9.         InTroduction.. 9-1

9.1       Background. 9-1

9.2       Relevant Legislation. 9-1

9.3       Baseline Conditions. 9-3

9.4       Key Issues. 9-14

9.5       Impact Evaluation. 9-17

9.6       Mitigation Measures. 9-27

9.7       Cumulative Impacts. 9-28

9.8       Residual Impacts. 9-32

9.9       Environmental Monitoring and Audit 9-33

9.10     References. 9-33

9.                              InTroduction

9.1                          Background

9.1.1.1              This section of the EIA presents details of the assessment of the potential impacts to fisheries resources within the study area and describes the sensitive receivers present, potential impacts from the project and recommends suitable mitigation measures.  In order to achieve the aforementioned measures, the major objectives of the assessment are as follows:

·                     description of the physical environmental background;

·                     description and quantification as far as possible of the existing fisheries activities;

·                     identification of parameters and area that are important to fisheries;

·                     identification and quantification as far as possible of any direct or indirect and on-site or off-site impacts to fisheries; and

·                     proposals for any practicable alternatives or mitigation measures to prevent or minimise adverse impacts on fisheries and recommendations for any monitoring and audit.

9.1.1.2              The fisheries impact assessment will be undertaken in accordance with Annexes 9 and 17 of the EIAO Technical Memorandum.

9.2                          Relevant Legislation

9.2.1.1              The assessment area for fisheries impact assessment is largely focused in the North Western Water Control Zone (WCZ) in which the project is located.  The adjacent water control zones such as the Deep Bay WCZ and the Western Buffer WCZ are distant from the project alignment and the Water Quality Assessment will be able to confirm if the project and related activities would cause any significant impacts to these two WCZs.  Special attention has been given to the fishing activities within the project area and the Ma Wan fish culture zone (FCZ) within the Western Buffer WCZ which is the nearest gazetted mariculture area.

9.2.1.2              Relevant legislation applicable to this Study includes:

·                     the Marine Fish Culture Ordinance (Cap. 353) which regulates and protects marine fish culture zones (FCZ) that are designated under the ordinance. It is a criminal offence to discharge polluting substances into an FCZ;

·                     the Fisheries Protection Ordinance (Cap. 171) which regulates fishing activities for the conservation of fisheries resources and other marine life;

·                     the Water Pollution Control Ordinance (Cap. 358) which specifies a set of Water Quality Objective (WQO) for each water control zone. Specific WQOs are also stipulated for fish culture subzone and of particular relevance to this Study are:

-        annual geometric mean of bacteria Escherichia coli not to exceed 610 cfu/100ml; and

-       The depth-averaged dissolved oxygen should not be less than 5 mg/l for 90% of the samples. In addition, bottom dissolved oxygen should not be less than 2 mg/l for 90% of the samples.

·                     reference was also made to Annexes 9 and 17 of the Technical Memorandum EIAO (Cap. 499) in order to determine the potential impacts to fisheries resources in the Study Area. The criteria include the following:

-        to prevent any significant impacts to sensitive fisheries areas particularly the nursery and spawning grounds of commercially important species of fish, crustaceans, molluscs and other marine life;

-        to prevent significant loss or interference with the use of fishing grounds and FCZ’s; and

-        to prevent significant impacts to local fishery resources and fishing activities.

9.2.1.3              A review of relevant EIAs and reports has also been conducted in order to assist the assessment criteria. These reports include the following:

·                     New Airport Master Plan (Greiner-Maunsell, 1991);

·                     Feasibility Study & Environmental Impact Assessment for Aviation Fuel Pipeline (Montgomery Watson, 1996);

·                     Feasibility Study for Additional Cross-border Links Stage 2 (Mouchel, 1998);

·                     EIA for the Proposed Sand Extraction from The Brothers’ Marine Borrow Area (Hyder Consulting, 1998);

·                     EIA Study for Disposal of Contaminated Mud in the East Sha Chau Marine Borrow Pit (ERM, 1997, 2005);

·                     EA Study for Backfilling of Marine Borrow Pits at North of the Brothers (Mouchel, 2002);

·                     Route 10 North Lantau to Yuen Long Highway Investigation and Preliminary Design EIA (Mott Connell, 1999);

·                     Hong Kong- Zhuhai- Macao Bridge: Hong Kong Section and the North Lantau Highway Connection: Ecological Baseline Survey (Mouchel, 2004); and

·                     Port Survey 2006, Fisheries Management Division, AFCD (AFCD, 2009b).

9.2.1.4              Reports from the on-going environmental monitoring and audit at the contaminated mud pits at East of Sha Chau (Mouchel, 2001, 2005b; Meinhardt, 2006b), also, provide a large amount of relevant fisheries data and have been reviewed.  The fisheries data provided in the aforementioned EM&A study provide the most up to date information on the fisheries resources of the Study Area.

9.3                          Baseline Conditions

9.3.1                    Description of Physical Habitat

9.3.1.1              A detailed description of the physical marine habitat will be presented in the Water Quality Assessment and the key aspects are summarised below.  The Tuen Mun – Chek Lap Kok Link (TM-CLKL) is located in the north-western water control Zone (WCZ) of Hong Kong which are strongly influenced by freshwater discharges from the Pearl River, especially during the wet season when the summer monsoon brings high levels of precipitation.  The seabed in the area is generally characterised by soft material composed of silts and clay as a homogenous layer or in loosely packed mud clasts bound in a puzzle fabric (Binnie Consultants, 1995; ERM, 1999; Mouchel, 2001), although coarser material under the influence of strong tidal currents has been reported from the area to the northeast of the Brothers (Greiner-Maunsell, 1991). There are, also, some hard substrates present although the soft-bottom sediments are characteristic of the Study Area.  The benthic habitat has relatively low to moderate diversity of burrowing in-fauna present compared to other locations in Hong Kong (Mouchel, 2001; Meinhardt, 2006c).  The benthos is highly sediment laden and the resident fauna are dominated by representatives that tolerate high ambient suspended solid loads (Mouchel, 2002).

9.3.1.2              In terms of water quality, there are significant pollution inputs from the Pearl River catchment resulting in significant nutrient loading and generally eutrophic conditions (Mouchel, 2002, 2004a, b; Huang et al, 2003).  The predominantly estuarine fish inhabiting the north-western waters are, therefore, naturally subjected to certain environmental stresses notably high suspended solids concentrations. Although many estuarine fish are tolerant of elevated suspended solids concentrations (e.g., CPCC, 2001), they may suffer sub-lethal stress (often associated with damage to the gills) when held in such conditions over prolonged periods (O’Connor et al, 1977).

9.3.1.3              The broad study area contains areas of fishing importance as detailed below and shown in Figure 9.1:

·                     Fishing grounds covering much of the open waters of the North-western waters;

·                     Spawning and nursery grounds for fish and shrimp;

·                     Ma Wan Fish Culture Zone (FCZ); and

·                     Artificial Reefs at Sha Chau and Lung Kwu Chau Marine Park and Chek Lap Kok Marine Exclusion Zone 3, at the north-east corner of the airport island.

9.3.1.4              Further details of these resources are discussed below.

9.3.2                    Capture Fisheries

9.3.2.1              The local fishing industry makes an important contribution to Hong Kong fresh marine fish supply.  In 2008, an estimated 158,000 tonnes of fisheries products valued at $1,780 million were landed.  It should noted that the annual fisheries production of about 158,000 tonnes represents the landing statistics by Hong Kong fishing vessels operating both within and outside Hong Kong and could either over-estimate or under-estimate the productivity of local fishing grounds.  However, it remains the best available indicator and is used to provide a reference for the magnitude of any impacts only.  The industry consists of about 3,800 fishing vessels and just under 8,000 fishermen working aboard and also provides employment in ancillary sectors servicing the fishing industry, such as fish wholesale and retail marketing, fuel and fishing gear supply and ice manufacturing (AFCD, 2009a).  The estimated production in 2008 was similar (slightly higher) to the 2007 level of 154,000 tonnes and the 2006 level of 155,000 tonnes (AFCD, 2007, 2008). Hong Kong has just over 165,000ha of open waters which is mostly available for fishing (EPD, 2006).

9.3.2.2              The Agriculture, Fisheries and Conservation Department (AFCD) carry out port surveys periodically to collect information on the fisheries production and operation in Hong Kong waters.  The surveys consist of an interview programme.  In 2006, AFCD carried out the latest round of port survey to collect updated data for the year 2005.  The survey interviewed 36% of the local fishing fleets which accounted for all homeports (38 ports) and vessel types (10 types).  The survey results have been presented in density maps. The overall adult fish production was categorised into 6 classes: >0-50, 50-100, 100-200, 200-400, 400-600 and 600-1000 kg/ha (/grid). The fishing operation was also categorized into 6 classes: >0-10, 10-50, 50-100, 100-400, 400-700 and 700-1000 vessels (/grid).

9.3.2.3              Based on the Port Survey 2006 (AFCD, 2009b), the waters around Chek Chau (Tolo Channel), Ninepins and Po Toi Island were the most productive areas with production in the highest 600-1000 kg/ha class.  The overall adult fish production around the Brothers Islands in the North-western Water Control Zone (NWWCZ), was comparatively low with four grid areas at 200-400 kg/ha and the others at 0-50 and 50-100 kg/ha (Figure 9.2a).  Within the North-western WCZ, the waters off Tai O are the most productive with a class range of 400-600 kg/ha. The results of the Port Survey 2006 indicated, however, that fry collection has become very limited throughout Hong Kong waters.  Fish fry production was concentrated in the eastern waters (Mirs Bay, Tolo Harbour and Channel, Port Shelter and Po Toi), although a minor production was also reported in the East Lamma Channel. There was no fish fry production recorded in the study area (Figure 9.2b).

9.3.2.4              In terms of fishing operations, essentially the vessels operate over the whole Hong Kong waters at a fairly even density. However, slightly more fishing vessels work in the waters around Chek Chau, Ninepins, Po Toi and South Lamma, similar to overall adult fish production. Fishing operations at north Lantau used to be fairly intense. In 2005, the number of vessels (not exceeding 15m in length) operating near the Brothers was generally at the middle classes of 100-400 vessels/grid and 50-100 vessel/grid (Figure 9.3a) while the number of vessels (exceeding 15m in length) was at the lower classes of 50-100 vessels/grid and 10-50 vessel/grid (Figure 9.3b). Small crafts, especially sampans, dominated the operating vessels near the Brothers.

9.3.2.5              The distribution of the fisheries production in term of value in Hong Kong during 2006 is presented in Figure 9.4.  The value of fisheries production within the study area was in the range of HK$1,000-5,000/ha, overall, which is of moderate value in comparison to other areas in Hong Kong waters. There is a small area within the Sha Chau and Lung Kwu Chau Marine Park that has a value of HK$5,000-10,000/ha, although fishing in marine parks are generally restricted and only fishermen and villagers with a valid permit are allowed to fish in this area. This marine park, however, will not be affected by the project as discussed below.

