|
Consultancy Ref.: AFCD/FIS/02/19 Consultancy Service
for Environmental Impact Assessment Study for Designation of New Fish Culture
Zones Environmental
Impact Assessment (EIA) Report for Establishment of Fish Culture Zone at Mirs
Bay November
2022 |
This Section presents the findings
of an assessment of potential impacts on existing capture and culture
fisheries, including fisheries resources, fishing operations and fish culture
activities associated with the construction and operation of the proposed
Project with the available Project information to-date.
The criteria for evaluating
fisheries impacts are stated in the Technical
Memorandum on Environmental Impact Assessment Process (EIAO-TM). Annex
17 of the EIAO-TM prescribes the
general approach and methodology for the assessment of fisheries impacts
deriving from a project or proposal, to allow a complete and objective
identification, prediction and evaluation of the potential impacts. EIAO-TM
Annex 9 recommends the criteria that are to be used for evaluating
fisheries impacts.
Other legislation which
applies to fisheries includes:
§ Fisheries Protection Ordinance
(Cap. 171), which provides for conservation of fish and other
aquatic life, regulates fishing practices and prevents activities detrimental
to the fishing industry;
§ Marine Fish Culture Ordinance (Cap.
353), which regulates and protects marine fish culture and
other related activities and requires all marine fish culture activity to
operate under licence in designated FCZs;
§ Water Pollution Control Ordinance
(Cap. 358), which aims to control water pollution in Hong Kong
waters. Water Control Zones (WCZs) are
designated with individual water quality objectives to promote the conservation
and best use of those waters in the public interest; and
§ Environmental Impact Assessment
Ordinance (Cap. 499), the Study Brief Section 3.4.5 and
Appendix D which outline the key fisheries impacts to be reviewed and assessed
in the EIA report.
In accordance with Clause 3.4.5.2
of the Study Brief, the Assessment Area for fisheries impact assessment (Figure
A1.1 of Appendix 5A) shall be the
same as the assessment area for Water Quality Impact Assessment covering the
Mirs Bay Water Control Zone (WCZ) and the Tolo Harbour and Channel WCZ. Detailed description of the physical and
biological characteristics of the marine environment of the Assessment Area is
provided in Section 3 and
Section 4 respectively.
A literature review was
conducted to review the baseline fisheries conditions within the Assessment
Area and to identify information gaps to determine whether field surveys are
required to provide sufficient information for the fisheries impact
assessment. Findings of the literature
review are presented in Sections 5.3.2.1 to 5.3.2.6.
Commercial fishing
operations in Hong Kong are broadly identified into culture and capture
fisheries. Marine-based
culture fishery operations occur at 26 FCZs which altogether occupy about 209
ha of Hong Kong waters with some 920 licensed operators. They involve rearing of marine fish from fry
or fingerlings to marketable size in cages suspended by floating rafts usually
in sheltered coastal areas. Fish farms
are typically small scale operations comprising only one or two rafts with an
average total size of about 304 m2 ([1]).
With effect from June 2002, the
marine fish culture licence is transferable.
The existing moratorium for FCZs has been reviewed and was partially
lifted in 2013 to launch a pilot scheme for the issuance of new marine fish
culture licenses (MFCLs). Ten MFCLs were
issued in three FCZs with surplus carrying capacity, including the O Pui Tong,
Wong Wan and Sham Wan FCZs, in which four licences remained valid, with three
at Wong Wan FCZ and one at Sham Wan FCZ by the end of 2018 ([2]).
In 2021, the marine fish culture
industry produced about 332 tonnes of fish valued at HK$34 million which
accounts for about 2% of local demand for live marine fish ([3]). Some recent figures on the local marine
culture fisheries are presented in Table 5.1.
