6.3 Legislation, Standards & Guidelines
6.5 Ecological Baseline Profile
6.6 Construction Phase Impact Assessment
6.7 Operational Phase Impact Assessment
6.8 Mitigation Measures & Best Practice
6.9 Residual Impact Assessment
6.10 Environmental Monitoring & Audit Requirements
6.11 Conclusions & Recommendations
6.1.1.1 This section presents the approach to and the findings of the pelagic ecology baseline assessment and the Project impact assessment. Pelagic ecology concerns open sea habitat, species and communities, and for the purposes of this EIA Study also includes reef fishes.
6.1.1.2 The aim of the pelagic ecological impact assessment is to present representative baseline ecological conditions within the Study Area and evaluate these against potential impacts from Project development with a view to protection and enhancement of the natural environment.
6.2.1.1
The pelagic ecological
assessment has been undertaken in accordance with the criteria and guidelines
in Annexes 8 and 16 respectively of the EIA-TM, and with reference to the
requirements of Clause
6.2.1.2 The key objectives are as follows:
·
Review the
findings of relevant studies/surveys and collate the available information
regarding the ecological characters of the assessment area;
·
Evaluate
information collected and identify any information gap relating to the
assessment of potential ecological impact;
·
Conduct marine
mammal field survey of at least 12 months covering 4 seasons to fill
information gaps identified in Section
·
Establish the general
ecological profile of the Study Area taking into account seasonal variations,
and describe the characteristics of each habitat found. Major information shall
include inter alia the types / locations of habitats and species of
conservation interest such as marine mammals, in particular finless
porpoises;
·
Identify and
quantify as far as possible impacts or disturbance (e.g., physical injury,
underwater noise) to marine mammals in particular finless porpoises during
construction (e.g., dredging of turbine foundations, cable installations, pile
driving for installation of turbine foundations) and during operation (e.g.,
underwater noise generated by the wind turbines).
·
Evaluate the
significance and acceptability of such impacts during Project construction and
operation;
·
Recommend all
possible alternatives and practicable mitigation measures to avoid adverse
ecological impacts during Project construction and operation upon pelagic
species
·
Evaluate the
feasibility and effectiveness of any recommended mitigation measures, quantify
as far as practicable the residual impacts of mitigation measure implementation
and evaluate the acceptability of any residual impacts using the criteria in
Annex 8 of the TM; and
·
Review any
requirements for ecological monitoring.
6.3 Legislation, Standards & Guidelines
6.3.1.1
Reference has been made to the following local legislation governing
conservation of marine ecological resources:
·
Wild Animals Protection Ordinance (Cap. 170) provides for the protection of species listed in '
Schedule 2 ' of the Ordinance by prohibiting the disturbance, taking or removal
of such animals, their nests and eggs. This Ordinance excludes fish and marine
invertebrates, but does allow for the protection of all marine mammals found in
HKSAR waters.
·
Protection of Endangered Species of Animals and
Plants Ordinance (Cap. 586) controls the local
possession of any endangered species of animals and plants listed in its
schedules. These include both species of
marine mammal resident in the HKSAR.
·
Fisheries Protection Ordinance and Regulations
(Cap. 171) regulates fishing practices, aims to
prevent activities detrimental to the fishing industry and aims to protect
fishes and other marine biota in HKSAR waters.
6.3.1.2
Relevant Mainland regulations include the Wild Animals Protection Law that inter alia protects the habitats of all wild fauna, including the
creation of Class I /II protected species lists (Class I species being of
greater concern). Chinese white
dolphin and Finless porpoise are listed as Class I and Class II National Protected Species,
respectively.
6.3.1.3 Other relevant international regulations include:
·
Convention on International Trade in Endangered
Species (CITES) [of Wild Flora and Fauna] has
listed Chinese white dolphin and Finless porpoise as Appendix I species, i.e. most
endangered species which are prohibited from international trading.
·
The International Union for Conservation of
Nature and Natural Resources (IUCN) Red List has
listed Chinese white dolphin and Finless porpoise as data deficient species,
i.e. insufficient data on abundance and / or distribution.
·
Convention on the Conservation of Migratory
Species of Wild Animals (CMS) has listed Chinese
white dolphin and Finless porpoise as Appendix – II Species, i.e. migratory
species conserved through Agreements.
6.4.1.1 A review of available data and information was conducted. The most relevant updated sources of data / information for marine mammals includes inter alia:
·
AFCD, 2000.
Conservation Biology of the Finless porpoise (Neophocaena phocaenoides) in Hong
Kong Waters Final Report. Agriculture Fisheries and Conservation Department
(AFCD), HKSAR Government.
·
AFCD, 2005.
Monitoring of Finless Porpoise (Neophocaena phocaenoides) in Hong Kong Waters
(2003-05). Final Report. AFCD, HKSAR Government.
·
AFCD, 2006.
Monitoring of Hump-backed Dolphins (Sousa chinensis) in Hong Kong Waters Data
Collection and Final Report. AFCD, HKSAR Government.
·
AFCD, 2008,
Monitoring of marine mammals in
·
6.4.1.2 Key data sources on the fish species of the HKSAR and Eastern Waters included:
·
Binnie Consulting
Ltd., 1994. South of Ninepins Borrow
Area, Environmental Impact Assessment, Civil Engineering Department (CED),
Geotechnical Engineering Office.
·
Binnie Consulting
Ltd., 1995.
·
Binnie Consulting
Ltd., 1995. Marine Ecology of
6.4.2.1 As required by the EIA Study Brief, a 12-month boat-based marine mammal survey was conducted between June 2006 and July 2007. The survey adopted the survey route used for past studies in the Study Area, with reference to the methodology adopted AFCD, 2006. Figure 6.1 illustrates the survey route.
6.4.2.2 Searches and observations were conducted on the open upper deck of the survey vessel (a 15 metre coastal vessel) from the flying bridge area at an elevation of 4 - 5 metres above the water surface. A principal observer conducted the searches aided by suitable magnifying binoculars (e.g., 8 x 42) for scanning a search area in front of the vessel (between 270˚ and 90˚ in relation to the bow as 0˚). A secondary observer primarily conducted searches without the aid of binoculars and recorded data.
6.4.2.3 The data recorded during the course of each survey included time, distance and position of initial sighting (measured using a hand-held GPS), size and age composition of groups and behaviour, including response to the survey vessel.
6.4.2.4
All sighting data was only
validated when the sea state at the
6.4.2.5
The survey vessel travelled
along the route at a constant speed of
6.4.3 Independent Expert Appraisal
6.4.3.1 The consultancy services of marine mammal behaviour and ecology expert Dr. Bernd Würsig were engaged in starting April 2008 to conduct a peer review of marine mammal activity / sensitivity to the Project, and to advise on monitoring and management requirements of the proposed Project area. This Section of the EIA Report therefore incorporates the suggestions of Dr Würsig.
