters that are utilised by humpback dolphins as part of their larger habitat. West Lantau and Northwest Lantau waters are major habitat for humpback dolphins.
Potential Value	South Soko Island has been considered as a potential marine park as was included in the Proposed Southwest Lantau Marine Park.	West Lantau and Northwest Lantau waters are highly utilised and are important parts of the home range for a number of animals. The W and SW Lantau areas, including Fan Lau, have been considered as a potential marine park and have been proposed for designation as such.
Nursery Area	Not key nursery areas in the review of baseline conditions or field surveys.	Review of baseline conditions and field surveys, indicated higher sightings of young animals off West Lantau in the waters surrounding or in proximity to the route. Monitoring data indicated that West Lantau has the highest sightings of dolphins and of mothers with calves compared to other areas of Hong Kong, which indicates the importance of this area to these animals.
Abundance	Seasonal changes in the distribution patterns of dolphins were observed near the areas of the proposed LNG terminal and pipeline route alignment, with comparatively higher sightings in spring and winter months. Abundance of dolphins is low at South Soko when compared to the preferred habitat in West and Northwest Lantau, however, Southwest Lantau is in the fourth most important dolphin habitat in Hong Kong among AFCD’s 12 survey areas. Finless Porpoise sightings are lower than areas such as Po Toi and vary strongly throughout the year; however, Southwest Lantau is the second most important porpoise habitat in Hong Kong among AFCD’s 12 survey areas.	Northwest and West Lantau are consistently highly utilised by dolphins with no strong seasonal variations. West Lantau represents highest use area by dolphins in Hong Kong. Limited sightings of the finless porpoise recorded along the route.
SUMMARY	Sightings of humpback dolphins and finless porpoise (occupying different areas) have been made in these waters. The number of sightings is low and seasonally varies. Ecological Importance: - Marine Waters at Tung Wan and Sai Wan of South Soko Low for Sousa chinensis, Medium for Neophocaena phocaenoides(2). - Marine Waters at the southeast of South Soko Island at the location of the LNG jetty Low for both Sousa chinensis and Neophocaena phocaenoides. - Marine Waters along the Corridor of the Proposed water main and submarine cable circuit Medium for both Sousa chinensis and Neophocaena phocaenoides.	Route passes through waters where sightings are common and consistent throughout the year. Sightings of finless porpoise are either low, or not all, along the route. Ecological Importance: Medium for both Sousa chinensis and Neophocaena phocaenoides west of South Soko(2). Medium in southwest Lantau for Sousa chinensis, Low for Neophocaena phocaenoides. High in west and northwest Lantau only for Sousa chinensis (1). Low at Black Point landing area only for Sousa chinensis.

Note: (1) The rank of ‘high’ is the highest rank that can be accorded to a habitat under ERM’s system for evaluating habitat importance. While both west and northwest Lantau are deemed to be of high ecological importance, it is recognised that West Lantau has greater dolphin sightings densities compared to northwest Lantau.

(2) It is noted that as a whole, the marine waters around South Soko may be considered as high ecological value in terms of general marine ecology.

9.4.4 Species of Recognised or Potential Conservation Interest Conservation Interest

In accordance with EIAO-TM Annex 8 criteria, species of recognised or potential conservation value and their conservation and protection status, are presented in Table 9.32.

Table 9.32 Species of Recognised or Potential Conservation Interest within the Study Area

Common Name	Scientific Name	Protection Status	Distribution, Rarity and other Notes
Chinese White Dolphin (also known as the Indo-Pacific Humpback dolphin)	Sousa chinensis	Wild Animals Protection Ordinance, Animals and Plant Ordinance, Class I Protected Species in the PRC, CITES Appendix 1, IUCN-listed (data deficient), Listed in UN Biodiversity Treaty	Range across Pearl River estuary and across Hong Kong western and Southern Waters from Deep Bay to Lamma.
Finless Porpoise (also known as the Black Finless Porpoise)	Neophocaena phocaenoides	Wild Animals Protection Ordinance, Animal and Plants Ordinance, Class I Protected Species in the PRC. CITES Appendix 1, IUCN-listed (data deficient)	Range from South Lantau to Mirs Bay (mainly in south and east of Hong Kong) and PRC waters
Amphioxus	Branchiostoma belcheri	Not protected in Hong Kong. Class II Protected Species in the PRC.	Recent studies indicate wider distribution than previously known. Recorded from across Hong Kong eastern waters from Sai Kung to Big Wave Bay.
False Pillow Coral	Pseudosiderastrea tayami	Wild Animals Protection Ordinance, Animal and Plants Ordinance	Little known species in Hong Kong recently discovered following study to clarify identity of Hong Kong hard corals. Species is difficult to identify in the field and so far is recorded from 2 locations in Hong Kong southern waters.