Table
5.1 Marine Culture Fisheries Summary Statistics
2008-2021 (Source: AFCD)
|
AFCD
Estimate |
2009 |
2010 |
2011 |
2012 |
2013 |
2014 |
2015 |
2016 |
2017 |
2018 |
2019 |
2020 |
2021 |
|
Licensed Mariculturists |
1,050 |
1,035 |
1,010 |
1,008 |
987 |
968 |
969 |
949 |
938 |
931 |
923 |
925 |
920 |
|
Production (tonnes) |
1,437 |
1,512 |
1,185 |
1,299 |
1,005 |
1,255 |
1,219 |
1,031 |
1,004 |
850 |
889 |
687 |
332 |
|
Value (HK$ million) |
92 |
118 |
94 |
117 |
94 |
115 |
105 |
86 |
78 |
71 |
72 |
52 |
34 |
Capture fisheries is vastly
distributed in the waters of Hong Kong, the Pearl River Estuary and the
adjacent continental shelf of the South and East China Seas ([4]). AFCD reported that in 2021 an estimated
112,000 tonnes of fish was produced, which was equivalent to an economic value
of about HK$2.8 billion. Also, 10,510
local fishermen with approximately 5,170 vessels were servicing in the fishing
industry ([5]). The major fishing methods consist of
long-lining, gill-netting and purse-seining.
In 2016-17, AFCD carried out the
latest round of port survey to collect the updated data of distribution of
fishing operations and production for 2016.
According to the survey results, the highest fisheries production of 400
to 600 kg ha-1 in Hong Kong was recorded in the vicinity of the
south of Cheung Chau and Shek Kwu Chau ([6]). The highest number of fishing vessels were
distributed around Soko Islands, Shek Kwu Chau, Cheung Chau, west of Lamma,
northwest of Ninepin Island, Tap Mun and Wong Chuk Kok Tsui. Mullet (Mugilidae), sardine / shad
(Clupeidae), scad / jack (Carangidae), seabream (Sparidae), croaker
(Sciaenidae), squid, crab, rabbitfish (Siganidae), shrimp and flathead
(Platycephalidae) were the top 10 families captured in Hong Kong waters.
To promote the sustainable
development of fishing industry and to conserve fisheries resources in Hong
Kong waters, AFCD has implemented a number of fisheries management and
conservation measures. On 31 December
2012, trawling (including pair, stern, shrimp and hang trawling) was prohibited
to restore the seabed and the decreased fisheries resources ([7]). Other fisheries management practises are
implemented to supplement the ban, including:
§ Setting up a registration system for local fishing vessels;
§ Limiting new entrants to control the fishing effort;
§ Restricting fishing activities of non-fishing vessels and prohibiting
fishing activities of non-local fishing vessels;
§ Designating fisheries protection areas;
§ Habitat enhancement and restoration (i.e. artificial reefs); and
§ Fish restocking trials.
Since 1999, Mainland Authorities
have implemented a fishing moratorium for the South China Sea fishing
ground. In 2022, the revised fishing
moratorium has extended from 1 May to 16 August. The moratorium prohibits all fishing
operations except lining by the Hong Kong fleet outside of Hong Kong waters and
also banning on the operation of fish collectors ([8]) in order to
conserve fisheries resources and promote sustainable development of the fishing
industry ([9]).
Three FCZs are located within the Assessment Area and their
separation distances from the Project site are presented in Table 5.2. The FCZs in the vicinity of
the Project site are Tap Mun FCZ, Kau Lau Wan FCZ and Sham Wan FCZ located over
1 km (by sea distance) away. There are
no fish ponds or oyster farms identified in the northeastern part of Hong Kong
waters (Figure
5.1).
Table
5.2 Distances between the FCZs in the Assessment
Area and the Proposed FCZ at Mirs Bay
|
Fish Culture Zone |
Shortest Separation Sea
Distance (km) |
|
Tap Mun |
2.1 |
|
Kau Lau Wan |
1.4 |
|
Sham Wan |
4.0 |
Trawling has been banned in Hong
Kong waters since 31 December 2012.
Apart from historical data, only some published information after the trawl
ban was available for review.
The most systematic information on
commercial fishing operation and fisheries production of the Assessment Area
was obtained primarily from the AFCD Port Survey 2016/17 (Figures
5.2 to Figure
5.3). The survey was conducted
from 2015 to 2016 through a comprehensive interview survey of local fishermen
by AFCD ([10]). The survey achieved a sampling rate of about
36% which included various fishing vessels from different homeports. Apart from the Port Survey, other recently approved
EIA and fisheries studies undertaken in the Assessment Area have also been
reviewed.