6.5 Ecological Baseline Profile
6.5.1 Marine Mammals: Literature Review
6.5.1.1
There has been much research carried out in Hong Kong on marine mammals
since the early
6.5.1.2
Almost all of the work carried out north and west of Lantau Island was
relative to Indo-Pacific humpback dolphins, Sousa
chinensis. Less research has been conducted in the Eastern Waters of Hong
Kong, and most of this work has concentrated on finless porpoises, Neophocaena phocaenoides. These two species of marine mammals are
resident in some of HKSAR waters all year.
6.5.1.3
Indo-Pacific hump-backed
dolphins are mostly
white or pinkish colour with shaped spots and flecks (Jefferson, 2000). Black
marks surround their eyes and their body shape is strong with large, broad
flippers and flukes. Their average length is approximately 2.5 metres, and
their beaks account for 6-10% of total length.
6.5.1.4
These dolphins, most frequently observed in waters off North Lantau,
usually travel in small schools of less than 10 individuals and are commonly
found associated with fishing vessels, such as pair trawlers, in the western
HKSAR waters. Common behaviour includes
travelling, foraging, feeding and socialising. Their mean dive time is about
40-60 seconds (Parsons, 1997).
6.5.1.5
Common prey species include croakers Johnius
spp., lionhead Collichthis lucida
and anchovies Thryssa spp. (AFCD,
2006). Studies of the stomach content of
carcasses suggest that this species does not consume many cephalopods or
crustaceans, but mostly feeds on demersal estuarine fish species (Barros et al., 2004).
6.5.1.6
Indo-Pacific hump-backed dolphins display a seasonal distribution, although their range appears to be largely restricted to
the estuarine waters of the Pearl River Delta.
There are few observation records in Eastern Waters of the HKSAR that have a dominant
oceanic influence (Parsons,
1997
6.5.1.7 Finless porpoises have no dorsal fin, rostrum nor beak. They are smaller than dolphins, growing to less than 2 metres in length. Adults are generally light grey in colour, while the juveniles are a darker grey.
6.5.1.8 The relatively cryptic nature of finless porpoises, with shallow and brief surfacing behaviour and very limited breaching or aerial behaviour, hinders the detection or study of these species (Jefferson, 2000). They are most commonly seen during feeding, travelling and milling.
6.5.1.9
This species feeds on mostly cephalopods of the families Loliginidae,
Octopodidae, and Sepiidae, and on demersal fish families including Apogonidae,
Carangidae, Clupeidae, Congridae, Engraulidae, Leiognathidae, Maemulidae,
Mugilidae, Nemipteridae, Sciaenidae, and some panaeid shrimps (Barros et al. 2002; Parsons 1997). Based on their prey species it has been
suggested that finless porpoises predominantly seek coastal and non-estuarine
species (AFCD, 2005).
6.5.1.10
Although the activity of finless porpoises extends to and overlaps with
that of Sousa chinensis around south
Lantau and Lamma Island, these two species have not been reported to be
interacting which may indicate a partitioning of habitats within HKSAR waters
(Jefferson and Braulik 1999
6.5.1.11 Figure 6.3 displays seasonal distribution data for finless porpoises in HKSAR waters. These data may be broadly summarised as follows:
·
Spring (March to May):
peak season with significant numbers in southern waters.
·
Summer (June to August):
western areas of south Lantau and Lamma vacated by finless porpoises as
dolphins move into these southeastern waters.
·
Autumn (September to November): abundance appears to reach a low point possibly due
to offshore movement of animals south into Mainland waters.
·
Winter (December to February): move into western waters of
6.5.1.12
As regards non-resident species
of marine mammals, there are HKSAR observation records for a total of 16 such
species (Jefferson & Hung, 2007). Table 6.1 summarises confirmed sightings of
ten non-resident species that have been observed in the general vicinity of the
Study Area in recent years.
Table 6.1 Confirmed
Non-Resident Cetacean Sighting Records
|
Common Name |
Scientific Name |
Conservation Status* |
Confirmed |
||
|
IUCN Red List |
CITES |
CMS |
|||
|
Bryde’s
whale |
Balaenoptera edeni |
Data Deficient |
App. I |
App. II |
Stranding confirmed near |
|
Long-beaked common dolphin |
Delphinus
capensis |
Low Risk Least Concern |
App. II |
App. II |
Carcass found offshore Po Toi Island in May 2004. |
|
Risso’s dolphin |
Grampus
griseus |
Data Deficient |
App. II |
App. II |
3-4 strandings reported near |
|
Pantrophical spotted dolphin |
Stenella
attenuata |
Low Risk Conservation Dependent |
App. II |
- |
Carcass discovered near Starling Inlet in |
|
Striped dolphin |
Stenella
coeruleoalba |
Low Risk Conservation Dependent |
App. II |
- |
A carcass was discovered at Shek O in 1996. |
|
Common bottlenose dolphin |
Tursiops aduncus |
Data Deficient |
App. II |
App. II |
Carcass discovered by Tung
Lung Chau in 2001. |
|
Indo-Pacific
bottlenose dolphin |
Tursiops truncatus |
Data Deficient |
App. II |
App. II |
Carcass found in waters
offshore |
|
False killer whale |
Pseudorca crassidens |
Low Risk Least Concern |
App. II |
- |
A carcass was reported on |
|
Rough-toothed dolphin |
Steno bredanensis |
Data Deficient |
App. II |
- |
A carcass was found near
Ching Chau in Sai Kung in May 2003. |
|
Sperm whale |
Physeter macrocephalus |
Vulnerable |
App. I |
App. I |
Stranding record in July
2003 at Tai Wan in Sai Kung. |
6.5.1.13 Given the prevalence of more visible marine mammal activity in the western HKSAR, relatively less effort has been placed into surveys of Eastern Waters. The most recent 2-year survey programme for finless porpoises was to investigate distribution and behaviour in southern waters, but also including waters around Po Toi, Ninepins and Sai Kung. Figure 6.4 presents the vessel transects adopted for these surveys.
6.5.1.14 Figure 6.5 presents the location of sightings recorded between 1996 and 2005. It is immediately evident that there is variation in the spatial distribution of sightings across surveyed waters.
6.5.1.15
An average biennial encounter
rate of 2.9 per
6.5.1.16 It is noted that these latest encounter rate data are somewhat higher than past data collected in Eastern Waters over the past decade. Figure 6.6 summarises the summer encounter rate per 100km in each of the three survey zones in Eastern Waters: Sai Kung, Ninepins and Po Toi. It is apparent that when considering a longer-term data set that there is considerable variation in encounter rate both within and between these zones. For example, within the Ninepin survey zone a summer biennial encounter rate of 9.6 sightings / 100 km was recorded in the 1996/97 survey, while only one sighting was recorded in the subsequent 1998/99 survey (i.e., encounter rates of approximately 0.2 sightings / 100 km) and with no sightings in the 2000/01 survey. Also, while the 2005 survey recorded a summer encounter rate of 7.6 in Po Toi, the latest AFCD study in 2008 recorded a summer encounter rate of only 1.9 there (AFCD, 2008). The 2008 survey did not conduct surveys in Sai Kung and the Ninepins.