9.3.3                    Fisheries Resources

9.3.3.1              In terms of fisheries resources, the Port Survey 2006 revealed that the top five categories of fish species captured in Hong Kong waters were: (1) mixed fish; (2) family carangidae (Scad, Yellowstripe scad, Purple amberjack); (3) mixed shrimp (Shrimp, Rice prawn, Middle shrimp, Shiba shrimp, Spear shrimp, Japanese king prawn, Banana prawn, Bear prawn, Rough shrimp, Silver shrimp and coastal mud shrimp); (4) family siganidae (Rabbitfish); and (5) mixed squid (Port Survey 2006). The main species caught near the Brothers area was Carangidae, Shrimp and croaker with the highest production of 20-40 kg/ha (AFCD, 2009b).

9.3.3.2              The northern Lantau waters are not identified as a primary nursery ground, however, they were previously identified in 1998 as important fisheries spawning grounds for high value commercial species (Figure 9.1) (ERM, 1998).  This spawning area is approximately 10km long (from Tai Mo To island to Lung Kwu Chau Island) and 5km wide (from Castle Peak to the northernmost tip of the Airport). The main commercial fish species reported included Leiognathus brevirostris (ponyfish), Lateolabrax japonicus (sea bass/ perch) and Clupanodon punctatus (gizzard shad).

9.3.3.3              Quantitative fisheries trawling is conducted as part of the on-going EM&A programme for the contaminated mud pits at sites around Lung Kwu Chau, off the airport and around the mud pits.  The fisheries trawling data available covered both the dry (January-February 2005; Mouchel, 2005b) and wet (October 2005; Meinhardt, 2006b) seasons from the North-western waters.  The trawling locations are presented in Figure 9.1.

9.3.3.4              The January-February 2005 dry season survey recorded a total of 177 different species. Of these faunal groups, crabs, fish, gastropods, shrimps (including mantis shrimp) and prawns were the most abundant. The gastropods were numerically dominant and 3,163 individuals were trawled during January-February 2005. Fish were the second most abundant and 2,638 individuals were recorded in the dry season.  They were the most diverse group represented by 66 different species. In terms of numerical dominance, the most common fish recorded were the croaker (Johnius macrorhynus), the gobies (Trypauchen vagina), Saddleback silver-biddy (Gerres lucidus (=limbatus)) and mullet (Valamugil formosae).  The commercially important mantis shrimps (mostly Oratosquilla interrupta) and prawns (Metapenaeus spp. and Penaeus spp.) were also numerically abundant components of the trawls.  Crabs were also abundant and 2,085 individuals were recorded in the dry season.  The commercially important group (cephalopods, crabs, gastropods, fish, mantis shrimps and prawn shrimps) trawled from locations around Sha Chau during the January-February 2005 dry season are presented below in Table 9.1 although it should be noted that not all the species are commercial species.

9.3.3.5              The closest trawling stations to the proposed TM-CLKL alignment are FS6 and FS5, approximately 0.6km and 2.3km away, respectively (Figure 9.1).  As indicated in Table 9.1 below, in dry season crab and fish at FS5 and FS6 are more abundant and diverse than other stations.  At FS5 and FS6, 1,281 crab individuals were recorded which is over 60% of the total crab catch, and were represented by 23 species out of 30 total crab species recorded. There were 1,329 fish individuals recorded at FS5 and FS6, which is about 50% of the total fish catch, and were represented by 55 species out of 66 total fish species recorded. While the gastropods were dominant group in the area, it is not abundant at FS5 and FS6.

Table 9.1         Species Composition and Abundance of Individuals (Total Counts) from Trawling in Dry Season (January-February 2005)

Group

Species

Trawling Station

Total

FS1

FS2

FS3

FS4

FS5

FS6

Cephalopod

Loligo sp.

 

2

7

3

4

5

21

 

Octopus sp.

 

 

3

 

1

2

6

 

Sepiella japonica

 

 

 

 

 

1

1

 

Sepiella sp.

 

 

1

2

 

1

4

Cephalopod Total

 

0

2

11

5

5

9

32

Crab

Charybdis acuta

13

 

3

 

11

12

39

 

Charybdis affinis

1

4

3

 

19

12

39

 

Charybdis anisodon

 

 

 

 

1

 

1

 

Charybdis cruciata

5

2

7

1

16

14

45

 

Charybdis hellerii

 

3

 

 

4

 

7

 

Charybdis japonica

111

151

85

50

510

222

1,129

 

Charybdis truncata

 

7

7

1

9

21

45

 

Charybdis variegata

5

9

 

3

2

12

31

 

Clibanarius sp.

1

8

24

27

34

39

133

 

Diogenes sp.

 

11

 

3

41

 

55

 

Doclea ovis

 

2

 

 

 

 

2

 

Dorippe polita

 

1

 

 

 

 

1

 

Eriochier sp.

1

 

 

 

 

 

1

 

Ethusa indica

4

1

14

19

6

10

54

 

Eucrate costata

14

28

3

2

30

5

82

 

Eucrate crenata

3

6

 

2

7

1

19

 

Galene bispinosa

7

 

4

3

1

 

15

 

Goniohellenus vadorum

 

11

40

35

 

3

89

 

Leucosia vittata

 

6

 

 

3

21

30

 

Macrophthalmus japonicus

 

 

 

1

 

1

2

 

Macrophthalmus latreillei

 

1

 

 

 

 

1

 

Platylambrus validus

 

4

9

9

4

50

76

 

Portunus hastatoides

 

2

5

3

9

4

23

 

Portunus pelagicus

 

 

 

 

9

14

23

 

Procelain crab

 

2

1

2

28

91

124

 

Scalopidia spinosipes

 

 

 

 

 

1

1

 

Thalamita sima

 

 

2

 

2

2

6

 

Typhlocarcinops denticarpes

 

 

1

 

 

 

1

 

Typhlocarcinus nudus

5

4

 

 

 

 

9

 

Typhlocarcinus villosus

1

 

 

1

 

 

2

Crab Total

 

171

263

208

162

746

535

2,085

Fish

Acentrogobius caninus

5

3

14

11

83

25

141

 

Ambassis gymnocephalus

23

 

 

 

 

 

23

 

Amblychaeturichthys hexanema

6

10

1

2

3

 

22

 

Apogon kiensis

 

 

 

 

2

 

2

 

Apogon lineatus

 

 

 

 

 

1

1

 

Apogon pseudotaeniatus

 

1

 

 

 

 

1

 

Arnoglossus tenuis

 

 

1

1

9

5

16

 

Chaeturichthys stigmatias

15

25

4

5

1

 

50

 

Chrysochir aureus

 

 

1

 

 

 

1

 

Coilia grayii

9

27

2

 

 

1

39

 

Collichthys lucidus

2

8

2

 

6

1

19

 

Cryptocentrus filifer

 

 

 

 

20

1

21

 

Cynoglossus arel

20

15

6

5

47

26

119

 

Cynoglossus gracilis

 

 

 

 

 

1

1

 

Cynoglossus itinus

 

 

 

 

 

1

1

 

Cynoglossus joyneri

21

18

13

7

10

1

70

 

Cynoglossus puncticeps

 

2

 

 

2

2

6

 

Cynoglossus semilaevis

10

6

1

 

8

6

31

 

Dasyatis bennettii

 

 

 

 

 

4

4

 

Dasyatis zugei

 

 

1

 

 

 

1

 

Dendrophysa russelii

17

26

15

29

12

19

118

 

Epinephelus bruneus

 

 

 

 

1

 

1

 

Gerres lucidus

 

 

7

10

20

145

182

 

Gymnothorax reevesii

 

 

 

 

1

 

1

 

Ilisha elongata

2

5

 

 

 

 

7

 

Inegocia japonica

 

 

 

 

4

3

7

 

Inimicus japonicus

 

 

 

 

1

2

3

 

Johnius belangerii

1

11

1

 

2

15

30

 

Johnius macrorhynus

12

15

134

59

86

222

528

 

Larimichthys polyactis

 

 

2

 

 

 

2

 

Lateolabrax japonicus

 

1

 

 

 

1

2

 

Leiognathus brevirostris

1

1

1

1

8

38

50

 

Liza affinis

 

 

 

1

 

 

1

 

Muraenesox cinereus

 

1

 

1

1

 

3

 

Nemipterus japonicus

 

 

1

1

1

 

3

 

Ophichthus celebicus

 

 

 

 

1

 

1

 

Otolithes ruber

 

 

4

3

1

2

10

 

Oxyurichthys tentacularis

4

 

8

13

7

3

35

 

Parachaeturichthys polynema

8

50

4

3

13

2

80

 

Pennahia argentata

 

 

1

2

3

2

8

 

Pisodonophis cancrivorus

 

 

 

 

1

 

1

 

Platycephalus indicus

4

4

16

14

23

24

85

 

Plotosus lineatus

 

 

1

 

 

1

2

 

Polydactylus sextarius

 

1

5

15

5

5

31

 

Prionobutis koilomatodon

 

 

 

 

 

1

1

 

Pseudorhombus arsius

 

 

1

 

 

1

2

 

Saurida elongata

 

 

 

2

 

 

2

 

Scatophagus argus

 

 

 

 

 

4

4

 

Sebastiscus albofasciatus

 

 

 

 

 

1

1

 

Sebastiscus marmoratus

 

 

 

 

 

1

1

 

Siganus canaliculatus

 

1

2

 

 

5

8

 

Sillago sihama

1

 

 

1

9

27

38

 

Solea ovata

 

3

3

2

43

68

119

 

Syngnathus schlegeli

3

3

5

6

3

 

20

 

Takifugu niphobles

 

 

 

1

 

 

1

 

Takifugu oblongus

 

 

 

 

 

3

3

 

Takifugu poecilonotus

 

 

 

 

 

1

1

 

Takifugu xanthopterus

 

 

 

 

 

1

1

 

Thryssa chefuensis

 

 

 

 

 

1

1

 

Thryssa hamiltonii

 

4

3

 

10

2

19

 

Trachycephalus uranoscopa

1

1

3

2

18

43

68

 

Trichiurus lepturus

1

 

 

 

 

1

2

 

Trypauchen vagina

155

122

10

20

66

54

427

 

Uroconger lepturus

 

 

1

2

 

 

3

 

Valamugil formosae

 

 

50

77

5

20

152

 

Zebrias zebra

3

1

 

 

 

 

4

Fish Total

 

324

365

324

296

536

793

2,638

Gastropod

Brachytoma sp.

2

26

14

11

7

 

60

 

Bufonaria rana

13

29

20

27

11

4

104

 

Bullacta exarata

 

 

1

2

 

 

3

 

Cancellaria sp.

 

 

1

 

 

 

1

 

Capulus sp.

 

1

 

 

 

 

1

 

Cheilea sp.

 

1

 

 

13

 

14

 

Crassispira pseudoprinciplis

 

1

 

 

 

 

1

 

Gyrineum natator

 

 

 

1

 

 

1

 

Hemifusus tuba

 

 

1

 

 

1

2

 

Hindsia suturalis

 

1

 

 

 

 

1

 

Lophiotoma leucotropis

6

5

6

14

4

 

35

 

Murex trapa

52

54

68

66

31

26

297

 

Nassarius crematus

9

40

113

196

 

 

358

 

Nassarius sp.