Data
from AFCD Port Survey 2016/17 indicated that the majority of vessels that operated
throughout the Assessment Area were sampans and other vessels including gill
netter, long liner, purse seine etc. were present in smaller numbers. The data indicated that the areas within and
in the vicinity of the Project site has a range of low to high levels (>200-400
vessels, >400-600 vessels and >600-800
vessels) of fishing operations (Figure
5.2). Moderate to high
levels of fishing operation (>400-600 vessels and >600-800 vessels) were
recorded in other areas around the coastline of Kau Lau Wan, Middle Channel,
the majority of Long Harbour and Tap Mun.
Similarly, areas within Hoi Ha Wan Marine Park (HHWMP) also supported
moderate to high level of fisheries operation (>400-600 vessels). Under the Marine Parks and Marine Reserves
(Amendment) Regulation 2019 which came into effect on 1 April 2020, commercial
fishing would be banned and eventually phase out in HHWMP to protect coral
communities and enhance the overall fisheries resources in Hong Kong ([11]). A transitional period of two years is
provided under the ban which new fishing permits will no longer be granted and
existing fishing permits will not be renewed for HHWMP.
Fisheries production of the
Assessment Area in terms of weight as reported in the AFCD Port Survey 2016/17
is presented in Figure
5.3. Results showed that
fisheries production within and in the vicinity of the Project site has low to
moderate (>100-200 to >200-300 kg/ha) fisheries production. Low level of fisheries production (>0-50
kg/ha) was noted at offshore areas of northeastern waters.
Historically, Tolo Harbour was
found to consist of fish assemblages of moderate species richness with low
diversity identified ([12]). It was recorded that the majority of fish
assemblages was fast growing but with low commercial value thriving in heavily
eutrophic waters. The species captured that were considered
of medium commercial value were sea breams, rock fish and chicken grunt ([13]). For south-west Mirs Bay, it was found to
consist of fish assemblages of high diversity and species evenness which
corresponded to the location of the Project site ([14]). However, the lowest species evenness was
recorded at north-west Mirs Bay which was attributed to the majority of the
catch consisting of Ponyfish (Leiognathus
brevirostris).
A more recent review of the
fisheries resources data could be referred to the monitoring of local fisheries
resources from 2010-2015 initiated by AFCD with the implementation of the trawl
ban in 2012. Demersal fisheries surveys
were conducted using stern and shrimp trawlers across four areas in Hong Kong
waters and the results showed that there were signs of recovery of fisheries
resources. In the northeastern waters
relevant to this Assessment Area, it was reported that the abundance and
biomass of seabreams (Sparidae) and hairtails (Trichiuridae), and the abundance
of threadfin breams (Nemipteridae) had increased ([15]). The main commercial fisheries resources
(ranked based on the biomass of each family) found in the northeastern waters
of Hong Kong ([16])
are summarised in Table 5.3 below. Overall, the northeastern waters generally
supported fish families of low commercial value, such as Ponyfish (Leiognathus sp.), with some commercially important families recorded in the area,
such as swimming crabs (Portunidae), seabreams (Sparidae), flatheads
(Platycephalidae) of lower biomass ranking.
A study on Marine Parks and Marine
Reserve fisheries resources in 2016 showed that the abundant fishes in HHWMP
included both fishes of low and moderate commercial values ([17]). The most abundant species in HHWMP was
pearl-spotted spinefoot (Siganus
canaliculatus) which was of low commercial value. Other abundant species in HHWMP included
rice-paddy eel (Pisodonophis boro),
Japanese golden thread (Nemipterus
japonicas), red pargo (Pagrus major),
threadfin porgy (Evynnis cardinalis)
and black bream (Acanthopagrus schlegelii). Among the abundant species, threadfin porgy,
Japanese golden thread, red pargo and black bream were commercially
important. It should be noted that HHWMP
are at some distance from the Project site (>3 km).