6.5.1.17
Jefferson (AFCD, 2000)
cautioned about drawing linkages between encounter rates and actual abundances. He stated
that “any trends observed in the estimates, even if real, may simply reflect
local movements of animals and not necessarily changes in overall abundance of
the population (e.g. the redistribution factor)”. Jefferson (AFCD, 2000) pointed out that
variation in the encounter rate is reasonable as finless porpoises can travel freely between local and regional waters,
and more importantly, the survey area does not contain any closed finless
porpoise population.
6.5.1.18 Environmental conditions likely play an important role in the distribution of finless porpoises. Parsons (1998b) set forth a correlation between physical environment and the relative abundance of the species in local waters. Finless porpoises appear to respond positively with cooler water of higher salinity, which may explain the overall higher encounter rates during winter and spring (AFCD, 2007). Other elements that may affect finless porpoise distribution patterns include reproductive cycles, hydrography, diurnal patterns and tidal state (Parsons, 1998b).
6.5.1.19 In conclusion, although finless porpoises are present in Eastern Waters year-round, analyses show sporadic and low occurrence in all seasons and large fluctuations in different areas / zones.
6.5.2 Marine Mammals: 2006/07 Field Survey
6.5.2.1
Updated baseline data on marine
mammals utilising the Study Area was collected specifically for the purposes of
this EIA Study through a series of boat-based transect surveys. Surveys were undertaken on 25 days during the
year, equivalent to one event approximately every 15 days. The survey frequency was dictated by offshore
weather conditions, and despite reliance on general weather forecasts for the
offshore area obtained from the
6.5.2.2
Overall the average length of
each transect was ~
6.5.2.3
The survey area covered
Ninepins and part of the Sai Kung transect routes adopted by previous surveys
commissioned by AFCD (2000 & 2005) (Figure 6.1 and Figure 6.4 refer). The survey was focussed on offshore Eastern
Waters, the proposed wind farm footprint area - some
6.5.2.4
The surveys resulted in only
five individual resident finless porpoises being observed ‘on effort’ over two
days, equal to an average encounter rate of about 0.2 sightings per
While the encounter rate of 0.2 finless
porpoise sightings per 100km is lower than the AFCD data collected between 2003
to 2005, the literature review indicates that the encounter rate of finless
porpoise in Eastern waters could be highly variable and sporadic. The encounter rate during the latest 2008/09
AFCD survey (AFCD pers. comm.) in
6.5.2.5 The variable but generally low encounter rate does not suggest that finless porpoises are absent from Eastern Waters. For example, anecdotal evidence obtained through discussions with fishermen for this EIA study would strongly suggest that the species is present year-round in waters around the Ninepins (defined in the broadest sense), although not in any significant numbers. There are also strong indications from the survey completed for this EIA study and from expert opinion (for example, Würsig, pers. comm.) that the visual observation method used in isolation in a low encounter rate area may be of limited effectiveness; a fact that cannot be overlooked when considering options for future monitoring and management of the marine environment for the benefit marine resources [sub-section 6.10.1 refers].
6.5.2.6 A total of 15 False killer whales Pseudorca crassidens – an occasional migrant – were also observed ‘on effort’ in a single day in open waters. A pod of 12 specimens was also incidentally observed at close quarters a few days before during sediment sampling at the northeast of the proposed Wind Farm area, enabling video and photographic records to be taken (Figure 6.7). It is likely that these observations were of the same pod.
6.5.2.7 Figure 6.8 presents the locations of all observations made, while Table 6.2 presents a summary of the sightings.
Table 6.2 Summary
of Marine Mammal Observations
|
Obs. Ref. |
Date (2007) |
Species |
Count |
Coordinates |
Sighting
Angle^ |
Observer Distance
(m) |
Beaufort Scale |
|
|
Northing |
Easting |
|||||||
|
1 |
14 Feb |
Finless Porpoise |
4 |
809,757 |
847,094 |
090˚ |
200 |
2 |
|
2 |
10 Mar |
Finless Porpoise |
1 |
815,696 |
860,249 |
N.A.* |
<50 |
4 |
|
3 |
13 Apr |
Finless Porpoise |
1 |
808,897 |
808,897 |
270˚ |
8 |
2 |
|
4 |
16 Apr |
Finless Porpoise |
1 |
814,274 |
852,385 |
N.A.* |
100 |
1 |
|
5 |
16 Apr |
Finless Porpoise |
3 |
812,491 |
860,654 |
N.A.* |
100 |
1 |
|
6 |
4 May |
False Killer whale |
12 |
817,876 |
861,805 |
0 - 360˚* |
4 - 200 |
1 |
|
7 |
7 May |
False Killer whale |
15 |
817,165 |
857,679 |
270˚ - 90˚ |
10 |
2 |
Notes: ^ Sighting angle from
vessel (bow = 0 degrees)
* Incidental observations
6.5.3.1
There has been a general dramatic
decline in fish abundance in HKSAR waters from the middle of the last
century. In the 1950s the catch per unit
effort for trawlers in local waters was about 90
6.5.3.2 This general decline continued through the 1990s and early 2000s, by which time local catches of fishes and invertebrates were dominated by juvenile fishes and small and fast growing species such as pony fish (Leung, 2000; WWF, 2005). The similarity in catch over these years suggested that the marine ecosystem was stable at a depressed level (Sumaila et al, 2007).
6.5.3.3
Given the
absence of any major project development in Eastern Waters in the intervening
period, and the general decline in fisheries productivity through the 1990s to
the present day, the results of two ichthyoplankton
surveys conducted in the mid-1990s
are still valid.