9.5 Summary

The findings from the literature review and field surveys on marine ecological conditions are detailed above and are summarized as follows.

The marine ecological habitats in the immediate vicinity of the South Soko Island have undergone some anthropogenic disturbance through reclamations in Sai Wan and Tung Wan as a result of the site formation for the Detention Centre (now decommissioned). Even before this facility was built there had been some modifications to the coastline, in the form of piers and seawalls, as a result of the village developments at Ha Tsuen and Sheung Tsuen (now abandoned). To the east of the South Soko Island lies the active mud disposal ground at South Cheung Chau and to the west a former marine sand borrow area.

The key finding of the literature review was the recorded presence in the waters in southern Lantau of both the Indo-Pacific humpback dolphin Sousa chinensis and the Finless Porpoise Neophocaena phocaenoides. Both species are sighted in the waters of Southwest Lantau although typically at different times of the year.

The review highlighted that the waters around the Soko Islands did not report large numbers of sightings. A higher number of sightings have been recorded in the waters along and in vicinity of the proposed submarine pipeline corridor in West Lantau, however, these were, and in general limited to be sightings of humpback dolphins only.

The ecological importance of the habitats was determined through reference to the following:

· Literature review;

· Findings of the field surveys;

· Comparison with other outlying islands in Hong Kong as well as South Lantau; and,

· Annexes 8 and 16 of the EIAO TM.

9.5.1 Dolphins and Porpoises

For this study, an extensive programme of vessel-based surveys have been conducted to supplement data available from ongoing long-term AFCD monitoring. These surveys have provided a detailed overview of dolphin utilisation of Hong Kong western waters spanning South West Lantau, West Lantau, North West Lantau and Deep Bay areas. During field surveys, dolphins were observed throughout all the surveyed areas except directly south of the Sha Chau/ Lung Kwu Chau Marine Park and the very northern end of the Deep Bay survey area.

Deep Bay has relatively low densities (0.08 - 0.23 dolphins km-2) and low estimates of abundance (<10 dolphins). As such it appears that dolphins use the mouth of Deep Bay at a low level throughout the year.

In contrast, West Lantau had highest dolphin densities (1.71 – 2.81 dolphins km-2) and comparatively higher abundance (47 - 78) of dolphins.

Southwest Lantau had lower levels of dolphin density (0.10 - 0.44 dolphins km-2) and abundance (26 - 29 dolphins) than West Lantau but higher than Deep Bay.

Northwest Lantau had lower levels of dolphin density (0.57-0.94) but similar abundance (49-82) compared to West Lantau. Northwest Lantau had higher levels of dolphin density and abundance than Deep Bay and Southwest Lantau.

Finless Porpoises were only seen in Southwest Lantau and estimates of abundance (0 - 15 porpoises) and density (<0.01 - 0.17 porpoises km-2) were low for all seasons. According to the literature ([108]), other areas of Hong Kong such as key habitats at Lamma and Po Toi were found to support considerably higher densities (Lamma: 0.02 - 0.52 porpoises km-2, Po Toi; 0.02 - 0.17 porpoises km-2) and abundance (Lamma: 4 - 90 porpoises, Po Toi: 4 - 32 porpoises) of these animals. However, based on the latest data, this situation may have changed as sightings were higher at the Po Toi area. In monitoring conducted in 2003 to 2005, finless porpoise sightings in South Lantau (12 sightings) were higher than in Lamma (2), Nine Pins (4) and Sai Kung (4), but lower than in Po Toi (15) ([109]).