Table 5.3 Main Commercial Families of Fisheries Resources
in Northeastern Hong Kong Waters from Fishery Surveys (Source: AFCD Hong Kong
Fisheries Resources Monitoring Report (2010-2015))
|
Rank |
Main Commercial Families
from Shrimp Trawl Surveys |
Main Commercial Families
from Stern Trawl Surveys |
Main Commercial Families
from Purse-Seine Surveys |
|
1 |
Leiognathidae |
Leiognathidae |
Clupeidae |
|
2 |
Platycephalidae |
Clupeidae |
Carangidae |
|
3 |
Portunidae |
Sparidae |
Engraulidae |
|
4 |
Clupeidae |
Carangidae |
Scombridae |
|
5 |
Sparidae |
Polynemidae |
Sphyraenidae |
|
6 |
Gerreidae |
Trichiuridae |
|
|
7 |
Synodontidae |
Siganidae |
|
|
8 |
Squillidae |
Synodontidae |
|
|
9 |
Sciaenidae |
Sciaenidae |
|
|
10 |
Soleidae |
Nemipteridae |
The northeastern Hong Kong waters were previously identified in
1998 as fisheries spawning grounds for various fish species ([18]). In Hong Kong, spawning period
differs among fisheries species with the majority of commercial species
aggregate and spawn in the open waters during June to September. Some fish species, including flathead (Platycephalus
indicus) and shad (Clupanodon (Konosirus) punctatus), spawn in late
winter / early spring (i.e. February to April) and a few are known to spawn in
January. Shrimp scad (Alepes djedaba)
spawns in early summer (around June) whilst pony fish (Leiognathus
brevirostris) and croakers were found to be reproductive throughout most of
the year from May to December. The
spawning period of most of the crustacean species was found to be from April to
November, with spawning concentrated between June and August.
Field surveys were conducted in Tolo
Channel and Long Harbour from May 2016 to May 2017 to investigate the
abundance, composition and distribution of the ichthyoplankton, zooplankton,
juvenile fish and crustacean ([19]). The study recognised the areas as spawning
ground and nursery area which supported a diverse assemblage of fisheries
resource. The ichthyoplanktons of
several commercially important species, such as rockfish
(Sebastiscus marmoratus), seabreams (Acanthopagrus schlegelii, Sparidae
spp.), grunt (Parapristipoma trilineatum), shad (Nematolosa
japonica) and flatheads (Inegocia japonica, Platycephalus indicus),
were recorded in the surveys.
The recognised spawning ground is located
at ~5.9 km from the Project site (i.e. beyond the Assessment Area), covering
Wong Chuk Kok Hoi and extends to the northeastern waters (Figure
5.1). The Project site is
located out of this recognised spawning ground of the northeastern waters (Figure
5.1).
The waters in Tolo Channel and
northeastern Mirs Bay was identified as important nursery areas for high
commercial value species in 1998, which extends approximately 10 km from Wong
Chuk Kok Hoi, covering waters at Tolo Harbour, Tap Mun, Port Island and Long
Harbour (Figure
5.1). This recognised
nursery area is an important habitat for commercial species, namely red pargo (Pagrus major) and the goldlined seabream
(Rhabdosargus sarba) ([20]). The fish fry of Pagrus major have been found to be most abundant during February
and March, whereas juveniles of other commercial species were found abundantly
from July to August. A juvenile fish
survey conducted between 2013 and 2014 identified HHWMP as one of the nursery
areas and the dominant species, such as silverstriped round herring (Spratelloides gracilis), is of low
commercial value ([21]). The Project site is located out of this
recognised nursery area at ~0.7 km away (Figure
5.1).
As mentioned in Section
5.3.2.4, Tolo Channel and Long Harbour were also recognised by a study
conducted between 2016 and 2017 as nursery area which supported a diverse
assemblage of fisheries resource ([22]),
with some commercially important families such as barracuda (Sphyraena flavicauda), jack mackerel (Trachurus japonicus), rabbitfish (Siganus fuscescens) and seabreams (Acanthopagrus schlegelii, Rhabdosargus sarba, Evynnis cardinalis, Pagrus
major) were recorded in the area ([23]).
An Artificial Reef (AR) program has
been implemented in Hong Kong’s waters by AFCD since 1996 as an effort to
enhance fisheries resource whilst promoting biodiversity ([24]). ARs are recognised worldwide as having the
ability to encourage growth and development of a great number and variety of marine
organisms, which in turn provide food, shelter and protection for fishes. Therefore, the ARs are considered to be
fisheries sensitive receivers. There has
been a total of 673 units of ARs with a total volume of over 179,200 m3
([25])
deployed in Hong Kong waters, the location of all ARs deployed is
recorded by the Hong Kong Artificial Reef Project.