 

 

6

 

 

 

6

 

Nassarius succinctus

 

2

 

 

 

 

2

 

Natica sp. 1

3

 

3

10

 

 

16

 

Phalium bisulcatum

 

 

1

3

 

1

5

 

Polynices sp.

 

1

 

 

 

1

2

 

Rapana bezoar

 

 

 

 

 

12

12

 

Rapana sp.

1

 

 

1

 

 

2

 

Sea slug

 

1

 

 

 

 

1

 

Siphopatella sp.

 

1

 

1

3

5

10

 

Thais mutabilis

 

 

1

 

 

 

1

 

Thais sp.

 

1

 

1

2

 

4

 

Tonna sp.

 

 

2

1

 

 

3

 

Turricula javana

4

8

9

4

1

2

28

 

Turricula nelliae

 

1

 

 

 

 

1

 

Turricula sp.

 

 

1

 

 

 

1

 

Turritella terebra

123

113

903

985

51

16

2191

Gastropod Total

 

213

286

1150

1323

123

68

3163

Mantis shrimp

Clorida decorator

1

 

 

1

 

1

3

 

Dictyosquilla foveolata

6

2

 

1

 

 

9

 

Harpiosquilla harpax

5

3

24

17

7

8

64

 

Oratosquilla interrupta

90

46

31

41

29

11

248

 

Oratosquilla oratoria

6

7

15

11

43

24

106

Mantis shrimp Total

 

108

58

70

71

79

44

430

Prawn or Shrimp

Alpheus brevicristatus

1

5

 

3

17

1

27

 

Alpheus distinguendus

26

43

5

11

7

 

92

 

Alpheus hoplocheles

 

5

 

1

 

 

6

 

Exopalaemon carinicauda

25

 

 

 

 

 

25

 

Metapenaeopsis barbata

 

1

1

 

9

 

11

 

Metapenaeus affinis

48

6

 

2

2

36

94

 

Metapenaeus burkenroadi

1

2

4

3

 

1

11

 

Metapenaeus ensis

9

1

 

3

27

5

45

 

Metapenaeus joyneri

18

20

7

33

7

7

92

 

Parapenaeopsis hardwickii

177

36

1

6

18

2

240

 

Parapenaeopsis hungerfordi

287

250

12

16

32

7

604

 

Penaeus orientalis

3

3

7

8

29

143

193

 

Penaeus penicillatus

 

 

 

3

3

 

6

 

Scyllarus martensii

 

 

 

1

 

3

4

 

Solenocera crassicornis

157

70

3

20

2

1

253

 

Trachypenaeus curvirostris

1

2

 

1

1

 

5

 

Trachypenaeus fulvus

12

10

1

 

 

2

25

Prawn or Shrimp Total

 

765

454

41

111

154

208

1,733

Note: Not all crab species are commercially important although they are important components of the marine system and are included for completeness.  Source: Mouchel (2005b).

9.3.3.6              The October 2005 late wet season survey (Table 9.2) recorded a total of 165 different species.  Of these faunal groups, bivalves, crabs, fish, gastropods, shrimps (including mantis shrimp) and prawns were also the most abundant.  The gastropods were numerically dominant and 26,056 individuals were trawled in October 2005.  Crabs and fish were also abundant and 4,644 individuals of crabs and 3,671 individuals of fish were recorded in the wet season. While bivalve were the second most dominant group, it was mainly due to the blooming of Potamocorbula sp. clam at FS2 and only a few were recorded at the other stations. It should also note that not all these crabs, fish and gastropods are commercial species and when compared to the results of the dry season surveys, blooming of molluscs (bivalve and gastropods) were often recorded in the area (Mouchel, 2005a).

9.3.3.7              Similar to the dry season results, fish recorded in the wet season were the most diverse group and were represented by 69 different species.  In terms of numerical dominance, the most common fish recorded were the mullet (Mugil cephalus), the gobies (Trypauchen vagina), the pony fish (Leiognathus brevirostris), another gobies (Oxyurichthys tentacularis) and the Striped threadfin (Polydactylus sextarius). The commercially important mantis shrimps (mostly Oratosquilla interrupta) and prawns (Metapenaeus spp. and Penaeus spp.) were also numerically abundant components of the trawls.

9.3.3.8              As indicated in Table 9.2 below, crab and fish at FS5 and FS6 were also more abundant and diverse than other stations in the wet season.  At FS5 and FS6, 1,542 crab individuals were recorded, which is about 33% of the total crab catch, and were represented by 28 species out of 32 total crab species recorded. There were 1,317 fish individuals recorded at FS5 and FS6, which is about 35% of the total fish catch, and were represented by 52 species out of 69 total fish species recorded.

9.3.3.9              In general, the trawling results for the NWWCZ were broadly similar to major categories of fish species captured in Hong Kong waters.     

Table 9.2   Species Composition and Abundance of Individuals (Total Counts) from Trawling in Wet Season (October 2005)

Group

Species

Trawling Station

Total

FS1

FS2

FS3

FS4

FS5

FS6

Cephalopod

Loligo sp.

 

 

 

1

 

2

3

 

Octopus sp.

 

 

 

1

7

2

10

 

Sepiella sp.

2

 

 

 

 

 

2

Cephalopod Total

 

2

0

0

2

7

4

15

Crab

Calappa philargius

 

8

 

 

 

60

68

 

Calappa sp.

 

 

 

 

 

2

2

 

Charybdis acuta

19

116

9

8

112

35

299

 

Charybdis affinis

80

273

59

74

165

81

732

 

Charybdis callianassa

 

 

 

 

 

15

15

 

Charybdis cruciata

1

18

52

20

53

26

170

 

Charybdis hellerii

 

 

 

 

2

9

11

 

Charybdis japonica

96

804

469

279

413

215

2,276

 

Charybdis truncata

 

 

9

 

1

2

12

 

Charybdis variegata

 

2

 

 

2

2

6

 

Clibanarius sp.

27

148

31

23

16

45

290

 

Diogenes sp.

5

20

 

2

13

2

42

 

Doclea gracilipes

2

20

1

7

 

1

31

 

Doclea ovis

 

6

 

 

 

 

6

 

Dorippe polita

 

1

 

 

 

 

1

 

Ethusa indica

2

 

81

85

13

47

228

 

Eucrate costata

 

 

 

 

16

 

16

 

Eucrate crenata

 

24

3

 

3

 

30

 

Galene bispinosa

2

23

5

 

2

4

36

 

Goniohellenus vadorum

7

1

24

40

30

16

118

 

Halimede sp.

 

 

 

 

 

1

1

 

Leucosia vittata

 

2

15

5

 

6

28

 

Macrophthalmus japonicus

 

 

2

 

 

 

2

 

Platylambrus validus

 

 

2

3

4

8

17

 

Porcelain crab

 

 

3

 

17

17

37

 

Portunus hastatoides

2

6

4

28

1

8

49

 

Portunus pelagicus

1

4

 

3

37

19

64

 

Portunus sanguinolentus

8

2

2

8

11

6

37

 

Portunus trituberculatus

1

 

 

1

 

 

2

 

Scylla serrata

 

 

 

 

 

1

1

 

Thalamita sima

 

 

 

 

 

1

1

 

Typhlocarcinus nudus

4

 

5

7

1

1

18

Crab Total

 

257

1478

774

593

912

630

4,644

Fish

Acentrogobius caninus

11

7

20

26

49

11

124

 

Ambassis gymnocephalus

 

 

2

 

 

 

2

 

Amblychaeturichthys hexanema

7

 

 

1

 

 

8

 

Apogon kiensis

5

24

5

7

40

18

99

 

Apogon lineatus

 

1

 

 

 

1

2

 

Arnoglossus tenuis

1

 

 

1

2

5

9

 

Brachyamblyopus brachysoma

 

 

 

1

 

 

1

 

Callionymus japonicus

 

 

2

 

 

 

2

 

Cephalopholis boenak

 

 

1

 

 

 

1

 

Chelonodon patoca

 

 

 

 

2

 

2

 

Chrysochir aureus

 

 

 

 

4

 

4

 

Coilia nasus

3

11

 

 

 

 

14

 

Collichthys lucidus

4

31

1

 

2

2

40

 

Cryptocentrus filifer

 

 

1

 

1

 

2

 

Cynoglossus arel

6

12

12

21

19

14

84

 

Cynoglossus joyneri

18

6

9

12

1

 

46

 

Cynoglossus puncticeps

 

 

1

 

1

1

3

 

Cynoglossus semilaevis

1

 

1

1

 

 

3

 

Dasyatis akajei

 

 

 

 

 

2

2

 

Dasyatis bennettii

 

 

1

 

 

 

1

 

Dasyatis zugei

 

 

 

 

 

1

1

 

Dendrophysa russelii

4

5

15

7

 

6

37

 

Drepane punctata

 

 

 

 

 

2

2

 

Epinephelus awoara

 

 

 

 

1

2

3

 

Epinephelus bruneus

 

 

 

 

2

4

6

 

Gerres lucidus

 

 

5

1

33

20

59

 

Harpadon microchir

 

5

 

 

 

 

5

 

Ilisha elongata

1

2

1

2

 

 

6

 

Inegocia japonica

2

1

 

 

12

18

33

 

Inimicus japonicus

 

 

 

 

1

1

2

 

Johnius belangerii

8

6

 

1

66

93

174

 

Johnius macrorhynus

8

17

11

17

103

28

184

 

Lagocephalus gloveri

 

 

 

 

1

 

1

 

Leiognathus brevirostris

11

1

47

154

55

16

284

 

Leiognathus nuchalis

23

 

 

 

 

 

23

 

Liza macrolepis

 

 

 

12

 

 

12

 

Minous monodactylus

 

 

 

 

 

2

2

 

Mugil cephalus

3

 

57

514

8

 

582

 

Muraenesox bagio

 

 

 

 

 

1

1

 

Muraenesox cinereus

1

2

3

 

4

1

11

 

Nemipterus japonicus

 

 

1

2

9

9

21

 

Nibea albiflora

 

 

 

 

8

 

8

 

Otolithes ruber

 

 

 

1

 

 

1

 

Oxyurichthys tentacularis

8

23

82

97

3

9

222

 

Parachaeturichthys polynema

4

53

 

 

1

1

59

 

Pennahia argentata

11

29

2

2

1

4

49

 

Pisodonophis boro

 

 

 

 

1

1

2

 

Platycephalus indicus

9

5

44

30

53

49

190

 

Polydactylus sextarius

88

12

26

15

47

27

215

 

Pseudorhombus arsius

 

 

 

 

 

1

1

 

Repomucenus richardsonii

1

 

 

1

1

5

8

 

Rhynchopelates oxyrhynchus

 

 

 

 

 

1

1

 

Saurida elongata

1

 

7

11

1

3

23

 

Sebastiscus marmoratus

 

 

 

 

3

3

6

 

Siganus canaliculatus

1

 

7

9

44

99

160

 

Sillago sihama

 

 

 

 

3

11

14

 

Solea ovata

2

10

1

4

41

8

66

 

Syngnathus schlegeli

 

 

3

4

 

 

7

 

Takifugu ocellatus

5

 

6

 

1

10

22

 

Takifugu poecilonotus

 

 

 

 

 

2

2

 

Terapon jarbua

 

 

1

3

6

35

45

 

Terapon theraps

 

 

 

 

21

 

21

 

Thryssa hamiltonii

 

1

3

 

1

2

7

 

Thryssa sp.