9.5.2 Subtidal Hard Bottom Habitats

Dive surveys at South Soko for this EIA Study yielded similar results as BCL ([110]). In total, fifteen hard coral species and four octocoral species, were recorded within the Study Area (Annex 9). The majority were common faviids, poritids and siderasteriids with three predominant species – Oulastrea crispata, Psammocora sp. and the ahermatypic cup coral Balanophyllia sp.. Corals occurred in extremely low abundance and percentage cover estimates ranged from 1-5%. Many live corals recorded were highly bioeroded by macroborers and barnacles. The majority of colonies exhibited partial mortality and at most survey sites a low percentage cover of dead coral was noted. The corals recorded are all common Hong Kong species with the exception of the relatively little known hard coral, the False Pillow Coral Pseudosiderastrea tayami on the south coast of South Soko Island.

Subtidal Soft Bottom Habitats

A total of 96 grab samples were taken from 16 sites during both the wet and dry seasons: 8 of the sites (48 grabs) were located close to South Soko Island; 6 of the sites (36 grabs) were located along the submarine pipeline alignment; and 2 of the site (12 grabs) were located off Black Point. A total of 4,309 individual organisms were identified during the dry season surveys and 6,351 during the wet season survey. In both seasons, benthic assemblages were dominated by polychaete worms except off Black Point were bivalves had higher numbers. In terms of diversity and abundance, benthic communities at the sites were similar to other locations reported in Hong Kong. At sites close to South Soko Island, the level of diversity and biomass was generally higher than the Hong Kong average reported from the literature. In addition, a low number of amphioxus Branchiostoma belcheri were recorded in Tung Wan on the east coast of South Soko Island.

Intertidal Hard Bottom Habitats

Quantitative transect surveys and spotchecks were conducted on natural rocky shore and artificial seawalls on the west, east and south coasts of South Soko Island, Black Point and Shek Pik. Rocky shore species at all locations were common and widespread and no species of note were recorded. At South Soko, assemblages with the highest diversity were recorded on the south coast of the island. In comparison to records of other shores in Hong Kong reported in the literature, the diversity of intertidal biota at South Soko, was similar to other shores in Hong Kong.

Intertidal Soft Bottom Habitats

The sandy shores at South Soko and Shek Pik supported a very low species diversity in the dry and wet season, which is a typical feature of mobile sandy shores with unstable substrates.

Detailed and comprehensive seasonal surveys were conducted examining the major habitats and species surrounding the South Soko Island as well as along the provisional pipeline corridor to the Black Point Power Station. The details of the baseline surveys are summarized in Table 9.33Table 9.33.