6.5.3.4
Figure 6.9 presents the coverage
and nature of these surveys, with the proposed wind farm in ‘Zone
6.5.3.5
The ichthyoplankton survey’s
result are consistent with the findings of the Port Surveys 1996/1997 and
onwards that Eastern Waters is not a major spawning ground in
6.5.3.6
A series of trawl and gillnet
surveys were undertaken during the early and mid 1990s in waters off
6.5.3.7
The trawl survey recorded a
total of 41 species of fish and 67 species of invertebrate. The dominant fish catch was the rifle
cardinal (62% of catch) which is known as a highly resilient species (Binnie
Consulting Ltd, 1994). Conversely,
species with a relatively high value / low resilience only made up a small
fraction of the catch. The average fish
biomass was <
6.5.3.8
The species composition caught
using gillnetting was generally different from that using trawling, with
greyfin croaker, Belenger’s croaker and lizard fish making up 40% of total
catch in the survey area. Table 6.3 presents a record of reef associated fish
species caught in waters around the
Table 6.3 Reef-Associated Fish Species around the Ninepins
|
Species
Name |
Common
Name |
Habitat Description |
Resilience
to Fishing Pressure |
|
Apogon kiensis |
Rifle cardinal |
reef-associated; brackish; marine; depth
range 0 – |
High (population doubling time = 15 months) |
|
Apogon ellioti |
Flag-in cardinal-fish |
reef-associated; marine; depth range 18 – |
High (population doubling time = < 15
months) |
|
Engyprosopon
grandisquama |
Large-scale flounder |
Reef-associated; marine; depth range 7 – |
High (population doubling time = < 15
months) |
|
Chaetodon modestus |
Brownbanded butterfly fish |
reef-associated; oceanodromous; marine;
depth range 40 – |
High (population doubling time = < 15
months) |
|
Sillago sihama |
Silver sillago |
reef-associated; amphidromous; brackish;
marine; depth range 0 – |
High (population doubling time = < 15
months) |
|
Aesopia cornuta |
Horned sole |
reef-associated; marine; depth range 8 – |
Medium, population doubling time = 1.4 – 4.4
years |
Source: Binnie Consulting Limited (1994)
6.5.4.1
Occasional
sightings of sharks are generally made in local waters during the months of May
through September. Historic records indicated that various sharks
used to be somewhat common in local waters, although there have been no recent
records of species such as the Spottail shark and the Whitetail shark since the
6.5.4.2
No formal
field research has been conducted in local marine waters, although past
desk-based research indicates that several species have been observed within
HKSAR since the
Table 6.4 Shark, Ray & Skates in HKSAR Waters
|
Family |
Species Name |
Common Name |
Conservation Status |
|
Orectolobiformes (Carpet sharks) |
Chiloscyllium
plagiosum |
Whitespotted bambooshark |
IUCN –Near Threatened |
|
Carcharhiniformes (Ground sharks) |
Carcharhinus
macloti |
Hardnose shark |
IUCN – Near Threatened |
|
Rhizoprionodon
acutus |
Milk shark |
IUCN – Least Concern |
|
|
Scoliodon
laticaudus |
Spadenose shark |
IUCN – Lower Risk Near Threatened |
|
|
Narcine
indica |
Large spotted numbfish |
Not Listed |
|
|
Rajiformes (True rays & skates) |
Narke
japonica |
Japanese sleeper ray |
Not Listed |
|
Aetomylaeus
niehofii |
Banded eagle ray |
Not Listed |
|
|
Platyrhina
sinensis |
Fanray |
Not Listed |
|
|
Anacanthobatis
melanosoma |
Blackbodied leg skate |
Not Listed |
|
|
Raja
hollandi |
Yellow spotted skate |
Not Listed |
|
|
Raja
kwangtungensis |
|
Not Listed |
|
|
Dasyatis
akajei |
Red stingray |
IUCN – Near Threatened |
|
|
Dasyatis
bennetti |
Bennett's stingray |
Not Listed |
|
|
Dasyatis
kuhlii |
Bluespotted stingray |
Not Listed |
|
|
Dasyatis
zugei |
Pale-edged stingray |
IUCN – Near Threatened |
|
|
Himantura
gerrardi |
Sharpnose stingray |
Not Listed |
|
|
Gymnura
bimaculata |
Twin-spot butterfly ray |
Not Listed |
|
|
Aetobatus
flagellum |
Longheaded eagle ray |
Endangered |
|
|
Aetobatus milvus |
Eagle ray |
Not Listed |
Source: Ni and Kwok (1999).
6.5.4.4 As sharks, rays and skates appear to be only occasional visitors to HKSAR waters and in small numbers, this group of animals is unlikely to be exposed to impacts from Project development and is not considered further in this assessment.
6.5.5.1
Five species of sea turtle have
been recorded in HKSAR waters: the Loggerhead, Green Turtle, Leatherback,
Hawksbill and Olive Ridley. Only the green turtle is
known to breed in
6.5.5.2
A female green turtle was observed on the sandy beach at Tai Long Wan in
September 2006, and this observation led to 65 eggs collected being
artificially incubated, successfully hatched and all juveniles released at Tai
Long Wan in July 2007. The remaining 18 eggs were kept on site for natural
incubation. The previous documented green turtle nesting event at Tai Long Wan
was in the 1970s.
6.5.5.3
AFCD’s Green Turtle satellite tracking programme has followed one female
egg-laying turtles returning from Sham Wan beach at south
6.5.5.4
Data from the programme has also tracked adult Green Turtle movements
through Eastern Waters, with tracks indicating movement through waters off Tai
Long Wan, around
6.5.5.5
Commonly documented threats to sea turtles in the marine environment
include fishing activity and floating debris.
Fishing activity using long-lines and gill-nets can lead to entanglement
and drowning, or may lead to flipper injury due to constriction by fishing lines
or trawling nets, while marine debris such as plastic bags may converge with
natural food prey such as jellyfish in oceanographic drift zones, leading to
ingestion and suffocation (NOAA, 2008). The issue of floating debris is a
particular problem for sea turtles that spend a significant portion of their
life cycle in the pelagic environment (e.g., juvenile green turtles).
6.5.5.6
During the Construction Phase it is anticipated that as major sections
of the windfarm are installed the windfarm footprint will be progressively
designated as a controlled waterspace through the deployment of byelaws or
similar legal instruments that will be sought for the windfarm site.
Waterbourne access would be restricted to vessels that have received approval
from the authority specified in the legal instruments.
6.5.5.7
Given the low volume and low speed of vessel traffic present during
construction operations due to the designation a controlled waterspace, any sea
turtles present in the area should be able to easily avoid the slow moving
construction vessels. The controlled waterspace mentioned above will also be in
effect during the Operations Phase which will ensure that vessel traffic will
not significantly change from present levels.
6.5.5.8
As jetting of the cable route will only cause temporary, localized
disturbances at the specific location along the cable route being jetted at any
particular time, the most likely behavior for any turtles present will be to
avoid the immediate area around the jetting works.
6.5.5.9
There is a regional tradition of hunting sea turtles, with turtle scales, skins and shells being ingredients in traditional Chinese
medicine. For example, in March 2000
over 450 kilograms of sea turtle skin and shells
found hidden inside containers from Indonesia and the Philippines en route to
the Mainland. Based on the quantities of
skins and shells seized, it was estimated that 600 sea turtles had been
illegally poached (C&E, 2000).
6.5.5.10
Locally, there has been a tradition of sea turtle egg collection, while other terrestrial threats to the nesting Green
Turtles at the Sham Wan,
6.5.5.11 The proposed Project will not contribute to any of the existing marine or terrestrial threats referred above, although the issue of turbine lighting that may potentially lead to disorientation of adult and hatchling Green Turtles is discussed under the operational phase impact assessment in sub-section 6.7.5. The potential noise impacts of the low level of construction vessel traffic that will be present during the Construction Phase is dealt with in sub-section 6.6.3.
6.6 Construction Phase Impact Assessment
6.6.1.1 Given the construction method, the primary potential ecological impact on pelagic species is indirect water quality induced impacts associated with marine construction activities. Construction noise shall be a relatively minor issue as no marine piling shall be undertaken for the project.
6.6.2 Water quality induced impacts
6.6.2.1 Numerical modeling has been conducted to predict the increase in levels of suspended sediment at representative locations within the Study Area, including at coral reefs inhabited by reef fish and open waters where marine mammals have been observed. Details of the methodology for the assessment of water quality induced impacts are presented in sub-section 4.6.