 

 

 

 

 

2

2

 

Trachycephalus uranoscopa

33

1

2

1

23

27

87

 

Trypauchen vagina

255

65

30

28

56

27

461

 

Upeneus japonicus

 

 

 

1

 

 

1

 

Valamugil formosae

3

 

83

4

 

 

90

 

Zebrias zebra

 

1

 

1

 

1

3

Fish Total

 

538

331

493

992

731

586

3,671

Gastropod

Brachytoma sp.

2

10

 

3

 

 

15

 

Bufonaria rana

10

5

142

87

7

5

256

 

Calyptraea sp.

 

 

 

 

1

 

1

 

Cancellaria sp.

 

1

 

10

 

 

11

 

Hemifusus tuba

 

 

1

 

 

 

1

 

Lophiotoma leucotropis

7

9

2

 

 

 

18

 

Murex trapa

53

126

599

325

52

38

1193

 

Nassarius crematus

1

30

66

214

2

 

313

 

Nassarius sp.

 

2

20

 

 

 

22

 

Nassarius succinctus

 

 

3

 

 

 

3

 

Natica sp.

4

2

 

 

 

 

6

 

Natica sp. 1

21

 

2

 

 

 

23

 

Nudibranch

1

5

 

5

 

 

11

 

Rapana bezoar

 

5

 

4

 

12

21

 

Siphopatella sp.

 

 

 

24

 

 

24

 

Turricula javana

3

3

1

2

1

 

10

 

Turritella terebra

327

55

12257

11004

293

192

24128

Gastropod Total 

 

429

253

13093

11678

356

247

26056

Mantis shrimp

Clorida sp.

 

 

 

 

1

 

1

 

Dictyosquilla foveolata

 

 

5

 

 

 

5

 

Harpiosquilla harpax

9

41

312

308

82

34

786

 

Miyakea nepa

1

 

3

1

 

 

5

 

Oratosquilla interrupta

271

263

34

28

42

13

651

 

Oratosquilla oratoria

15

28

35

22

13

2

115

Mantis shrimp Total

 

296

332

389

359

138

49

1,563

Prawn or shrimp

Alpheus brevicristatus

4

1

1

 

5

1

12

 

Alpheus distinguendus

5

3

 

 

 

 

8

 

Alpheus hoplocheles

 

3

 

 

 

 

3

 

Exopalaemon annandalei

 

1

 

 

 

 

1

 

Metapenaeopsis barbata

1

1

 

 

3

 

5

 

Metapenaeus affinis

630

120

114

199

28

22

1,113

 

Metapenaeus ensis

7

1

 

 

7

5

20

 

Metapenaeus joyneri

1

9

2

6

 

3

21

 

Parapenaeopsis hardwickii

45

18

40

21

43

21

188

 

Parapenaeopsis hungerfordi

63

31

33

23

35

19

204

 

Penaeus monodon

 

1

 

 

 

1

2

 

Penaeus orientalis

 

1

17

12

16

22

68

 

Penaeus penicillatus

1

 

1

2

 

4

8

 

Solenocera crassicornis

113

86

64

81

3

5

352

Prawn or shrimp Total

 

870

276

272

344

140

103

2,005

Note: Not all crab species are commercially important although they are important components of the marine system and are included for completeness.  Source: Meinhardt (2006b).

9.3.4                    Culture Fisheries

9.3.4.1              There are no fish culture zones (FCZ) located within close proximity to the TM-CLKL alignment.  The closest gazetted culture fishery is the Ma Wan FCZ located more than 10km away from the alignment.  This is the only FCZ in the area which may potentially be affected by construction of the TM-CLKL.  The Ma Wan FCZ consists of 107 licensed floating rafts as of February 2009 and traditionally the main species cultured are spotted grouper (Epinephelus chlorostigma), goldlined seabream (Rhabdosargus sarba), mangrove snapper (Lutjanus argentimaculatus) and pompano (Trachinotus blochii) (Mott Connell, 1999; Mouchel, 2002).  There are, also, no oyster farming locations near the proposed alignment. The closest oyster production areas are located in the Deep Bay mudflats between Tsim Bei Tsui and Ha Pak Nai, about 15 km away. 

9.3.5                    Artificial Reefs

9.3.5.1              Artificial reefs (ARs) have been deployed in Sha Chau and Lung Kwu Chau Marine Park and at the Chek Lap Kok Marine Exclusion Zone (Figure 9.1) to enhance the habitat quality and marine resources of the area and as a feeding station for Chinese White Dolphin.  A total of 76 ARs, with a total volume of 9,180 m3, have been deployed since 2000.  The ARs in Hong Kong have been reported to support higher biodiversity and abundance of commercial fishes than nearby natural rocky shore habitat and more than 220 fish species, including many commercially important as well as some rare species, have been recorded between 1998 and 2003.  The nearest AR at the Chek Lap Kok Marine Exclusion Zone is located approximately 1km away from the proposed TM-CLKL alignment (Figure 9.1) and is more likely to be affected by the project than the AR at Sha Chau and Lung Kwu Chau Marine Park.  However, the proposed HKBCF and associated facilities are only 300m away from the AR at the Chek Lap Kok Marine Exclusion Zone.

9.3.6                    Fisheries Surveys

9.3.6.1              The currently available data summarised above provides a comprehensive and up to date account of the status of the fisheries resources in the study area.  The data are considered adequate on which to base the assessment of potential impacts resulting from the TM-CLKL project and, therefore, no data gap in the fisheries baseline data has been identified and, as such, no fisheries field surveys are considered to be required.

9.4                          Key Issues

9.4.1.1              The key potential issues associated with the project alignment with respect to fisheries are related to the permanent loss of fishing grounds due to reclamation and piers of the marine viaduct foundations during the construction and operational phase, the temporary loss of seabed habitat due to any other marine works and also seabed disturbance and release of suspended solids in to the water as a result of dredging and filling activities during the construction phase.  Details of the construction of the project are provided in Section 3 of this report.  Notwithstanding the above, as described in Section 2, in order to avoid and minimise the amount of dredging required by the project, the TM-CLKL tunnel is proposed to be constructed by Tunnel Boring Machines (TBM) and, as such, temporary disturbance to the seabed and generation of suspended solids along the tunnel alignment would not occur during the construction phase.  A detailed account of the potential impacts attributed to alterations of the seabed and suspension of sediments to marine ecological receivers will be presented in Sections 6 and 8 of this report (Water Quality and Marine Ecology) and, as such, potential impacts applicable to fisheries resources only are summarised below.

Loss of Seabed Habitat

9.4.1.2              As described in Section 3, the project requires reclamation at Pillar Point, Tuen Mun (northern landfall reclamation) and at the north-east of the airport island (southern landfall reclamation) for the landing of the tunnel link.  The piers for marine viaduct section between the southern reclamation and landfall at north Lantau would, also, occupy some seabed areas for the pile foundations, although the area required is relatively small compared to the reclamation. These would result in permanent loss of seabed.

9.4.1.3              While the tunnel section between the two reclamations is to be constructed using TBM, as the tunnel gradient increases to the portals, there is potential for habitat loss of seabed area.  However, as described in Section 3 and shown in Figures 3.3a, 3.3c, 3.6a and 3.6b, these areas are fully contained within the reclamation areas at either end of the tunnel and, therefore, additional seabed loss will not occur.

Suspension of Sediments

9.4.1.4              Notwithstanding the potentially negative impacts of seabed loss described above, however, there are also potential positive effects of dredging to fisheries resources within the immediate vicinity of the works.  In the short-term, the disturbance to the seabed during dredging is likely to provide opportunities for feeding by fish as resident invertebrate prey populations are displaced from the sediments.  Dredging has, for example, been known to attract dolphins (Hyder, 1998; Meinhardt, 2006d.), who are presumably attracted to the vicinity of dredged areas to feed on fish similarly attracted by dislodged invertebrates.

9.4.1.5              During construction phase, dredging and backfilling at the reclamation, and for the viaduct piers, will have the potential to cause temporary elevated levels of suspended solids (SS) in the ambient water column, which may cause indirect impacts to nearby fisheries sensitive receivers, for example, the spawning grounds in north Lantau and the artificial reef deployed at Chek Lap Kok Airport Exclusion Zone. The potential direct and indirect impacts from suspended solids to fisheries resources are summarised in Table 9.3 below.

Table 9.3     Potential Direct and Indirect Impacts from Suspended Solids to Fisheries Resources

Potential Impacts from Suspended Solids

Direct Impacts

1.      physical abrasion and clogging of gills

2.      interference with feeding apparatus

3.      alteration of behaviour, especially in species that rely heavily on visual cues

4.      higher susceptibility to diseases

5.      smothering of early-life stages particularly eggs

 

Indirect Impacts

1.      suspended matter may reduce light penetration and alter primary productivity

2.      large volumes of deposited suspended solids may alter the nature of the seabed

3.      suspended matter may contain organics that have an oxygen demand leading to reduced dissolved oxygen

4.      contaminants may be released, especially during dredging, if the sediments are contaminated

 

9.4.1.6              High suspended solid concentrations can have a lethal effect on adult fish through suffocation as gills clog and dysfunction. At lower concentrations, sub-lethal effects may be manifested as disruption to feeding, mating behaviour (loss of visual cues) and may also increase the susceptibility of the fish population to a range of chronic diseases including fungal, parasitic, bacterial and viral infections. The impacts from suspended solids are most notable to the younger stages such as larvae and eggs. The eggs of fisheries species are particularly vulnerable to sediment deposition as smothering prevents/impedes gaseous exchange inducing mortality to the developing embryo.  Most adult fish are, however, adapted to the naturally-occurring sediment fluxes of the North-western waters and will respond to localised elevated concentrations of suspended solids by avoiding the area. Avoidance behaviour will not, however, be possible under mariculture conditions.

9.4.1.7              The indirect impacts on fisheries from elevated suspended solid concentrations in the marine environment are difficult to quantify owing to numerous other confounding factors present.  There is, however, some evidence that elevated suspended solid concentrations would reduce photosynthesis rate and interfere with primary productivity that may initially have implications for herbivorous fish, alter the seabed leading to losses of prey items and, when suspended matter has a high organic content, there is potential for an increased oxygen demand leading to localised hypoxia.

Suspension of Contaminated Sediments

9.4.1.8              Resuspension of highly contaminated sediments may lead to the desorption of contaminants into the water column that may eventually be taken-up into food chains that are linked to fisheries resources.  Based upon a review of historical data collected for other projects, EPD routine sediment monitoring data and samples taken and analysed for this project specifically, as detailed in full in Section 6 of this report, the sediments in the study area have been concluded, however, to be relatively uncontaminated overall and the release of contaminants during dredging should be minimal.  This is further discussed below.  The material used for the reclamation filling will also be clean material (most likely imported sand and/or inert public fill) and free from contamination. Sediment re-suspension is, therefore, not considered likely to cause significant elevation of potentially polluting naturally-bound constituents such as metals in ambient waters through desorption and potential toxic impact from resuspension of contaminated sediments to fisheries resources is not expected.