There are two AR deployment sites within the Assessment
Area, including HHWMP and Long Harbour (Figure
5.1). No AR has been
deployed within the Project site. The
nearest AR from the Project site would be those deployed at Long Harbour (~2.3
km from the Project site), followed by those deployed at HHWMP (~4.5 km from
the Project site). A total of 6 and 7
units of ARs with a total volume of 33,420 m3 and 9,530 m3
ARs were deployed in Long Harbour from 2002-2004 and in HHWMP from 1998-2003
respectively, to provide hard, bottom, high profile habitat in areas without
natural cover and act as biofilters to enhance habitat quality and marine
resources ([26]).
Based on the baseline information
reviewed, low to high levels of fishing operation with low to moderate levels
of fisheries production were reported at the Project site, and similar levels
of fisheries operation and production were also reported elsewhere in the broad
Assessment Area, which indicates the Project site does not represent a unique
fishing ground. The Assessment Area
including the Project site also supported fisheries resources that are mainly
with low commercial value, and areas that support fisheries of higher
commercial value, such as HHWMP (~4.5 km from the Project site), is located at
some distance from the Project site. ARs
which are key fisheries habitats are also at some distances (>2.3 km from
the Project site) from the Project site.
Annex
9 of the EIAO-TM
states that spawning ground and nursery area can be regarded as important
habitats to fisheries. The Project site
is located out of the recognised spawning ground and nursery area in
northeastern Hong Kong waters.
Identified nursery habitats, such as rocky reefs at HHWMP, are again
located at some distances from the Project Site. The potential for the Project site and its
immediate vicinity to function as a unique and important spawning ground and
nursery area is relatively low.
Based on the preceding review of
the available information on the capture and culture fisheries of the waters in
the vicinity of the proposed Project, the potential sensitive receivers that
may be affected by the Project activities (i.e. distances are shown by sea
distance) are identified as follows:
§ Recognised spawning ground and nursery area of commercial fisheries
resources in northeastern waters which are located at ~5.9 km and ~0.7 km from
the Project site respectively;
§ FCZs at Tap Mun (located at ~2.1 km northwest of Project site), Kau Lau
Wan (located at ~1.4 km west of Project site) and Sham Wan (located at ~4.0 km
southwest of Project site);
§ A total of 33,420 m3 ARs were deployed in Long Harbour (located
at >2.3 km west of the Project site); and
§ Hoi Ha Wan Marine Park (located at ~4.5 km west of the Project site) and
9,530 m3 of ARs deployed within.
The locations of the sensitive
receivers are shown in Figure
5.1.
A review of baseline fisheries
conditions from available literature was conducted for the purpose of
establishing the fisheries importance of the waters in the Assessment Area and
its vicinity. Information
from the water quality impact assessment has been examined to assess
potentially affected area by perturbations to water quality parameters.
The potential impacts due to the
construction and operation of the Project were then identified and evaluated
(with reference to the EIAO-TM Annex 17
guidelines and the criteria in EIAO-TM
Annex 9).
The
construction of the proposed Project will mainly involve the setup of fish farm
structures, including fish rafts / cages, auxiliary facilities and mooring
system. No dredging works is required
during the construction phase.
The scale
of construction work on-site is relatively small. Main components of the rafts / cages are
manufactured off-site and will be towed to the Project site using tug
boat. On-site assembly and anchoring of
the fish rafts / cages will be assisted by a small number of marine vessels
such as sampans and small speed boats for up to a few trips per day. Anchoring of these vessels might be required. No heavy construction plant would be used. Fish rafts / cages and auxiliary facilities,
such as storage space and shelters, would be positioned by anchor lines
attaching to the anchorage points on the seabed. Use of winch might be required during the
assembly and anchorage of fish rafts / cages. All construction activities shall be conducted
during daylight hours.
Potential
impacts to fisheries resources and fishing operations arising from these works
may be divided into those related to:
§ Disturbances of fisheries habitat (including spawning ground and nursery
area) and loss of access to fishing grounds; and
§ Underwater sound from marine construction activities and marine vessels.