6.6.2.2 Movements of reef fish at the underwater pinnacles of Victor Rock and One Foot Rock may be restricted due to the isolation of these features, with the result that the impact of elevated levels of suspended sediment on reef fish, and pelagics that feed on them, at these receivers may be greatest. In contrast, the larger contiguous area of reef habitat at the rocky islands would enable reef fish to avoid any sediment plume by swimming into unaffected waters around the coast.
6.6.2.3 Numerical water quality modelling, presented in sub-section 4.7.3, predicts no increases in the level of suspended solids at sensitive receivers. All increases, except at CC26, CC27 and CC11, were significantly below WQO criteria. The exceedances at CC26, CC27 and CC11, resulted in the adoption of mitigation measures such as silt curtains and restrictions on dredging rate presented in sub-section 4.9.
6.6.2.4 Table 6.5 presents the predicted results for the mitigated scenarios which confirm full compliance with WQO criteria at these sites. Hence, no adverse impacts are anticipated for coral, fish and any associated pelagic activity at these WSR, regardless of whether it is an underwater pinnacle or continuous reef habitat.
Table 6.5 Predicted SS Increases (in mg/L) at representative Coral Community Water Sensitive Receivers: Mitigated Scenario
|
ID |
Coral Community |
Allowable Elevation |
Mitigated peak concentration above baseline* / Scenario |
|||||
|
Dry |
Wet |
1 |
2 |
3 |
4 |
5 |
||
|
CC26 |
|
2.24 |
2.03 |
0.91 |
0.91 |
0 |
0 |
0 |
|
CC27 |
|
2.24 |
2.03 |
0.94 |
0 |
0 |
0 |
0 |
|
CC11 |
Fat Tong Chau West |
2.24 |
2.03 |
0.02 |
0 |
0.80 |
0.77 |
0.77 |
6.6.2.5 Marine mammals and other truly pelagic species that routinely travel long distances thoughout HKSAR waters would be able to swim into open waters to avoid sediment impact. Also, as marine mammals surface to breathe, their respiratory surfaces are not affected by suspended sediment in the water.
6.6.2.6 The unlikelihood of any adverse impacts to marine mammals is further supported by the water quality modelling results. Suspended sediment increases were only predicted at two sites, presented in Table 6.6, where increases were very small and remained significantly below WQO criteria without the need for any mitigation.
Table 6.6 Predicted SS Increases (in mg/L) at representative Marine Mammal Water Sensitive Receivers: Unmitigated Scenario
|
ID |
Name |
Allowable Elevation |
Unmitigated peak concentration above baseline / Scenario |
|||||
|
Dry |
Wet |
1 |
2 |
3 |
4 |
5 |
||
|
MM8 |
Sighting Point of Marine Mammal |
2.24 |
1.87 |
0 |
0.32 |
0 |
0.32 |
0 |
|
MM11 |
Sighting Point of Marine Mammal |
2.24 |
1.87 |
0 |
0.09 |
0 |
0.09 |
0 |
6.6.2.7 Water quality modelling predicts that the levels of suspended solids at all representative pelagic sensitive receivers shall be significantly below the WQO impact evaluation criteria. Accordingly, no adverse impacts upon fish, marine mammals or other pelagic species are anticipated.
6.6.3 Underwater Noise
6.6.3.1
A
comprehensive review and assessment of underwater noise effects on marine
mammals and fish has been conducted by Thomsen et al (2006) based on wind farm developments in the
6.6.3.2
Studies have shown that
European harbour porpoise Phocoena phocoena
communicate with a range of sounds, and can hear in the range of 16 – 140 kHz
(Kastelein et al., 2002). The sounds emitted by this species – in the
same taxonomic Family as the finless porpoises resident in HKSAR waters – have
been categorised as follows based on Verboom and Kastelein (1995):
·
Low frequency
sounds at 1.4 – 2.5 kHz for communication
·
Sonar-clicks
(echolocation) at 110 – 140 kHz
·
Low-energy sounds
at 30 – 60 kHz
·
Broadband signals
at 13 – 100 kHz
6.6.3.3 Sonar clicks have been found to be the main sound emitted by the harbour porpoise (ibid.). Similarly, studies of the finless porpoise suggest that it produces similar sonar clicks at a peak frequency of 142 kHz (Goold & Jefferson, 2002).
6.6.3.4 As regards potential construction phase impacts, marine dredging / jetting works and large marine vessels typically emit sound in the range of 0.02 to 1 kHz (Goold & Jefferson, 2002; Popper et al, 2003). Medium sized offshore support and supply vessels typically generate noise at frequencies between 0.02 to 10 kHz (Richardson et al. 1995), with marine vessel noise measured near the Urmston Road in western HKSAR waters at 2.5 kHz (Würsig and Greene, 2002). These underwater noises are thus generally below the hearing range of finless porpoises, and certainly below the documented peak hearing range of ~140 kHz for porpoises.
6.6.3.5 Construction noise levels are also generally below the 8 - 90 kHz hearing range of the Indo Pacific Hump-backed dolphin, Sousa chinensis reported by Richardson et al (1995), although this species is uncommon outside its preferred estuarine habitat and thus a very uncommon sighting in the Study Area. Construction noise levels are also below the most sensitive hearing range of false killer whales, Pseudorca crassidens reported by Thomas et al (1988) was between 16 -64 kHz.
6.6.3.6 It is clear from past AFCD visual and acoustic studies, and the present BMT visual study, that finless porpoises and other cetaceans do not use the east Hong Kong proposed Wind Farm area to a high extent (for example, Jefferson et al., 2002; AFCD, 2005, 2007). The foundation structures of the proposed Wind Farm are to be installed using the relatively non-noisy suction can foundation system. While there may be some avoidance of the immediate area (within about 200 to 500 m) during construction (based on data from various reports on European harbour porpoises), no adverse impacts on marine mammals are anticipated during marine construction activities.
6.6.3.7
A 2006
study by the Woods Hole Oceanographic Institution on the hearing ranges of sea
turtles found that juvenile green turtles have the broadest hearing range
(100-800 Hz; best sensitivity 600-700 Hz). This is within the anticipated range
of noise generated by construction activity. However given the minimal number
of sea turtle sightings that have been recorded in the area, the low number and
low speed of construction vessels, and the fact that construction activities
are taking place in the open ocean, it is expected that temporary avoidance
behaviour will be the norm for sea turtles during the construction phase and
there will be no significant adverse noise impacts.
6.6.3.8 The hearing ranges of fishes has been studied less, although a hearing range for fish of 30 Hz to 1 kHz is generally agreed, recognizing that some species can hear sound below or above this range (Popper et al, 2004). Accordingly, noise from construction activities may affect fishes in the Study Area.