Table 9.33 Marine Ecology Baseline Surveys

Survey Type	Methodology	Date
Intertidal Assemblages at South Soko	Rocky shore/ artificial shoreline Quantitative (belt transects at 9 locations) survey, three 100 m belt transects (at high, mid and low intertidal zones) for each location, covered both wet and dry seasons. Sandy Shore Quantitative (line transects at two locations) survey, 50 x 50 x 50cm core at three points (high, mid and low intertidal zones) along each of the transects, covered both wet and dry seasons.	8 & 9 March, 28 & 29 July and 14 September, 17 & 28 December 2004, 29 & 30 September 2005 and 27 January 2006
Intertidal Assemblages at Black Point	Rocky shore/ artificial shoreline Quantitative (belt transects at 6 locations) survey, three 100 m belt transects (at high, mid and low intertidal zones) for each location, covered both wet and dry seasons	22 & 23 March and 15 & 30 July 2004.
Intertidal Assemblages at Shek Pik	Rocky shore/ artificial shoreline Quantitative (belt transects at 1 locations) survey, three 100 m belt transects (at high, mid and low intertidal zones) covered both wet and dry seasons. Sandy Shore Quantitative (line transects at 3 locations) survey, 50 x 50 x 50cm core at three points (high, mid and low intertidal zones) along each of the transects, covered both wet and dry seasons.	30 August 2005 & 14 March 2006
Subtidal Benthic Assemblages	Quantitative grab sampling survey; covered both wet and dry seasons. Six stations sampled in each of 10 locations.	25 & 26 February, 5 & 6 July, 9 September and 8 November 2004, 23 September 2005 and 13 December 2005.
Subtidal Hard Bottom Habitat (Coral)	Quantitative (Rapid Ecological Assessment (REA) technique, a total of eight 100 m transects at 5 locations) and qualitative (recorded within Study Area and areas in the vicinity, 3 locations); covered wet season.	9 & 15 May 2004, 29,30 September & 3 October 2005.
Marine Mammal	Land-based visual survey during daytime, 5 days per month and 6 hours per day, covered four seasons (12 months).	13, 14, 21, 23 & 26 February, 8, 9, 10, 17 & 18 March, 16, 19, 20, 21 & 26 April, 10, 12, 14, 19 & 25 May, 10, 14, 17, 18 & 28 June 2004, 23, 26, 27, 28 & 29 July 2004, 25, 26, 27, 30 & 31 August, 6, 7, 13, 14 & 22 September 2004, 27, 28, 29, 30 & 31 October 2004, 16, 17, 24, 25 & 26 November 2004, 16, 21, 28, 30 & 31 December 2004, 10, 12, 14, 17 & 28 January 2005
	Quantitative vessel based survey using line transect methods spanning Hong Kong western waters (Deep Bay, Southwest Lantau,Northwest Lantau and West Lantau) 3 days, 2 times per month	18, 19, 20,21, 22, 25, 26, 27 July 2005, 3, 4, 5,15,24 & 25 August 2005, 5,7,15, 16 & 20 September 2005, 5, 6, 7, 17, 18 & 19 October 2005, 22, 24, 25, 28, 29 & 30 November 2005, 6,7,8 & 22 December 2005, 13, 16, 17, 19, 20 & 24 January 2006, 1, 2, 3, 7, 8 & 9 February 2006, 17, 23, 28, 29, 31 March 2006, 3, 6, 18, 25, 26, 27 April 2006, 2, 4, 8, 9, 10, 11 May 2006.

---

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([2]) The Hong Kong Institute of Education (1999) Study on the Suitability of South West Lantau to be Established as Marine Park or Marine Reserve. Report submitted to Marine Parks Division, AFCD.

([3]) AFCD (2004) Ecological Status and Revised Species Records of Hong Kong’s Scleractinian Corals, undertaken by Marine Conservation Division

([4]) BCL. 1997. Marine Ecology of Hong Kong: Report on Underwater Dive Surveys (October 1991 - November 1994).

([5]) ERM. 1998. Seabed Ecology Studies: Composite Report for CED.

([6]) ERM. 1998. ibid.

([7]) The Hong Kong Institute of Education (1999) Study on the Suitability of South West Lantau to be Established as Marine Park or Marine Reserve. Report submitted to Marine Parks Division, AFCD.

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([13]) City U Professional Services Limited. 2002. Final Report for Consultancy Study on Marine Benthic Communities in Hong Kong.

([14]) ERM. 1998. Seabed Ecology Studies: Composite Report for CED

([15]) ERM. 1998. ibid.

([16]) City U Professional Services Limited. 2002. Final Report for Consultancy Study on Marine Benthic Communities in Hong Kong.

([17]) City U Professional Services Limited. 2002. ibid.

([18]) Jefferson, pers comm.

([19]) Parsons C, Mary L. Felly and Lindsay J. Porter. 1995. An Annotated Checklist of Cetaceans recorded from Hong Kong’s Terrestrial Waters. The Swire Institute of Marine Science, The University of Hong Kong, Cape d’ Aguilar, Shek O, Hong Kong.

([20]) Jefferson T.A. 2000. Conservation Biology of the Finless Porpoise (Neophocaena phocaenoides) in Hong Kong waters: Final Report. Ocean Park Conservation Foundation Ocean Park Aberdeen, Hong Kong.

([21]) Jefferson T.A. 2000. Population Biology of the Indo-Pacific Humpback dolphin in Hong Kong waters. Wildlife Monographs 144:1-65.

([22]) Jefferson T.A., S.K. Hung, L. Law, M. Torey and N. Tregenza.2002. Distribution and Abundance of Finless Porpoise in Hong Kong and Adjacent Waters of China. The Raffles Bulletin of Zoology 2002 Supplement No. 10: 43-55.

([23]) Jefferson T.A. and S.K. Hung. 2004. A review of the status of the Indo-Pacific humpback dolphin in Chinese waters. Aquatic Mammals (Special Issue) 30: 149-158.