Direct impacts to
fisheries resources, habitats and fishing operations include disturbance caused
by assembly and installation activities on-site. The installation
of fish farm structures are expected to be completed within a few weeks for
each fish raft, and would cause temporary
disturbance to fisheries habitat and loss of access to potential fishing
grounds with an area of approximately 410 ha.
Fish farm structures, such as fish cages will occupy a section of the
water column and the disturbance of seabed due to the anchorage of fish farm
structures will be confined to a thin surface
layer (<0.5 m) within a small area.
It should be noted that only a small number of vessels will be used and
the frequency / trip of these vessels would also be relatively low. No disturbance to the identified fisheries
sensitive receivers, including Tap Mun FCZ (~2.1 km from the Project site),
Kau Lau Wan FCZ (~1.4 km from the Project site), Sham Wan FCZ (~4.0 km from the
Project site), and ARs of Long Harbour and HHWMP (~2.3 km and ~4.5 km from the
Project site respectively) is expected.
In the
context of the size of fisheries habitats and fishing
ground available in the vicinity, the size of the area affected would be
small. Considering the temporary nature of the disturbance (a few weeks for
each fish raft / cage), impacts are considered to be of minor significance and
unacceptable impacts on fisheries resources, habitats and fishing activities
are not expected. Fisheries resources
are expected to return to the area following the cessation of fish farm
construction activities.
Construction
activities, such as during the assembly of fish raft, would generate noise,
glare and dust which may affect fisheries resources. Potential impacts, mostly to fish species,
would have temporary avoidance of areas in the vicinity of works area or close
to the source of disturbance.
Considering the temporary nature of the construction works, impacts from
the generation of noise, glare and dust on fisheries habitats are considered
negligible, and unacceptable impacts on the fisheries resources are not
anticipated. Major lighting sources will
be pointed inward and downwards to avoid disturbance to wildlife, unacceptable
impacts on the fisheries resources are not anticipated.
Intermittent sounds, which occur during assembly
and installation activities on-site and marine vessel movement, may have an impact on
fisheries resources. Potential effects
of increased underwater sound include physiological stress, avoidance and
injury (at high pressure levels). The
level of impact is however dependent upon background sound, number and type of
species affected, proximity of organism to the sound source, attenuation
properties of seabed sediments and hearing capabilities of the species
affected, etc..
Most marine invertebrates do not possess air-filled space
and thus it is generally considered that sound would have limited physiological
or behavioural effects on marine invertebrates, except if they are located
within a few metres of the sound source.
Therefore, underwater sound generated from marine works is expected to
have negligible impact on marine invertebrates in the Assessment Area.
The impact of underwater sound generation from
construction activities on fish is highly depended upon the hearing
capabilities of the different species present in the area, with the hearing
specialists being of greatest concern.
The significance of these effects is dependent upon the proximity of
fish to the sound source. Considering
that a small number of marine vessels would be present temporarily at the
Project site during fish farm construction, fish species that are sensitive to
the generation of sound are likely to instinctively avoid the area once works
commence and would be temporarily displaced to other areas where similar
habitat conditions are present.
Fisheries
resources are expected to return to the area following the cessation of fish
farm construction activities.
Waters within the Assessment Area
and its vicinity is subject to a range of low to high levels of marine traffic
by similar types of vessels. It is
reasonable to assume that fish are habituated to low to high background levels
of underwater sound, and a small increase in vessel activity associated with the
construction of this Project is not anticipated to result in unacceptable
impacts on fisheries resources. Overall,
the fisheries sensitive receivers, including Tap Mun
FCZ, (~2.1 km from the Project site), Kau Lau Wan FCZ (~1.4 km from the Project
site), Sham Wan FCZ (~4.0 km from the Project site), and ARs in of Long Harbour
and HHWMP (~2.3 km and ~4.5 km from the Project site respectively), are located
at some distances from the Project site and unacceptable impacts on these
fisheries sensitive receivers are not expected.
Mariculture
activities, such as management of fish raft / cages and fish stocks within the
Project site will be undertaken during operational phase. Limited numbers of small power generators
will be used on fish rafts to support daily mariculture activities. The transportation of fish stocks, fish feed,
fish raft equipment and workforce as well as occasional visitors will make use
of small marine vessels such as sampans and speed boats for a few trips a
day. No maintenance dredging or sediment
removal is anticipated during FCZ operation.