6.6.3.9
Construction activities will
lead to an increase in the number of marine vessels at the proposed wind farm from
the present (low) baseline average of 20 vessels / day, and thus marine vessel
activity shall be the primary noise source for fishes. Construction marine traffic will include the
heavy lift vessel for turbine installation, a dedicated cable laying vessel and
a variety of tugs and work boats to support operations. Work at the proposed wind farm will occur in
concentrated periods and during the busiest days up to 15 vessels may be
operating (BMT, 2007). Although this would effectively create a short term
doubling of vessels, the marine traffic density would be less than 0.2% that of
6.6.3.10
The seabed of the proposed wind
farm is exposed and offers no habitat for fin fishes, while no turbine
installation activities shall be in proximity to reef fish habitat at the
6.7 Operational Phase Impact Assessment
6.7.1.1 Potential sources of operational phase impacts are associated with noise from turbine operation, noise and collision risk upon marine mammals associated with maintenance vessel activity, and electro-magnetic field effects from transmission and array cabling. Section 4.8 identified that normal project operation will cause no significant changes in water quality, which indicates that there will be no indirect ecological impacts on finless porpoises, false killer whales, green turtles and other pelagic species during the operational phase.
6.7.1.2 The positive ecological impact associated with the presence of a cumulative surface area of over 100,000m2 of foundation structure has been mentioned in sub-section 5.8. The general benefits to fisheries are further elaborated in sub-section 8.7.
6.7.2 Underwater Noise
6.7.2.1
With reference to Thomsen et al (2006), underwater noise data from
a 1.5MW turbine operating in winds of
6.7.2.2
Using the harbour porpoise as a
proxy for the finless porpoise (sub-section
6.7.2.3 Figure 6.12 displays data from boat-based surveys at Horns Rev Offshore Wind Farm presenting a drop in porpoise distribution during piling, but recovery to baseline levels during operation. Thus, while it appears that there may potentially be a behavioural response from finless porpoises to turbine noise, significant adverse impacts are not anticipated.
6.7.2.4 As referred previously, we can assume a general hearing range for fish of 30 Hz to 1 kHz (Popper et al, 2004), although it has also been suggested that fish display a weak response to sounds in the range 50 Hz to 1 kHz and that in this range the influence of turbine noise is likely to be minor (Knudsen et al, 1994; Westerberg, 1995).
6.7.2.5 Low frequency noise below 50 Hz is considered to be of most importance for fish, and this has been suggested as the reason why fish display a consistent behavioural response and even an attraction to low frequency disturbance (Knudsen et al, 1994; Westerberg, 1995). Wahlberg and Westerberg (2005) estimate the range within which fish may be scared away from a turbine to be less than 5 metres. Accordingly, significant adverse underwater noise impacts on fish are not anticipated.
6.7.2.6 Studies of medium sized offshore support and supply vessels indicate noise is mainly generated at frequencies between 20 Hz and 10 kHz (Richardson et al. 1995) and thus outside the key frequencies of concern.
6.7.3 Marine Vessel Collision Risk
6.7.3.1 The stand-alone Marine Navigation and Safety Risk Assessment (BMT, 2007) has concluded that access restriction is required in order to manage anticipated human behavioural responses such as scaling of turbine towers, trawling immediately adjacent to foundations and entry of un-seaworthy sight-seeing vessels within the wind farm.
6.7.3.3 The marine control measures, the low baseline traffic volume of the wind farm site, and the low density of marine mammal and sea turtle activity in Eastern Waters will result in a negligible level of collision risk. Especially when compared with the marine traffic volume of over 2,000 vessel movements per day through the core habitat of the Indo Pacific hump-backed dolphin Sousa chinensis on a daily basis.
6.7.4 Electro-magnetic Field
6.7.4.1
Most marine species can detect electromagnetic fields, although some
species are considered to be potentially more susceptible than others. Concerns
regarding effects on prey detection of rays and sharks, for example, have been
raised in the past although current knowledge is limited in terms of
species-specific data. The industry
standard 132kV cables to be adopted by the proposed project have been shown to
produce a magnetic field of 1.6mT and an induced electric field
of approximately 91mV/m. This magnetic field is small
in comparison the Earth’s natural geomagnetic field of 50mT, and is estimated to fall to
background levels at a distance of ~
6.7.4.2
As two parallel cables are to be installed for the wind farm operation
there shall be a cumulative effect, although the strength of the field is
limited when cables are buried as sediment dissipates the induced electric
field much more rapidly than sea water (ibid.). Accordingly, the effects of the field on
fishes and other marine life are anticipated to be negligible.
6.7.5.1
Existing potential marine threats to sea turtles from marine traffic
(6.7.3 refers) and floating debris will not increase during Project operation
as the wind farm area would be under strict management control.
6.7.5.2
As regards terrestrial threats associated with project operation, artificial lighting could deter an
adult female Green Turtle from emerging from the sea to nest, although there
shall be no lighting within some 10 km of the nesting beach at Tai Long Wan while
well-lit container vessels use the approach to Yantian Port 24-hours a
day. In this context, and given that
Green Turtles have been tracked passing through HKSAR Eastern Waters (e.g.,
AFCD, 2003 and AFCD unpublished data) under existing baseline conditions,
artificial lighting from the offshore turbines is not anticipated to result in
any adverse impact on adult female Green Turtles that may come into the area.
6.7.5.3
For Green Turtle hatchlings, lighting behind a nesting beach may
disorient emerging hatchlings away from the sea as hatchlings tend to move
towards the brightest direction (NOAA, 2008).
In the case of the proposed Project, this direction would still be
towards the broad horizon of the open sea, and no adverse impact would arise.
6.8 Mitigation Measures & Best Practice
6.8.1.1
Referring to Thomsen et al (2006), if less noisy construction methods to
percussive piling exist, these should preferentially be used. For the proposed
project, considerable effort has been taken to investigate the feasibility of
the suction caisson foundation option, with this construction method selected
as preferred to avoid adverse impacts.
In addition, as a precautionary measure, a 250
metre exclusion zone shall be implemented around the works barge during
installation of foundations and turbine sub-structures.
6.8.1.2
Controls on dredging and jetting activities as referred in sub-section
4.8.1 shall ensure that impacts on reef fish at minor coral communities in
6.9 Residual Impact Assessment
6.9.1.1 Due to the use of low impact suction caissons and the implementation of the marine mammal exclusion zone, no significant adverse impacts are anticipated during the construction phase. Previous sections have also identified that that the already negligible operational phase impacts will be further reduced by the designation of the wind farm area as a controlled water space. As a result, no specific mitigation is required as no adverse impacts on the pelagic ecosystem are anticipated. Accordingly, there shall be no residual impacts.
6.10 Environmental Monitoring & Audit Requirements
6.10.1 Monitoring of Marine Mammals
6.10.1.1 It has been well-documented for all but Dall’s porpoises (Phocoenoides dalli), that porpoises of the family phocoenidae (as opposed to most dolphins, delphinidae) tend to be cryptic while they surface to breathe, and are therefore difficult to see. This is exacerbated in the finless porpoise, as it is small and even more difficult to see than other species due to the lack of a dorsal fin, as well as a muted gray coloration that often makes the porpoise blend in with a slightly choppy water surface (Jefferson and Hung, 2004).
6.10.1.2 Furthermore, following literature review and the 2006/07 field survey event for this Project, it is evident that there are factors that amplify limited data in areas with an already low encounter rate. These include:
·
Changes in local distribution pattern: fluctuating porpoise utilization rate has been
recorded across eastern waters (Figure 6.6 refers).