([24]) AFCD. 2004. Monitoring of Chinese White Dolphins (Sousa chinensis) in Hong Kong waters – Data collection, Final Report (1 April 2003 to 31 March 2004), prepared by Hong Kong Cetacean Research Project

([25]) AFCD. 2004. op. cit.

([26]) Jefferson T.A. 2000. Population Biology of the Indo-Pacific Humpback dolphin in Hong Kong waters. Wildlife Monographs 144:1-65.

([27]) Jefferson T.A. and S.K. Hung. 2004. A review of the status of the Indo-Pacific humpback dolphin in Chinese waters. Aquatic Mammals (Special Issue) 30: 149-158.

([28]) Barros, N.B., T.A. Jefferson, and E.C.M. Parsons. 2004. Feeding habits of Indo-Pacific humpback dolphins (Sousa chinensis) stranded in Hong Kong. Aquatic Mammals (Special Issue) 30: 179-188.

([29]) Jefferson, T. A. (ed.). 2005. Monitoring of Indo-Pacific humpback dolphins (Sousa chinensis) in Hong Kong waters – data analysis: final report. Unpublished report submitted to the Hong Kong Agriculture, Fisheries and Conservation Department.

([30]) Jefferson, T. A. (ed.). 2005. Ibid

([31]) Jefferson, pers. comm.

([32]) Jefferson, T. A. (ed.). 2005. Ibid.

([33]) Jefferson, pers comm.

([34]) Jefferson, pers. comm.

([35]) AFCD. 2005. Monitoring of Chinese White Dolphins (Sousa chinensis) in Hong Kong waters – Data collection, Final Report (1 April 2003 to 31 March 2004), prepared by Hong Kong Cetacean Research Project

([36]) Jefferson T.A. 2000. Conservation Biology of the Finless Porpoise (Neophocaena phocaenoides) in Hong Kong waters: Final Report. Ocean Park Conservation Foundation Ocean Park Aberdeen, Hong Kong.

([37]) AFCD 2005. Monitoring of Finless Porpoises (Neophocaena phocaenoides) in Hong Kong waters (2003-2005) Final Report, prepared by Hong Kong Cetacean Project.

([38]) AFCD. 2004. Monitoring of Chinese White Dolphins (Sousa chinensis) in Hong Kong waters – Data collection, Final Report (1 April 2003 to 31 March 2004), prepared by Hong Kong Cetacean Research Project.

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([48]) AFCD. 2004. Ecological Status and Revised Species Records of Hong Kong’s Scleractinian Corals, undertaken by Marine Conservation Division.

([49]) Veron J.E.N (2000) Corals of the World. Australian Institute of Marine Science.

([50]) AFCD. 2002. Agriculture, Fisheries and Conservation Department. Annual Report 2001-2002.

([51]) ERM. 1998. Seabed Ecology Studies: Composite Report for CED

([52]) ERM – Hong Kong Ltd. 2000. Environmental Impact Assessment, Construction of an International Theme Park in Penny’s Bay of North Lantau and its Essential Associated Infrastructures. Final EIA Report Annex (Volume 1)

([53]) AFCD. 2002. ibid.

([54]) Mouchel Asia Environmental. 1999. Feasibility Study for Additional Cross-border Links. Stage 2: Investigations on Environmental, Ecology, Land Use Planning, Land Acquisition, Economic/Financial Viability and Preliminary Project Feasibility/Preliminary Design – Final Ecological Impact Assessment Working Paper WP3 Appendices. Planning department, Government of the Hong Kong Special Administrative Region.

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([57]) ERM. 1998. Seabed Ecology Studies: Composite Report for CED.

([58]) ERM HK Ltd. 2002. Ecological Monitoring for Uncontaminated Mud Disposal. East Ninepins, South Tsing Yi, North Lantau and South Cheung Chau. Final Reports for Civil Engineering Department.

([59]) Rare Aquatic Organisms in China (1993)

([60]) City City U Professional Services Limited. 2002. Final Report for Consultancy Study on Marine Benthic Communities in Hong Kong.

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([62]) Morton B. & Morton J. (1983) The Seashore Ecology of Hong Kong. Hong Kong University Press.