All operation activities shall be conducted during daylight hours. The potential impacts on fisheries of the
Assessment Area include:
§ Changes in fisheries habitats and loss of access to fishing grounds;
§ Temporary relocation of rafts under typhoons or algal blooms;
§ Underwater sound from daily operations and marine vessels;
§ Perturbations to key water quality parameters during fish farm
operation, including fish feed wastage and fish excretion; and
§ Fish diseases.
As
discussed in Section 5.5.1.1, the fish farm structures will not fully occupy
all of the Project site area but mainly a section of the water column and a
small area of seabed confined to a thin surface
layer (<0.5 m). Although the
Project site covers some areas of Mirs Bay, majority of fisheries resources
found in and around the vicinity of the Project site are of low commercial
value. The impacts on fisheries resources and fisheries habitat are
considered to be of minor significance and unacceptable impacts are not
expected.
Fish farm
structures would provide hard substrate that could be colonised by a variety of
marine organisms. Although periodic
cleaning will be implemented as part of the fish farm management practice to
maintain good aquaculture environment, regular cleaning activities will be
mainly applied to fish cages / nets, while the majority of the fish farm
structures, such as the main framework of the fish raft, auxiliary facilities
and mooring system will remain intact most of the time. There is considerable knowledge in Hong Kong
and elsewhere on the colonisation of marine structures with species such as
seaweeds, crustaceans, octocorals, bivalves, amphipods, anemones, bryozoans and
more mobile fauna including crabs.
Colonisation of these structures could attract fish and marine
invertebrates into the area. Overall,
the structures of the fish farm are expected to result in potential positive
effect on fisheries resources and habitats of the waters within and in the
vicinity of the Project site.
All the
fish rafts / cages will be floating with permeable nets to allow water
exchanges with the marine environment.
Consequently, it is predicted that no unacceptable changes in
hydrodynamics will occur.
While the fishing activities in the Project site range
from low to high levels, the area lost for fishing activities (410 ha) is
considered to be moderate compared to the availability of fishing grounds
elsewhere in northeastern Hong Kong waters available for fishing activities.
Overall, the impacts on fishing activities are considered to be of moderate
significance. The Assessment Area including the Project site supported
fisheries resources that are mainly with low commercial value, and areas that
support fisheries of higher commercial value, such as HHWMP, is located at some
distance from the Project site.
Considering that suitable fishing grounds outside of the Project site
can allow similar fishing activities to take place, unacceptable impacts on
fishing activity are not expected.
Operational activities, such as cleaning of fish cages
and the use of lighting, would generate noise, glare and dust which may affect
fisheries resources. Potential impact,
mostly to fish species, would have temporary avoidance of areas in the vicinity
of the operational area or close to the source of disturbance. Considering the temporary nature of the
cleaning activities, impacts from the generation of noise, glare and dust on
fisheries resources are considered negligible, and unacceptable impacts on the
fisheries resources are not anticipated.
Major lighting sources will be pointed inward and downwards to avoid
disturbance to wildlife, unacceptable impacts on the fisheries resources are
not anticipated.
In general,
relocation of fish rafts adopting advanced mariculture technologies are not
necessary under adverse weather (e.g. typhoon) given the framework of fish
cages would use weather-resistant and durable materials (e.g. HDPE cages, steel
truss cages). For other potential
circumstances (e.g. red tide event, outbreak of fish disease), the licensees
will review the need of fish raft relocation and propose the fish raft
relocation plan as necessary for agreement with AFCD on a case-by-case basis,
depending on the type of algal bloom (any toxicity to fish), expected duration
of such circumstances, feasibility for early harvesting of fish stock,
feasibility of implementing onsite control measures etc. In case fish raft relocation is considered
necessary, the fish rafts will be relocated away from the areas of
circumstances, avoid marine fairways and utilities and at some distance away
from ecological and fisheries sensitive receivers (e.g. about 200 m away from
established coral communities) to minimise potential impacts to these sensitive
receivers. Such relocation will be
temporary (e.g. a few weeks) and the fish rafts will return to the Project site
upon the cease of the circumstances. The
mobilisation of the fish rafts will cause temporary disturbance to fisheries
habitat. Increased operation of marine
vessels will occur due to the towing of fish rafts to the new location, and the
re-anchoring of fish rafts will cause temporary disturbance to the water column
and seabed. The corresponding impacts
would be similar to those occurred in the construction phase (Section
5.5.1). Overall, impacts are considered to be of minor significance and unacceptable
impacts on fisheries resources, habitats and fishing activities are not
expected.