9.5                          Impact Evaluation

9.5.1                    Construction Phase

9.5.1.1              Annex 9 of the Technical Memorandum EIAO provides general criteria that can be applied in the assessment of impacts to fisheries due to developments. As described above, construction phase impacts to fisheries associated with the TM-CLKL are mostly related to the potential for impacts from permanent and temporary loss of fishing grounds, adverse effects of water quality and temporary loss of seabed and disturbance.  The construction phasing and programming of the project are detailed in Section 3 and Section 6, but the marine works are currently planned to commence in October 2011 and is anticipated to last for about 42 months.   

9.5.1.2              In assessing the potential impacts, relevant criteria and guidelines have been followed.  In particular the WQOs stipulate specific criteria for dissolved oxygen (DO) and bacteria E. coli levels for FCZs.  For suspended solids (SS), the WQO  used for the protection of general aquatic communities is 30% above ambient, although an AFCD sponsored toxicological/ tolerance study has demonstrated that local fish held in elevated SS levels as high as 5,000 mg/L do not elicit notable impacts (CityU, 2001) and based on this study a protective criterion of 50 mg/L for fishes was subsequently proposed.  This guideline has been used in several EIA studies for FCZs and is proposed for this study.  Water quality modelling has also been conducted for this project and detailed in Section 6 which also provides valuable information about potential project related changes in water quality which is useful for assessing the impact potential impacts to fisheries resources and culture facilities.

9.5.1.3              The following sections provide an evaluation of the direct and indirect potential impacts to fisheries resources from the construction of the TM-CLKL project.

Loss of Fishing Grounds

9.5.1.4              Construction works (including reclamation land formation and construction of bridge piers) occupying the sub-tidal marine areas will lead to the direct loss of some fishing grounds.  For the reclamation of tunnel portal areas and the formation of bridge piers, the seabed will be reclaimed permanently. This will cause a direct decrease of fisheries resources as these areas will no longer be available for fisheries production and operation.  Restriction of fishing operations around the working vessels (for safety) may also be required causing some fishing areas to be temporarily not available.  The extent of these impacts would depend on the size of reclamation, the preferred construction method and also the fisheries productivity of the area being affected.  For the temporary loss, it also depends on the duration of the works. 

9.5.1.5              It should be noted that the reclamation required under the preferred TM-CLKL alignment has already been reduced in area where possible and as such minimised the potential impacts to the fisheries resources and fishing grounds as far as practicable.  The major actions are described in Section 2 and include:

·                     Relocating the toll plaza from reclamation to a land based near the Tuen Mun Area 46 and, thus, minimising the northern landfall reclamation size;

·                     Combining the southern landfall area with HKBCF and, thus, avoiding the core fishing ground near around the Brothers.  This, also, helps to minimise the footprint of the southern reclamation island;

·                     For the reclamation site, where possible, the peripheral seawall will be constructed prior to the main reclamation. This reduces the overall quantity of sediment being lost from the reclamation sites as well as restricting the sediment plumes to the vessel access area where further mitigation become possible;

·                     Adopting non-dredge construction methods where practicable; and

·                     Adopting to construct the tunnel using tunnel boring machine instead of the immersed tube tunnel helps to minimise the temporary loss of fishing ground by reducing the dredging footprint and, also, the area closure around construction vessels.  In addition, as the tunnel is bored, there will be no subsequent placing of rock armour needed to protect an immersed tube tunnel and which can damage fishing nets.

9.5.1.6              As noted above, as the tunnel will be constructed using TBM, there will be no loss of seabed associated with dredging as would have been the case if trenching for an immersed tube tunnel had been proposed.  Also, the sections of tunnel at either end which are higher than the seabed will be fully enclosed within the reclamation areas and, as such, will not pose a threat to fishing gear and limited impact on capture fisheries.  As such, the tunnel overall will have minimal impact to the benthic fish prey items inhabiting the sediments.

9.5.1.7              Details of the sections of the alignment which will result in loss of permanent fishing grounds and temporary loss of fishing grounds associated with the works are presented in Figure 9.17 and summarised in Table 9.4 below.

Table 9.4      Summary of Permanent Loss of Fishing Grounds

Scheme Element (1)

Permanent Area of Fishing Grounds Lost (ha)

Temporary Area of Fishing Grounds Lost (ha)

Northern landing reclamation at Pillar Point

21.1ha(2)

 

19.8ha(4)

Southern landing reclamation at the BCF Point

25.4ha(2)

43.0ha(4)

Southern marine viaduct piers

1.2 ha
(=0.2+1.0ha)(3)

29.8ha(4)

Total

47.7ha

92.6ha

Notes:   (1) As the tunnel alignment will be constructed by TBM, disturbance and loss of the seabed along its alignment will not occur.

            (2) Based upon the footprint area to the bottom of the seawall where it intersects the seabed.

(3) Based upon 50 piers with approximately 12 x 1800mm piles each, the affected seabed (footprint of the piles) is about 0.2ha. However, as the area (1.0ha) occupied by the pile caps would not be accessible by fishing vessels, the anticipated area of fishing ground loss is higher than the seabed loss.

(4) Area estimated as provided by the engineer, the temporary works limits will be ranged between about 50 to 200m depending on type of marine works involved.

 

9.5.1.8              The details of these elements can be seen in Figures 3.2a, 3.2b and 3.7 respectively.  Based on the preferred design, approximately 21.1ha of seabed off Pillar Point, Tuen Mun and 25.4ha for the north east of the airport island reclamation and 1.2ha for the southern viaduct foundations off Tung Chung, Lantau will be permanently affected by the project.  As described previously, there is virtually no fish fry production in the western waters (Port Survey 2006) and the adult fisheries production of the area was, also, not particularly high (Figure 9.2a), with the highest production classes of 400-600 kg/ha been found around Tai O.  The waters off Tuen Mun and Tung Chung are not known to be particularly productive and the production has been recorded as being between <50-100 kg/ha, which is among the lower production classes.  As such, the approximate 21.1ha of seabed loss from the reclamation at Tuen Mun and 1.2ha from viaduct pier foundation construction in north Lantau at Tung Chung would represent a small area compared to the available 165,000ha of open waters in Hong Kong which is mostly available for fishing.  The loss of this area would represent a reduction of up to 2 tonnes (estimated based on Area × Range of adult fisheries production in the area) of adult fish production, which when compared to Hong Kong’s total annual landing of 158,000 tonnes (2008 value which represents the landing statistics by Hong Kong fishing vessels operating both within and outside Hong Kong), would not be considered significant. 

9.5.1.9              With respect to the southern reclamation for the portal off the north-east of the airport island, the fisheries production in this area has been shown to be in the moderate class of 200-400 kg/ha. Based on this production rate, the proposed reclamation of around 25.4ha could potentially lead to a loss of around 5-10 tonnes adult fisheries production.  This represents a small fraction of Hong Kong’s total annual landing of the estimated 158,000 tonnes (2008 value which represents the landing statistics by Hong Kong fishing vessels both within and outside Hong Kong) and the loss of this area of fishing ground would unlikely cause a noticeable reduction to the overall Hong Kong fish catches.  

9.5.1.10          However, the potential localised impacts cannot be neglected as the Brothers has been identified as one of the local fisheries hotspots, although it must be emphasised that the preferred alignment will avoid the core areas at the Brothers (see Section 2).  The total loss of local fishing grounds from all elements of the TM-CLKL project would be 47.7ha but this remains relatively small and not significant when compared to available area with the North-western waters.  The equivalent production loss of adult fisheries would be in the region of 5-12 tonnes, which again would not be considered significant compared to the Hong Kong landing of 158,000 tonnes.   

9.5.1.11          As detailed in Table 9.4, there may also be some temporary loss of fishing grounds associated with the works for the marine viaduct and the reclamations.  Based upon a works area of about 50m wide, a maximum of 29.8ha would be temporarily unavailable for the duration of the viaduct works, programme to be 14 months.  For the reclamations, based upon a works area of 100-200m around the sites, a total of 62.8ha would be temporarily unavailable for the duration of the reclamation works of 2 to 3 years.  This total temporary loss of 92.6ha would result in a short-term temporary loss of adult fisheries production of up to 37 tonnes (assuming that all the area to be lost would have the higher production class of 200-400kg/ha), which are small fraction of the total Hong Kong landing (158,000 tonnes) and would be for a short duration only.  Also, as fishermen are able to fish in the whole of Hong Kong waters without restriction, except at special areas like marine park, reserves or major navigation channels, the temporary un-availability of these fishing grounds in the North-western waters would not represent an impact in real terms of fisheries catches but be more of an issue of the need to alter usual fishing patterns.

9.5.1.12          In summary, while some permanent loss of fishing grounds will occur and there will be some minor impacts at local level, given the magnitude of the loss, the residual impacts associated with the associated with the TM-CLKL are expected to be small and acceptable.

Disturbance to Fishing Operations

9.5.1.13          The Port Survey 2006 has indicated that small vessels, such as sampans, are mainly used by fishermen in the study area.  Given that these vessels are highly mobile and the construction vessels will be largely concentrated in certain areas, it is not expected that the construction marine traffic will significantly interfere with the fishing activities of the small vessel operators in this area.  Thus, impacts from the reclamation/dredging operations to small boat operators are likely to be localised around the construction areas and are not likely to range wider.  The distribution range of the fish involved will, also, generally be wider than the works area and opportunities will still exist to catch the fish outside the study area. As the area is not the major operating area for the large trawling vessels (>15m), impacts to them would also be limited.

Deterioration of Water Quality

9.5.1.14          The deterioration of water quality, through seabed disturbance and the release of suspended solids into the water column, has the ability to have indirect effects on fisheries if not controlled.  As discussed above, construction of the reclamation will adopt a minimal dredge approach where possible which will help minimise the magnitude of any impacts.  The key potential dredging and backfilling related water quality deterioration will be from the reclamation works for the northern and southern landfalls, with the sediment removal for the viaduct piers being undertaken from within a steel casing which will result in negligible loss of sediments. 

9.5.1.15          The water quality modelling results are detailed in full in Section 6.  These results show that the key sediment losses will actually result from the combined HKBCF/ TM-CLKL reclamation east of the airport island. Notwithstanding, with the implementation of extensive mitigation it the form of silt curtains around each grab dredger and, also, encompassing the main HKBCF/TM-CLKL southern landfall works areas, impacts can be reduced to within acceptable levels.

9.5.1.16          The predicted maximum extent of sediment plumes and the potential maximum elevation together with the AFCD’s 2006 port survey result of fisheries production are presented in Figures 9.5 to 9.16 for each of the modelling scenario times, and both with and without the (1+1) silt curtain system mitigation in place. It should be noted that, the maximum plumes envelopes shown only indicate the potentially highest levels at any one place without any indication of the time and frequency such a maximum elevation would occurs.  The frequency of the SS levels exceeding the WQO criteria (generally below 10 mg/L), and the criteria for the protection fish of 50 mg/L are tabulated in Tables 6.21 to 6.26 for representative moderate productive areas such as the Sha Chau and Lung Kwu Chau Marine Park (WSR 10), Sham Shui Kok (WSR 45c), the Tai Mo To (WSRs 46 and 49) and should be referenced for more exact value of predicted maximum SS elevation and frequency of WQO exceedances.  It is clear from these tables that the predicted maximum SS elevation at these points are well below the 50 mg/L criteria for the protection of fishes even without mitigation.