([63]) ERM. 1998. Seabed Ecology Studies: Composite Report for CED.

([64]) City U Professional Services Limited. 2002. Final Report for Consultancy Study on Marine Benthic Communities in Hong Kong.

([65]) City U Professional Services Limited. 2002. Final Report for Consultancy Study on Marine Benthic Communities in Hong Kong.

([66]) ERM. 1998. Seabed Ecology Studies: Composite Report for CED

([67]) ERM. 2000. Environmental Impact Assessment, Construction of an International Theme Park in Penny’s Bay of North Lantau and its Essential Associated Infrastructures. Final EIA Report Annex (Volume 1)

([68]) City U Professional Services Limited. 2002. Final Report for Consultancy Study on Marine Benthic Communities in Hong Kong.

([69]) City U Professional Services Limited. 2002. ibid.

([70]) Jefferson T.A. 2000. Population Biology of the Indo-Pacific Humpback dolphin in Hong Kong waters. Wildlife Monographs 144:1-65.

([71]) Jefferson T.A. 2000. Conservation Biology of the Finless Porpoise (Neophocaena phocaenoides) in Hong Kong waters: Final Report. Ocean Park Conservation Foundation Ocean Park Aberdeen, Hong Kong.

([72]) Jefferson T.A., S.K. Hung, L. Law, M. Torey and N. Tregenza. 2002. Distribution and Abundance of Finless Porpoise in Hong Kong and Adjacent Waters of China. The Raffles Bulletin of Zoology 2002 Supplement No. 10: 43-55.

([73]) Jefferson T.A., S.K. Hung, L. Law, M. Torey and N. Tregenza. 2002. ibid.

([74]) Jefferson T.A., S.K. Hung, L. Law, M. Torey and N. Tregenza. 2002. ibid.

([75]) Parsons E.C.M. 1998. The Behaviour of Hong Kong’s Resident Cetaceans: the Indo-Pacific Hump-Backed Dolphin and the Finless Porpoise. Aquatic Mammals 1998, 24.3, 91-110.

([76]) Jefferson, pers comm.

([77]) Beasley I. and Jefferson T.A. 2000. Surface and Dive Times of Finless Porpoise in Hong Kong’s Coastal Waters. The Raffles Bulletin of Zoology 2002 Supplement No. 10: 125-129.

([78]) Jefferson T. A. 2000. Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters. Wildlife Monographs 144: 66.

([79]) Jefferson, T. A. (ed.). 2005. Monitoring of Indo-Pacific humpback dolphins (Sousa chinensis) in Hong Kong waters – data analysis: final report. Unpublished report submitted to the Hong Kong Agriculture, Fisheries and Conservation Department.

([80]) Jefferson T. A. 2000. Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters. Wildlife Monographs 144: 66.

([81]) Jefferson T. A. , S. K. Hung, L. Law, M. Torey and N. Tregenza. 2002. Distribution and Abundance of Finless Porpoise in Hong Kong and Adjacent Waters of China. The Raffles Bulletin of Zoology 2002 Supplement No. 10: 43-55.

([82]) Parsons E. C. M., M. L. Felley and L. J. Porter. 1995. An annotated checklist of cetaceans recorded from Hong Kong’s territorial waters. Asian Marine Biology 12:79-100.

([83]) Jefferson T. A. , S. K. Hung, L. Law, M. Torey and N. Tregenza. 2002. ibid.

([84]) Jefferson T. A. and S. Leatherwood. 1997. Distribution and abundance of Indo-Pacific hump-backed dolphins (Sousa chinensis Osbeck, 1765) in Hong Kong waters. Asian Marine Biology 4:93-110.

([85]) Jefferson T. A. 2000. Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters. Wildlife Monographs 144: 66

([86]) Jefferson T. A. , S. K. Hung, L. Law, M. Torey and N. Tregenza. 2002. ibid..

([87]) Würsig B. and T. A. Jefferson 1990. Methods of photo-identification for small cetaceans. Reports of the International Whaling Commission (Special Issue) 12:43-52.

([88]) Jefferson T. A. and S. Leatherwood. 1997. Distribution and abundance of Indo-Pacific hump-backed dolphins (Sousa chinensis Osbeck, 1765) in Hong Kong waters. Asian Marine Biology 4:93-110.