·
The survey methodology: Studies
at Nysted Offshore Wind Farm in Denmark for example concluded that as porpoises
were mostly active at night-time, there were fundamental limitations in visual
only (i.e., day-time) surveys.
·
Weather conditions: the
vessel-based observation method is highly weather dependent and can be compromised
greatly by, for example, low sunlight intensity (Evans, 2008). Locally, Jefferson (AFCD, 2000) concluded
that the overall abundance, which is a function of sighting rate and
probability density function, could drop by as much as 42% when survey observations
were conducted in unfavourable environmental condition.
6.10.1.3 For such reasons, cetacean studies for international offshore wind farm developments, such as the monitoring conducted at Nysted Offshore Wind Farm, have modified the approach by deploying acoustic devices which are less weather-dependent and can allow for continuous monitoring. Such devices, or passive acoustic monitors (PAMs), are invaluable for detecting the high frequency clicks of porpoises that are easily-distinguished from sounds of other marine animals.
6.10.1.4 Most monitoring work of this type has been carried out on European harbour porpoises, Phocoena phocoena (Villadsgaard et al., 2007; Evans, 2008), although the technique has also been experimentally demonstrated locally for finless porpoises using towed recording devices jointly engaged during line transects. (Jefferson et al. 2002: Goold and Jefferson, 2002).
6.10.1.5
One type of PAM is the T-POD
(for, “
6.10.1.6 Given the above, we do not suggest further stand-alone use of the visual observation method to obtain more information on porpoise occurrence patterns in the general area. We have also explored the possibility of using visual surveys in conjunction with towed acoustic sensing devices (T-PODs) as were used by Jefferson et al. (2002) for detecting finless porpoises. While this double-system of evaluation was useful for corroboration of visual sightings, it is apparent that porpoises are at times shutting off their active acoustics due to the presence of the line-transect research vessel, and we have received expert advice (Nick Tregenza, Chelonia Ltd.) that as a result, it is unlikely that towed systems enhance visual surveys for finless porpoises, at least with present resolution and capabilities.
6.10.1.7 Based upon the above, we recommend the use of C-PODs to monitor the activity of finless porpoises both day and night and in all weather conditions due to their greater reliability relative to sensing porpoises as well as other marine mammals. Further details of the proposed monitoring programme shall be provided in the Project’s stand-alone Marine Environment Monitoring Plan (MEMP) to be developed in parallel with the engineering design, although the two core elements shall involve:
·
Joint visual / C-POD Calibration survey: As bottom-mounted acoustic monitoring devices have not
previously been used for detecting finless porpoises, it is important that
these be calibrated relative to visual surveys.
It is thus proposed that a line transect survey be conducted in
conjunction with placement of C-PODs using standard approved line transect
methodology (as per AFCD, 2005, etc.) for calibration purposes. Given the low level of sightings (and, hence
potentially, acoustic contacts), the line transects and C-PODs should be
engaged in for sufficient time for statistical robustness relative to inter-calibration.
One option for this
work, to be discussed and agreed with AFCD prior to commencement, is to conduct
the joint acoustic / visual survey in HKSAR western
waters where finless porpoise activity is relatively high (compared with
offshore eastern waters), and hence with greater potential for good quality
calibration data. Under this scenario,
for example, deployment of 2-3 C-PODs combined with a 3-month visual survey
would likely yield good quality data for C-POD calibration. Ultimately the number of C-PODs to be
deployed and the necessary duration of visual transect survey for calibration
would depend on exactly where this part of the survey programme was to be
conducted.
·
Placement of C-PODs:
After inter-calibration of acoustic and visual data to support generation of an
accurate estimate of finless porpoises by the C-PODs, the second aspect of the
programme shall involve placement of these devices within and just outside the
wind farm area (for example, Teilmann et al., 2006). As Porpoise clicks are substantially above
100 kHz in frequency, not very loud (Goold and Jefferson, 2002) the detection
distance is likely to be on the order of low
The C-PODs deployed
will need to be serviced every three to four months to download accumulated
data and replace batteries. It is proposed that the C-PODs be installed after
installation of the turbines when security from trawling damage / loss can be
afforded, and for a sufficient period of time to obtain a robust record of
marine mammal usage of the area, especially due to the great inter-seasonal and
inter-year differences already known for finless porpoises.
6.10.1.8
The MEMP shall detail the
integrated monitoring requirements associated with pelagic ecology, benthic
ecology and fisheries resources within the Project area, and development and
implementation of the MEMP shall form a condition of the Environmental Permit.
6.10.2 Water Quality Monitoring
6.10.2.1
Focussed water quality
monitoring shall be conducted at
6.11
Conclusions
& Recommendations
6.11.1.1 A comparison of marine mammal distribution between HKSAR waters and Eastern Waters, it is evident that the waters of the proposed wind farm are not frequented by Indo-Pacific hump-backed dolphins and are only lightly utilized by finless porpoises – with this species preferring more sheltered coastal waters around the Ninepins and Po Toi islands. Given this low usage of the Study Area and the preferred construction method, no adverse long-term impacts are anticipated during construction and no mitigation measures are proposed. Nevertheless, monitoring of marine mammals over a suitable period of time is recommended in order to be able to detect overall changes in use of the area.
6.11.1.2
Quantitative assessment
predicts either no or only a marginal increase in suspended sediment above
baseline levels at most locations.
Although the worst-case assessment scenario of concurrent marine
dredging and jetting at
6.11.1.3 A review of potential noise impacts has been completed, and this does not suggest any adverse impacts from marine vessel activity during Project construction or operation, or from underwater turbine noise. Adverse impacts from the electromagnetic field are not anticipated.
6.11.1.4 The Project offers the opportunity for artificial reef development, with the presence of the foundations possibly attracting fish. Over time the establishment of epifauna on foundation structures is expected to support a more diverse reef habitat. Combined with restrictions on trawling and other marine traffic activity, the Project has the potential to generate a net positive impact.
6.12.1.1
AFCD (2000).
Conservation Biology of the Finless porpoise
(Neophocaena phocaenoides) in Hong Kong Waters Final Report. Agriculture,
Fisheries and Conservation Department, HKSAR Government.
AFCD (2002). AFCD tracks Green
Turtle by Satellite. Press Release dated Saturday, 9 November 2002.
Agriculture, Fisheries and Conservation Department, HKSAR Government.
6.12.1.2
AFCD (2005).
Monitoring of Finless Porpoise (Neophocaena
phocaenoides) in Hong Kong Waters (2003-05). Final Report. Agriculture, Fisheries and Conservation
Department, HKSAR Government.
6.12.1.3
AFCD
(2006a). Monitoring of Hump-backed Dolphins (Sousa
chinensis) in Hong Kong Waters Data Collection and Final Report. Agriculture,
Fisheries and Conservation Department, HKSAR Government.