9.5.1.17          With reference to Figures 9.5 to 9.16 and the fisheries production grid with the maximum sediment plume envelope, it is clear that the within the north Lantau waters, important fisheries production grounds are at the Sha Chau and Lung Kwu Chau Marine Park, north-west of Tai O and also the Brothers, with the east of Hong Kong waters being generally more productive than the western waters (left panel of the figures). However, project related sediment plumes are predicted to be confined to the more sheltered East Tung Chung Bay and often the plumes are confined to within the project site (right panel of the figures).  While plumes can extend outside the project site, the maximum level are generally constrained to less than 50 mg/L within 500m of the site and high levels of elevations are, also, not frequently predicted.  Without mitigation, plumes that disperse into the Brothers-Sham Shui Kok area are generally below 10 mg/L, although higher levels of around 30 mg/L could be present in the bottom levels.

9.5.1.18          Figures 9.5 to 9.16 also demonstrate that with the implementation of the extensive (1+1) silt curtain system which effectively encloses the entire project sites, the SS elevation band at around 500m of the site would be largely reduced to less than 30 mg/L.  Nonetheless, some transient exceedances of the WQO will remain in the close vicinity of the works area but these will be in areas where fishing operations will not be continuing during the construction phase as the area about 100m to 250m around the reclamation will be allocated as works areas.  In addition, the sediment has been shown to be not contaminated overall (Section 6.3.5, Appendix D1) and, as such, significant impacts associated with contaminants getting into the food chain would not be expected.  This is also, demonstrated by the assessment in Section 6.9.4 and Table 6.28, where, even using worst case estimations, the predicted maximum increases in the sediment borne contaminants will be well within the criteria for the protection of marine life, except in the immediate vicinity of the works area. This assessment approach is highly conservative and would not underestimate the risk.  

9.5.1.19          It is likely that fish will generally avoid disturbed areas (as fish are typically highly mobile) or adapt to local conditions (i.e., the high suspended sediment loads carried in the water column and/or the re-suspension of soft-bottom sediments characteristic of the North-western waters).  Furthermore, lethal impacts from suspended solids are not usually induced in fish until ambient concentrations reach 1,000 mg l-1 and it is notable that a recent study with a local fish species, the mangrove snapper (Lutjanus argentimaculatus) showed that extremely high suspended solid concentrations failed to induce toxicity.  The mangrove snapper tolerated high total suspended solid loadings and the 48-h NOEC (no observable effect concentration) was 5,000 mg l-1 (CityU, 2001). On cessation of the construction phase activity, it is likely that fish will rapidly recolonise the area.  Impacts are, therefore, not likely to be significant as they will be highly localised, reversible and controlled with proper mitigation measures.

9.5.1.20          Dredging operations using a variety of equipment including trailer dredgers and grab dredgers, will result in plumes of sediment throughout the water column.  However, as the flows around the main HKBCF/TM-CLKL works areas are relatively low (Section 6.8.23 and Appendix D6), the plumes are expected to settle out rapidly.  The highest levels of sediment are, therefore, predicted to occur in the bottom layers (Tables 6.21, 6.23 and 6.25; Figures 9.5, 9.7, 9.9, 9.11, 9.13 and 9.15).  This bottom layer is naturally subject to large variability in suspended sediment conditions as a result of natural processes of sediment deposition and erosion.  Demersal species inhabiting these waters are consequently tolerant to such variability in suspended sediment conditions.  Notwithstanding, with the application of mitigation measures, suspended sediment concentrations within all layers would generally be localised to within or very close to the works area (Section 6.9 and Tables 6.22, 6.24 and 6.26; Figures 9.6, 9.8, 9.10, 9.12, 9.14 and 9.16).  There are a few short lived plumes in the immediate vicinity which would be above ambient although these would be expected to be very localised and within the natural variability experienced in the North Western waters.  Thus, both pelagic and demersal species are unlikely to be significantly impacted.  Spawning activities are, thus, also, unlikely to be disrupted.

9.5.1.21          Significant impacts to fisheries resources in the study area are not expected based upon the fact that the mitigation measures recommended to protect water quality sensitive receivers would, also, be adequate to minimise adverse impacts to fisheries resources.

Disturbance to Mariculture Zones

9.5.1.22          The mariculture zone at Ma Wan is sufficiently distant from the works (~10km) and the modelling results show that no impacts at the Ma Wan FCZ nor the Deep Bay Oyster Beds (at about 15km away) will occur (Tables 6.21 to 6.25 and Figures 9.5 to 9.16) Construction phase dredging works will, therefore, not affect the operations of these facilities and significant impacts are not predicted. 

Artificial Reefs

9.5.1.23          The nearest AR at the Chek Lap Kok Marine Exclusion Zone is located approximately 1km away from the proposed TM-CLKL alignment (Figure 9.1) but only a few hundred meters away from the HKBCF.  This AR was implemented in 2000 and has a footprint of 1,200m2 and an overall area of approximately 3600m3.  While the reef is outside the footprint of the TM-CLKL and the HKBCF, the results of the water quality assessment show that low frequency of exceedances of the suspended solids WQO will occur in 2011 scenario at this location (Table 6.24), even with the (1+1) silt curtain system mitigation measures applied.  Maximum mitigated SS elevations are predicted to be 6.1 mg/L (depth-averaged) in the wet season slightly above the calculated 3.7 mg/L WQO, although exceedances are only predicted for about 4 % of the wet season period and no exceedances are predicted during the dry season time.  It should be noted that the highest background SS level measured among nearby EPD monitoring stations (NM1, NM2 and NM3) during 2006 was 21.3mg/L at NM2 which is 14.9mg/L above its station mean of 6.4 mg/L.  Hence, the maximum mitigated SS elevations are not predicted to be higher than natural variations.  As the reef serves as a refuge for fish and aids fish resource recovery, impacts to the AR would be a minor to moderate impact, however, requiring mitigation.  

9.5.1.24          However, it is jointly proposed by the TM-CLKL and HKBCF projects that this AR will be reprovisioned to mitigate against the predicted impacts from the reclamation works.

9.5.2                    Operational Phase

9.5.2.1              The potential fisheries impacts during the operational phase of the Project would not included any direct impacts but would be restricted to potential indirect impacts associated with changes in hydrology and tidal flows in adjacent waters, discharge of runoff from road surface and any disturbance to fishing vessels from the operations of the TM-CLKL.  The following presents an evaluation of the potential impacts identified above.

Change of Hydrology and Tidal Flow

9.5.2.2              It is expected the TM-CLKL may induce some small changes to the hydrology and tidal flow leading to possible impacts to the fisheries resources.  It should be emphasised that, as the HKBCF and HKLR will be constructed concurrently with the TM-CLKL, the three projects have been treated as combined for the purposes of the water quality modelling.  The potential impacts associated with TM-CLKL (and indeed, the HKLR) are expected to be relatively small compared with the much larger reclamation (138ha) proposed for the HKBCF.  However, the hydrodynamic and water quality modelling results have confirmed that no significant large scale changes to these factors will occur as a result of the project (Sections 6.8.2 and 6.8.3). The modelling results, detailed in Appendix D, but key physiological parameters results summarised in the Tables 6.18 (temperature) and 6.19 (salinity).  In general, only very small changes in depth-averaged monthly temperatures and salinity are predicted and the predicted changes are within the WQOs of ±2°C for temperature and 10% of change for salinity, although technically it should be noted that these two WQO criteria are applied to waste discharges.  The natural annual fluctuation of temperature and salinity in the North-western WCZ, as indicated by the inter-year difference of EPD’s station in 2006 and 2007 (Tables 6.6a and 6.6b), were already shown to be in the range of 0.2 °C to 0.7 °C for temperature and -0.7ppt to -1.5ppt for salinity, which are comparatively larger than the predicted change related to the proposed project reclamations.  Hence, although small localised changes are predicted, it can be concluded that these small changes attributable to the proposed reclamation would unlikely induce significant ecological impacts to the species in the study area which are already acclimatised to such variations. Therefore, the implications to fisheries resources and fisheries will not be significant.

9.5.2.3              With respect to the Ma Wan Fish Culture zone (WSR 20), no significant changes are predicted and the key water quality parameters are also presented in Tables 6.18 and 6.19 and the results clear demonstrate no adverse significant impacts to Ma Wan Fish Culture Zone are anticipated.

Surface Runoff

9.5.2.4              Areas of potential water quality impacts during the operational phase will largely comprise paved area run-off containing suspended solids onto which hydrocarbons and heavy metals, principally lead, copper, zinc and iron, may be adsorbed.

9.5.2.5              Potential adverse impacts from runoff from the paved road surfaces (including the carriageway and toll plaza area) can result from storm water carrying dissolved and particulate material from degradation of the road surface and tyres and from normal operational fuel and oil loss from vehicles.  The most vulnerable time will be during the first flush of rain. Contaminants present in the normal operational runoff will, by their chemical nature, be strongly adsorbed onto particulates present.

9.5.2.6              Stormwater drainage systems will be provided to collect stormwater from the carriageway surfaces.  In respect of the roads on land, the stormwater will enter into gullies along the kerb lines and the gullies will be fitted with sumps to trap silt and grit prior to discharging the stormwater into the stormwater drainage systems.  The drainage systems will eventually discharge the stormwater into the sea at discrete locations.  A similar system will be provided along the marine viaduct, with sump traps being proposed to be built into the deck structure. The collected stormwater will discharge into the sea at the column locations.

9.5.2.7              The operational phase run-off from the reclamation areas has been included in the pollution load inventory for the water quality modelling (Section 6.7.3.12) and the results of the operational phases water quality assessment (Section 6.8.3) showed that no significant effects of water quality were expected during the operational phase.

Marine Traffic

9.5.2.8              The Marine Traffic Impacts Assessment has concluded that there would not be any notable changes to marine traffic vessel numbers or patterns in the area as a result of the implementation of the project. As such, impacts to fishing operations are not expected to be affected.

Accidental Spillage

9.5.2.9              There is the potential risk to fisheries due to the chemical or oil spillages arising from a vehicle accident during operation of the project.  While Dangerous Goods (DG) vehicles of Categories 1, 2 and 5 are prohibited from using the tunnel, tankers (DG Cat 5) will be allowed to use the southern marine viaduct and in the event of an accident with such a tanker, there is the possibility for the spillage of oil or chemicals.  In this case, the integrated permanent road drainage system discharge any spilt materials into the marine environment, although the 0.8m profile barrier, which has been proposed along the marine viaduct, will prevent vehicles from leaving the road.  The majority of Hong Kong road tanker transport will be of fuels, such as petrol, deisel and possibly LPG and LNG, together with some liquid chemicals.

9.5.2.10           By far the most serious environmental consequences of a major fuel spill would occur in the early stages when the split material may form extensive slicks on the sea surface.  Direct contact with the oil or chemicals may affect many types of marine organisms. 