([89]) Jefferson T. A. 2000. Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters. Wildlife Monographs 144: 66

([90]) Jefferson T. A. , S. K. Hung, L. Law, M. Torey and N. Tregenza. 2002. Distribution and Abundance of Finless Porpoise in Hong Kong and Adjacent Waters of China. The Raffles Bulletin of Zoology 2002 Supplement No. 10: 43-55.

([91]) Buckland S. T., D. R. Anderson, K. P. Burnham and J. L. Laake. 2001. Distance Sampling: Estimating Abundance of Biological Populations. Chapman and Hall, Landon, UK.

([92]) Laake J. L., S. T. Buckland, D. R. Anderson and K. P. Burnham. 1994. DISTANCE User’s Guide, Version 2.1. Colorado Cooperative Fish and Wildlife Research Unit, Fort Collins, CO, USA.

([93]) Buckland S. T., D. R. Anderson, K. P. Burnham and J. L. Laake. 2001. Distance Sampling: Estimating Abundance of Biological Populations. Chapman and Hall, Landon, UK.

([94]) Jefferson T. A. 2000. Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters. Wildlife Monographs 144: 66

([95]) Jefferson T. A. , S. K. Hung, L. Law, M. Torey and N. Tregenza. 2002. Distribution and Abundance of Finless Porpoise in Hong Kong and Adjacent Waters of China. The Raffles Bulletin of Zoology 2002 Supplement No. 10: 43-55.

([96]) Buckland S. T., D. R. Anderson, K. P. Burnham and J. L. Laake. 2001. Distance Sampling: Estimating Abundance of Biological Populations. Chapman and Hall, Landon, UK.

([97]) Jefferson T. A. 2000. Population biology of the Indo-Pacific hump-backed dolphin in Hong Kong waters. Wildlife Monographs 144: 66

([98]) Jefferson T. A. , S. K. Hung, L. Law, M. Torey and N. Tregenza. 2002. Distribution and Abundance of Finless Porpoise in Hong Kong and Adjacent Waters of China. The Raffles Bulletin of Zoology 2002 Supplement No. 10: 43-55.

([99]) Jefferson T. A. 2000. ibid.

([100]) Jefferson T. A. 2000. ibid.

([101]) Jefferson T. A. , S. K. Hung, L. Law, M. Torey and N. Tregenza. 2002. ibid.

([102]) Hung S. K. and T. A. Jefferson. 2004. Ranging patterns of Indo-Pacific humpback dolphins (Sousa chinensis) in the Pearl River Estuary, People’s Republic of China. Aquatic Mammals (Special Issue) 30: 159-174

([103]) There are certain limitations associated with the land-based survey. It should be noted that there is a decrease in detection objects with increase in distance from the observer. It should also be noted that part of the jetty location, turning circle and approach channel were obscured from view by the island’s terrain.

([104]) Jefferson, T. A. (ed.). 2005. Monitoring of Indo-Pacific humpback dolphins (Sousa chinensis) in Hong Kong waters – data analysis: final report. Unpublished report submitted to the Hong Kong Agriculture, Fisheries and Conservation Department.

([105]) Jefferson TA, Hung S, Law L, Torey M, Tregenza N. 2002. Distribution and abundance of finless porpoises in Hong Kong and adjacent waters of China. The Raffles Bulletin of Zoology Supplement 10:43-55.

([106]) AFCD 2005. Monitoring of Finless Porpoises (Neophocaena phocaenoides) in Hong Kong waters (2003-2005) Final Report, prepared by Hong Kong Cetacean Project.

([107]) Not available at time of writing

([108]) Jefferson TA, Hung S, Law L, Torey M, Tregenza N. 2002. Distribution and abundance of finless porpoises in Hong Kong and adjacent waters of China. The Raffles Bulletin of Zoology Supplement 10:43-55.

([109]) AFCD 2005. Monitoring of Finless Porpoises (Neophocaena phocaenoides) in Hong Kong waters (2003-2005) Final Report, prepared by Hong Kong Cetacean Project.

([110]) Binnie Consultants Limited. 1997. Coastal Ecology Studies – Soko Islands (Qualitative Survey). Final Report to GEO, Civil Engineering Department.