6.12.1.4 AFCD (2006b). Comments from AFCD officer. Unpublished, 2006.
6.12.1.5
AFCD (
6.12.1.6
AFCD
(2007b). Seasonal distribution of Finless Porpoise: http://www.afcd.gov.hk/english/conservation/con_mar/con_mar_fin/con_mar_fin_fin/con_mar_fin_fin_dis_is.html
6.12.1.7
Barros,
N.B.,
6.12.1.8
Barros,
N.B.,
6.12.1.9 Binnie Consulting Ltd. (1994). South of Ninepins Borrow Area, Environmental Impact Assessment, Civil Engineering Department, Geotechnical Engineering Office.
6.12.1.10
Binnie
Consulting Ltd. (1995a).
6.12.1.11
Binnie
Consulting Ltd. (1995b). Marine Ecology of
6.12.1.12
BMT (2007).
6.12.1.13
Chan, K.F., Chan, J.K., Lo, L.T. and Balzas, G.H. (2003). Satellite Tracking of the Post-nesting Migration of a Green Turtle (Chelonia
mydas) from
6.12.1.14
Cheung,
W.W.L. and Sadovy, Y. (2004). Retrospective
evaluation of data-limited fisheries: a case from
6.12.1.15
CMACS (2003).
A baseline assessment of electromagnetic fields generated by offshore wind farm
cables. COWRIE report EMF – 01-2002 06. Centre for Marine and Coastal Studies,
University of Liverpool.
6.12.1.16 C&E (2000). Record Seizure of Pangolin Scales and Sea Turtle Shells. Customs Intelligence & Liaison Bureau. Customs News, Issue 10. June 2000. Customs and Excise Department, HKSAR Government.
6.12.1.17
Gill, A.B.,
Gloyne-Phillips,
6.12.1.18
Goold J.C.
and
6.12.1.19
6.12.1.20
Hawkins,
A.K. and Chapman, C. J. (1975). Masked
auditory thresholds in the cod, Gadus morhua L. Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and
Behavioural Physiology Vol. 103 (2): 209-226.
6.12.1.21
ITAP (2005). Ermittlung der
Schalldruck-Spitzenpegel aus Messungen der Unterwassergeräusche von
Offshore-WEA und Offshore- Rammarbeiten. Report commissioned by biola (biologisch-landschaftsökologische
Arbeitsgemeinschaft) Institut für technische und angewandte Physik GmbH.
6.12.1.22
6.12.1.23
6.12.1.24
6.12.1.25
6.12.1.26
6.12.1.27
Kastelein, R.A., Bunskoek, P., Hagedoorn, M. and
Au, W.W.L. (2002). Audiogram
of a harbor porpoise (Phocoena phocoena) measured with narrow-band
frequency modulated signals. J. Acoust. Soc. Am. 112, 334-344.
6.12.1.28
Knudsen, F.R., Enger, P.S. and Sand, O. (1994). Avoidance
responses to low frequency sound in downstream migrating Atlantic salmon smolt,
Salmo salar. J. Fish Biol. 45, 227-233.
6.12.1.29
Koschinski,
S., Culik, B.M., Henriksen, O.D., Tregenza, N., Ellis, G., Jansen, C. and
Kathe, G. (2003). Behavioural reactions of free-ranging porpoises
and seals to the noise of a simulated 2 MW windpower generator. Mar. Ecol. Prog.
Ser. 265: 263-273.
6.12.1.30
Leung,
A.W.Y. (2000). Effects on the benthic
fish fauna during and after large-scale dredging in the southeastern waters of
6.12.1.31
Lin, S.Y.
(1949).
The fishing industries of
6.12.1.32
Ni, H.I. and Kwok, K.Y. (1999). Marine Fish Fauna in Hong Kong Waters. Zoological Studies 38 (2): 130-152.
6.12.1.33
NOAA (2008).
Threats to Marine Turtles. NOAA Fisheries Service,
Office of Protected Resources. http://www.nmfs.noaa.gov/pr/species/turtles/threats.htm
6.12.1.34
Parsons, E.C.M. (1997). Hong Kong’s Cetaceans: the Biology,
Socieoecology and Behaviour of Sousa
chinenesis and Neophocaena phocaebiudes. Thesis for the Degree Doctor of
Philosophy.
6.12.1.35
Parsons,
E.C.M. (
Parsons, E.C. M.
(1998b). Strandings of small
cetaceans in
6.12.1.36
Popper,
A.N., Fay, R.R., Platt, C. and Sand, O. (2003). Sound Detection Mechanisms and Capabilities of Teleost Fishes. In:
Collin, S.P. and
6.12.1.37
Popper,
A.N., Plachta, D.T.T., Mann, D.A. and Higgs, D. (2004). Response of clupeid fish to ultrasound: a
review. ICES Journal of Marine Science 61: 1057-1061.
6.12.1.38
Richardson,
W.J., Greene, C.R. Jr., Malme, C.I. and Thomson, D.H. (1995). Marine Mammals and Noise. Academic Press,
6.12.1.39
6.12.1.40
Sadovy,
Y. (1998). Patterns of
reproduction in marine fishes of
6.12.1.41
Sumaila,
U.R., Cheung, W.W.L. and Teh, L. (2007). Rebuilding
6.12.1.42
Teilmann,
J., Tougaard, J. and Carstensen, J. (2006). Summary on harbour porpoise monitoring
1999-2006 around Nysted and Horns Rev Offshore Wind Farms. Report to Energi E
Thomas J,
Chun N, Au W, Pugh K.
(1988). Underwater
audiogram of a false killer whale (Pseudorca crassidens). Naval
6.12.1.43
Thomsen,
F., Lüdemann, K., Kafemann, R. and Piper, W. (2006). Effects of offshore wind farm noise on marine
mammals and fish, biola,
6.12.1.44
Verboom W.C. and Kastelein, R.A. (1995). Acoustic signals by harbour porpoises (Phocoena phocoena). In Nachtigall,
P.E., Lien, J., Au, W.W.L. and Read, A.J. (eds.), harbour porpoises –
laboratory studies to reduce bycatch. De Spil Publishers,
6.12.1.45
Wahlberg, M. and Westerberg, H. (2005). Hearing in fish and
their reactions to sound from offshore wind farms. Mar. Ecol. Prog. Ser. 288: 295-309.
6.12.1.46
Wang, P.
(1984). Distribution of Gray whales in the seas near
6.12.1.47
Westerberg, H. (1995).
Undervattensbuller och fisk. TemaNord 1995:513: 97-109. (in Swedish).
6.12.1.48
Westerberg,
H. (2000). Impact Studies of
Sea-Based Windpower in
Ketten, R.
Bartol, S. (2006) Functional Measures of Sea Turtle Hearing. Woods Hole
Oceanographic Institution Biology Department. Woods Hole, MA
Würsig, B.
and Greene, C.R. Jr. (2002). Underwater sounds near a fuel receiving
facility in Hong Kong: relevance to dolphins. Mar. Env. Res. 54: 129-145.
6.12.1.49
Würsig,
B., Greene, C.R. Jr., Jefferson, T.A. (2000). Development of an air bubble curtain to reduce underwater noise of
percussive piling. Mar. Environ. Res.
49: 79-93.
6.12.1.50
WWF