9.5.2.11          A typical oil or chemical tanker capacity is between 10-12m3 and in the event of an accident, the emergency call-out procedure in case oil/chemical spillage on the road would be rapidly implemented to clean-up and contain any spill.  Assuming all the spill did enter the marine waters, as the fuels all have a specific gravity of less than 1 (water), they would all float on water.  In respect of any petrol and diesel, the natural process of the spill spreading would reduce its thickness and allow the process of wind and wave action in breaking up the spill to increase as well as evaporation and dissolution.  Dispersion of any spill will occur more rapidly in high energy waters which occur along the majority of the viaduct length.  Both LPG/LNG have very low boiling points and would rapidly vapourise.  Inorganic chemicals such as acids and alkalis, may not evaporate as quickly but would rapidly be diluted.  The possible quantity of material is very small and the dilution and dispersion factor of the receiving waters so large (the tidal volume would be estimated to be in the range 80,000 to 200,000m3 depending upon the tide type) in comparison.

9.5.2.12          Both fish and crustaceans are able to metabolise petroleum hydrocarbons (Capuzzo and Lancaster, 1981; Whipple et al., 1981; Brzorad and Burger, 1994) relatively efficiently. For example, during the 5 years EM&A programme for the contaminated mud disposal site at East of Sha Chau (Meinhardt under preparation) between 2001-2005, 2680 fisheries samples (including fish, prawn and shrimps, crabs and squids) were analysed for contaminants including PCBs and PAHs. The result indicated that PCBs and PAHs were below analytical detection limits and the average detection frequency was only 1.7% indicating these contaminants were generally not bio-accumulated.

9.5.2.13          In addition, research into the impact of a major oil spill on marine ecological receivers and fisheries following a spill of 4000 tonnes of heavy marine diesel in Hong Kong (Ap Lei Chau) in 1973 showed that local fish species were able to metabolise the oil (ambient aromatic fraction concentration calculated at 45-60 mg l-1; Spooner, 1977). Although mortality was evident in some fish held in cages (10% mortality was observed in the stock held in the fish cages at Sok Kwu Wan, Lamma Island within one month of the spill) that were unable to avoid the oil and some highly territorial species (such as damsel fish and porcupine fish) were killed (Spooner, 1977), the catastrophic impacts recorded in the fish farming operation were short-lived and recovery was rapid (nine months), following dissipation of oil in the water column and restocking of fish in the cages (Spooner, 1977).  Although short-term impacts to some fish have been reported in Hong Kong due to major spills of heavy oils, given the fact that refined fuels are transported by road tanker in Hong Kong and the very small quantities that would enter the marine environment should an accident occur, the spill is predicted to dissipated and disappear very rapidly.  Hence, impacts to free swimming fish from a small chemical or oil spill are predicted to be insignificant  Also, as the viaduct is many kilometres from the fish culture zone at Ma Wan, the spill would be expected to be largely diluted and evaporated and not affect this resource.  

9.5.3                    Summary of Impacts

9.5.3.1              A summary of the potential impacts in the construction and operational phase are provided in Table 9.5 below.

Table 9.5         Summary of Impacts

General Impact

Potential Impact

Severity of Impact

Mitigation Required

Construction Phase

Loss of Fishing Grounds

Permanent loss of 48ha from TM-CLKL reclamations affecting fishing grounds.  No affects to spawning or nursery areas or mariculture activities.

Minor

 

No

(see cumulative impacts)

 

Temporary loss of 92.6ha associated with works area for the marine viaduct and reclamations for period of 2 to 3 years.

Insignificant

 

No

Deterioration of Marine Water Quality

Impacts from dredging and backfilling activities for southern landfall reclamation affecting Artificial Reef in Marine Exclusion Zone 3(1)

Minor to Moderate

 

Yes(1)

 

 

Temporary impacts from dredging and backfilling activities for all marine works on the fishing grounds.

Insignificant

No(2)

 

 

 

 

Disturbance to Fishing Operations

Temporary disturbance to fishing operations from construction vessels.

Insignificant

 

No

 

Operational Phase

Change to water flows

Changes to flows that could affect water quality and fishery resources

Insignificant

No

Deterioration of Marine Water Quality

Impacts relating to surface runoff from paved areas.

Insignificant

No but silt and grease traps provided

Accidental spillage

Insignificant

No

Disturbance to Fishing Operations

Changes to marine traffic volumes and patterns in the area that would affect fishing operations

Insignificant

No

Note:          (1) Impacts are in conjunction with the HKBCF project and the mitigation/compensation is recommended as a joint measure. (2) Assumes water quality mitigation will be implemented.

9.6                          Mitigation and Enhancement Measures  

9.6.1.1              The permanent loss of fishing grounds for the TM-CLKL are not considered significant as the area lost is relatively small overall.  However, it is proposed that, in compensation for the construction impacts on the AR in the airport exclusion zone from the TM-CLKL and HKBCF projects, a further AR is deployed in an area where fishing activities are prohibited.  The existing reef will be left in place and it may recover over time once the construction works have been completed, however, this is not being assumed in determining the compensation.  Thus, in order to mitigate for impacts from the TM-CLKL, HKBCF and HKLR projects, the replacement AR would be expected to be of an equivalent size as that lost, that is 1,200m2.  However, further compensation for the loss by deploying an additional 2,400m2 AR as an enhancement measure is, also, proposed.  The overall size, comprising both mitigation and enhancement measures would be on a size ratio of 1:3 to the existing one, that is a total area of 3,600m2 and a volume of 10,800m3.  The new AR which would have the double role of replacing the AR to be affected but, also, will have some beneficial effects on the fishing resources in the area.  A specification for the deployment of the AR will need to be prepared during the detailed design phase, as discussed further in the marine ecology section.  In addition, as described in Section 6.10, a series of mitigation measures to protect the water quality will, also, reduce any impacts to fisheries in the area.    

9.6.1.2            In addition, based upon the upon potential impacts to dolphins, the Government has made a firm commitment to seek to designate the Brothers Islands as a marine park for enhancing the CWD habitat in accordance with the statutory process stipulated in the Marine Parks Ordinance.  With the establishment of the new marine park and implementation of management measures, the fisheries resource of the area will be better managed and together with the other ecological enhancement measures, will enhance the long-term sustainability of the fisheries industry in the area.  In addition, based upon the upon potential impacts to dolphins, the Government has made a firm commitment to seek to designate the Brothers Islands as a marine park for enhancing the CWD habitat in accordance with the statutory process stipulated in the Marine Parks Ordinance.  With the establishment of the new marine park and introduction of licence control, the fisheries resource of the area will be better managed and together with the other ecological enhancement measures, will enhance the long-term sustainability of the fisheries industry in the area.

9.6.1.3              A summary of the mitigation measures proposed for the significant impact noted in Table 9.5 above are presented in Table 9.6 below.

Table 9.6 Summary of Mitigation for Fisheries

Impact

Significance

Mitigation

Loss of Artificial Reef

Minor to Moderate

Deployment of new AR(1)

Note (1): Mitigation proposed jointly by the TM-CLKL and HKBCF projects.

9.7                          Cumulative Impacts

9.7.1.1              There are many projects being proposed to be implemented in the same study area and those that are concurrent to the TM-CLKL construction may cause cumulative impacts to the fisheries in the study area.  Section 6 of this EIA on Water Quality has undergone a comprehensive quantitative assessment of the construction and operational phase impacts.  As the HKBCF, HKLR and TM-CLKL project are linked and will be constructed together, these have been assessed as effectively one project, with the other projects being considered as cumulative.

9.7.1.2              The water quality assessment has concluded that based on the implementation of the TM-CLKL+HKBCF+HKLR projects together, no sensitive receivers are predicted to be impacted with the application of mitigation measures. The water quality assessment, also, considered the concurrent construction, not only of the TM-CLKL+HKBCF+HKLR, but also the other projects detailed in Table 6.13. The results of the cumulative modelling indicate that the sediment plumes arise from the project (TM-CLKL+HKBCF+HKLR) generally do not coincide with other plumes except over a small area to the north-west and east of the project site (Section 6.12). Sediment plumes are not predicted to reach Ma Wan FCZ and, hence, no impacts to this FCZ are anticipated. With the concurrent projects, however, low to moderate WQO SS exceedances (2 to 9% of the time; Appendix D8 to D10) are predicted at the AR to the north–east of the airport.  Notwithstanding,  the cumulative impacts to this AR will be compensated by the replacement of the AR of an equivalent size as that lost, that is 1,200m2 and the further compensation for the loss by deploying an additional 2,400m2 AR as an enhancement measure.

9.7.1.3              In addition to the construction phase impacts, projects which comprise land reclamation can result in further temporary or permanent loss of fisheries habitats.  A review of the concurrent projects in the study area is provided in Appendix A2 of this report.  In summary, the following projects detailed in Table 9.7 below are relevant to the marine environment during the construction and operational phases.

Table 9.7      Summary of Possible Concurrent Projects which Could Result in Cumulative Impacts during Construction and Operation

Proposed Development

Impacts to be Considered

Assumed Permanent/

Temporary Loss

Assumed Implementation

Kwai Tsing Container Basin Dredging

Construction and Operation

Permanent:

0ha (no structures above seabed anticipated)

 

Temporary:

415ha (estimated based on the dredging footprint) (3)

2010 to 2013

Proposed Lantau Logistics Park (LLP) and possible LLP extension or other compatible uses

Construction (72ha development)

Operation (72ha and 40ha developments)

Permanent:

72ha+40ha for Phase 1 and 2

 

Temporary:

58ha (estimated assuming 100m works limit for Phase 1. Phase 2 is not relevant)

2010-2012 for proposed LLP.

No programme for LLP extension but assumed in place for operational assessment.

Hong Kong Zhuhai Macao Bridge (HZMB) – Hong Kong Link Road (HKLR)

Construction and Operation

Permanent:

27ha of reclamation required and about 3ha for marine viaduct piers

 

Temporary:

213ha

2010-2015

HZMB Hong Kong Boundary Crossing Facilities (HKBCF)

Construction and Operation (138ha of reclamation required).

Permanent:

138ha

 

Temporary:

88ha

2010-2015

Road P1, Sham Shui Kok to Sunny Bay

Operation (based on assumed programme to be operational in 2026)

Permanent:

9.5ha

 

Temporary:

Not relevant as construction shall not be concurrent with TM-CLKL

After 2026

Future Tung Chung East and West Development

Operation (construction to begin after completion of the TMCLKL+HKBCF)

Permanent:

110ha and 50ha for east and west respectively

 

Temporary:

Not relevant as construction shall not be concurrent with TM-CLKL

2016-beyond 2017

Existing Contaminated Mud Disposal Facility at East Sha Chau

Operation

Permanent:

0ha (no structures above seabed anticipated)

 

Temporary:

101ha (based on the footprint of the mud pit)

Current

Proposed Contaminated Mud Disposal Facility at East of Sha Chau and South of Brothers

Construction and Operation for Target Year of 2011

Permanent:

0ha (no structures above seabed anticipated)

 

Temporary:

270ha (estimated based on the footprint of the mud pits)

2011(2)

Mud Disposal Facility at North Brothers

Operation (when disposal operations might begin is not known but it is possible this facility could be operational after 2009)

Permanent:

0ha (no structures above seabed anticipated)

 

Temporary:

290ha (estimated based on the footprint of the pits)

Reopening at 2009

Notes

1: Construction projects outside Hong Kong waters (e.g., Tonggu Channel maintenance dredging and the mainland section of HZMB) were not included in the assessment as these projects will not affect the availability of fishing grounds in Hong Kong.

2: It is understood that CEDD is reviewing the proposed CMP at South Brothers and until the review is completed, the worse case scenario assuming implementation at 2011 has been adopted in this study.

3. Because the works are at major navigation areas, it is unlikely the entire dredging footprint will be closed simultaneously and thus additional area from works limit not assumed.

9.7.1.4              Assuming the HKBCF (138ha), HKLR (27+3ha), TM-CLKL (48ha) and Phase I of the LLP (72ha) are all constructed at the same time, a total of 288ha of fishing area will be lost in the short-term in the North-western waters.  This loss could increase in future with the implementation of, Phase 2 of LLP (40 ha) the Future Tung Chung East and West Development (160ha) (after 2017) and Road P1 (9.5ha) (after 2026) giving a total of about 498.5ha.  As such, the potential cumulative permanent fishing ground loss of about 500ha is much larger than the 48ha predicted for the TM-CLKL alone especially considering that much of the affected areas are at relatively less productive areas within the North-western waters (including the northern reclamation and southern viaducts of TM-CLK, LLP and Future Tung Chung East and West Development).  The TM-CLKL will not trigger any cumulative impacts by its implementation as they will occur without this project being constructed.  In addition, as detailed in Table 8.32, the TM-CLKL habitat loss area is relatively small overall and the contribution of the TM-CLKL alone to the cumulative impacts is expected to be minor.

9.7.1.5              For the cumulative fishing ground loss, a conservation approach has been adopted. As the fisheries production within the North-western waters range from <50 to 400-600kg/ha, the assessment has assumed that all the area to be lost would have the higher production class of 400-600kg/ha. The potential cumulative permanent loss of fishing ground (about 500ha) as compared to the whole Hong Kong waters (165,000ha) which is mostly available for fishing, is relatively small and represents a potential loss of about 200-300 tonnes production, which would not be considered significant compared to the Hong Kong landing amount of 158,000 tonnes in 2008 especially when considering the fact that the annual production from within the North-western water control zone are mostly in the class of 100-200 kg/ha and 200-400 kg/ha and the proposed future projects are mostly along the less productive coastline. Hence, while a worse case scenario is assumed in the assessment to give an estimate of the maximum potential impacts, the likelihood of the worse case scenario is relatively remote and would unlikely happen in short-time. 

9.7.1.6              In addition to the above permanent losses, temporary losses in fishing grounds could result from dredging and filling activities for tentative projects including the HKBCF (88ha) and HKLR (213ha), LLP (58ha) , Kwai Tsing Basin (about 415ha), the operation of the existing CMP at East Sha Chau (101ha), the construction/ operation of the Proposed Contaminated Mud Disposal Facility at East of Sha Chau and South of Brothers (270ha assuming all pits were operating at the same time which would not be the case) and Mud disposal Facility at North Brothers (about 290ha).  These projects would, also, be potentially concurrent to the 92.6ha temporary losses for the TM-CLKL. However, the cumulative temporary fishing ground losses are much larger than those predicted for the TM-CLKL alone, and with the TM-CLKL making only a limited contribution to the total amount.  It should be noted also, that these temporary losses represent a short-term un-availability of fishing grounds to fishing operations rather than loss of fisheries resources.  As fishermen are generally free to fish in the whole of Hong Kong waters without restriction, except at special areas like marine park, reserves or major navigation channels, the temporary un-availability of fishing grounds in the North-western waters would not represent an impact in real terms of fisheries catches especially when considering that some of the potentially affected areas like the Kwai Tsing Basin Kwai Tsing container basin and the northern reclamation and southern viaducts of TM-CLK, LLP and Future Tung Chung East and West Development are at the relatively less productive area and are not the major fishing grounds.  However, while the cumulative temporary loss of fishing grounds in this area are not expected to cause significant impacts to overall fish catches, the fishermen in the local area who habitually fish in these areas would be affected due to the need to change their usual fishing patterns and areas which could affect the time usually spent on fishing trips and hence, affect the operating costs incurred.

9.7.1.7            As noted above, the deployment of a new AR, three times the size of the AR at the airport exclusion zone to be affected, is recommended as mitigation and further additional enhancement.  While this area could be restricted to fishing operations, it would have the benefit of acting as a nursery and protection area for fish resources in the area and, ultimately, could benefit the fisheries industry in the area.  The proposed designation of a marine park at the Brothers, as noted above, will, also, help to enhance the long-term sustainability of the fisheries industry.  As noted above, the deployment of a new AR, three times the size of the AR at the airport exclusion zone to be affected, is recommended as mitigation and further additional enhancement.  While this area could be restricted to fishing operations, it would have the benefit of acting as a nursery and protection area for fish resources in the area and, ultimately, could benefit the fisheries industry in the area.  The proposed designation of a marine park at the Brothers, as noted above, will, also, help to enhance the long-term sustainability of the fisheries industry.

9.7.1.8              In addition, in order to address the cumulative impacts from all the projects and compensate for the cumulative Chinese White Dolphin and fisheries habitat loss, the Government has made a firm commitment to seek to designate the Brothers Islands as a marine park for enhancing the CWD habitat. While fishing operations within marine park would be than subject to licence control, it would have the benefit as acting as a nursery and protection area for fish resources in the area and, ultimately, would benefit the fisheries resources and industry in the area. The process for the designation of the proposed marine park would proceed after the completion of these three projects. A feasibility study will be conducted to confirm the details of the proposed marine park before the commencement of the statutory procedures as stipulated in the Marine Parks Ordinance.

9.8                          Residual Impacts of the TM-CLKL

9.8.1.1              Some residual impacts are predicted for permanent habitat loss associated with the TM-CLKL and cumulatively with the potential concurrent projects in the north western waters would occur without mitigation.  The recommended mitigation measures include extensive silt curtain system to minimise water quality deterioration during the construction stage and the deployment of the artificial reef.  

9.8.1.2              The following factors should be considered in determining the residual impacts associated with the project: 

·               implementation of the project is not predicted to significantly affect fisheries resources;

·               the majority of the predicted impacts are temporary and reversible;

·               the geographic extent of the potential impacts on fisheries and fishing grounds from the TM-CLKL construction will not be large;

·               the water quality mitigation measures proposed will confine the construction stage influence of the TM-CLKL to a small area;

·               the TM-CLKL itself will not trigger cumulative impacts;  

·               the contribution from the TM-CLKL to cumulative impacts would be small overall; and

·               the provision of compensatory and additional artificial reef and proposed marine park will compensate for impacts on the fisheries resources due to the permanent loss of fishing ground associated with the project.

9.8.1.3              Based upon the above, the application of the above mitigation and enhancement measures are considered sufficient to mitigate the predicted impacts from the TM-CLKL and, therefore, overall, no significant adverse residual impacts are predicted for either the construction or operational phases of the project.

9.9                          Environmental Monitoring and Audit

9.9.1.1              A monitoring and audit programme will be designed to detect any unacceptable impacts to water quality as required (to be discussed in the Water Quality Assessment and the EM&A Manual) and this will also ensure adequate protection of fisheries resources in the study area.  As such, not specific fisheries EM&A is recommended.

9.10                      References

AFCD (2007). Department Annual Report 2006-2007. Agriculture, Fisheries and Conservation Department, Hong Kong Government of the SAR.

AFCD (2008). Department Annual Report 2007-2008. Agriculture, Fisheries and Conservation Department, Hong Kong Government of the SAR.

AFCD (2009a). Agriculture, Fisheries and Conservation Department, Hong Kong Government of the SAR. Fisheries: Capture Fisheries. Retrieved May 15, 2009, from http://www.afcd.gov.hk

AFCD (2009b). Port Survey 2006. Agriculture, Fisheries and Conservation Department, Hong Kong Government of the SAR. Retrieved May 15, 2009, from http://www.afcd.gov.hk

Binnie Consultants (1995). REMOTS and Grab Survey to Assess Benthic Recolonisation following backfilling at East of Sha Chau (East) Marine Borrow Pit. Prepared for CED.

CityU (City University of Hong Kong) (2001). Agreement No. CE 62/98, Consultancy Study on Fisheries and Marine Ecological Criteria for Impact Assessment, Final Report, for the Agriculture, Fisheries and Conservation Department, HKSAR Government.

EPD (2006), 20 years of marine water quality monitoring in Hong Kong.

ERM (1998). Fisheries Resources and Fishing Operations in Hong Kong Waters. Prepared for AFCD.

ERM (2005). Detailed Site Selection Study for a Proposed Contaminated Mud Disposal Facility within the Airport East/East of Sha Chau Area. Environmental Impact Assessment and Final Site Selection Report. Prepared for the Civil Engineering and Development Department, Government of HKSAR.

Hyder (1998).  Supplement EIA for the Proposed Sand Extraction from the Brothers Marine Borrow Area. Prepared for CED.

Meinhardt (2006a). Environmental Monitoring and Audit for Contaminated Mud Pit IV at East Sha Chau (2000-2005).  4th Annual Review Report. Prepared for the Civil Engineering and Development Department, Government of HKSAR.

Meinhardt (2006b). Environmental Monitoring and Audit for Contaminated Mud Pit IV at East Sha Chau (2000-2005).  19th Quarterly Report for November to December 2005. Prepared for the Civil Engineering and Development Department, Government of HKSAR.

Meinhardt (2006c). Environmental Monitoring and Audit for Contaminated Mud Pit IV at East Sha Chau (2000-2005).  18th Quarterly Report for August to October 2005. Prepared for the CEDD.

Meinhardt (2006d). Permanent Aviation Fuel Facility Environmental Impact Assessment Report: Prepared for Airport Authority Hong Kong.

Mouchel (2001). Environmental Monitoring and Audit for Contaminated Mud Pit IV at East Sha Chau. First Quarterly Report, May to July 2001. Prepared for CED.

Mouchel (2002). Environmental Assessment Study for Backfiling of Marine Borrow Pits at North of the Brothers. Environmental Assessment Report. Prepared for the Civil Engineering Department, Government of HKSAR.

Mouchel (2004). Hong Kong- Zhuhai- Macao Bridge: Hong Kong Section and the North Lantau Final 9 Month Ecological Baseline Survey Report. Prepared for the Highways Department, Government of HKSAR.

Mouchel (2005a). Environmental Monitoring and Audit for Contaminated Mud Pit IV at East Sha Chau (2000-2005).  4th Annual Risk Assessment Report. Prepared for the Civil Engineering Department, Government of HKSAR.

Mouchel (2005b). Environmental Monitoring and Audit for Contaminated Mud Pit IV at East Sha Chau (2000-2005).  16th Quarterly Report for February to April 2005. Prepared for the Civil Engineering and Development Department, Government of HKSAR.