Operation of the fish farm would produce underwater sound
from the management of fish rafts / cages and fish stocks, and operation of
marine vessels. The daily operations of
small marine vessels, such as sampans or speed boats would be temporary which
the underwater sound characteristics of these vessels are similar to the
operations at Tap Mun FCZ, Kau Lau Wan FCZ, Sham Wan FCZ and marine traffic at the vicinity of
ferry routes nearby. Fish in these
waters are habituated to the background level of underwater sound, and a small
increase in mariculture and vessel activities associated with the operation of
this Project are not anticipated to result in unacceptable impacts on
fisheries.
Mariculture activities would
result in an increase in water quality pollutants primarily
from fish feed, feed wastage, fish excretion and dead fish. The increase in pollution load would affect the water quality in the receiving waters and the potential impacts on fisheries are as follows:
§ Suspended solids (SS) dispersion;
§ Dissolved oxygen (DO) depletion; and
§ Elevated nutrient levels.
The use and storage of chemicals, such
as pharmaceuticals for fish and those used for equipment maintenance will be
limited on site and stored at secured locations, discharge of water containing
such chemicals is not expected from daily operations. Human activities, such as the removal of
fouling organisms on fish net / cages and the generation of sewage by the staff
on site will be limited. The dislodged
biomass will not be constituted as additional pollution load by feeding on the
original pollution source at the fish farm, and automated / remote operation of
mariculture activities is expected for the new FCZ with minimal manual labour
required. Water quality impacts as a
result from chemical and sewage discharge from the Project site are therefore
not anticipated, and mainly impacts from fish feed, feed wastage, fish
excretion and dead fish are discussed below.
To estimate the impacts on fisheries sensitive
receivers of the Assessment Area, computer modelling of changes in water quality were conducted under two scenarios:
§ Baseline scenario, which covered the “without-project” condition in
2023, including pollution loading from existing FCZs (including Tap Mun FCZ
(~2.1 km from the Project site), Kau Lau Wan FCZ (~1.4 km from the Project
site) and Sham Wan FCZ (~4.0 km from the Project site)); and
§ Project scenario, which took into account the additional pollution load
from the mariculture activities at the Project site, as well as the other
nearby proposed new fish culture zones at Outer Tap Mun and Wong Chuk Kok Hoi
(each at their carrying capacity).
Relevant assessment criteria, i.e. Water Quality
Objectives (WQOs) in the Mirs Bay and Tolo Harbour and Channel WCZs, were then
used to assess potential impacts on fisheries.
Fish farm operation are expected to generate SS within
the water column as a result of fish feed, fish feed wastage and fish excretion,
contributing to an increase in sediment deposition in close proximity of the
Project site.
Fluxes of SS naturally occur in the marine environment
and as a result, fish have evolved behavioural adaptations to tolerate changes
in SS load (e.g. clearing their gills by flushing water over them). Beyond the Project site, dispersion will
cause a rapid decrease in the suspended solids concentrations. Compared to adult fish, larvae and
post-juvenile fish are relatively more susceptible to variations in SS
concentrations as their sensory system is less developed. Adult fish are more likely to move away from
area of disturbance when they detect sufficiently elevated SS concentrations
and therefore are unlikely to be significantly impacted.
The SS level at which fish move into clearer water is
defined as the tolerance threshold which varies among species and different
stages of the life cycle. If SS levels
exceed tolerance thresholds and the fish are not able to move away from the
affected area, the fish are likely to become stressed, injured and may
eventually die. The rate, timing and
duration of SS elevations influence the type and extent of impacts upon fish
and potentially crustaceans.
Findings from literature reviews indicated that lethal
responses had not been reported in adult fish at SS values below 125 mg/L ([27])
and that sub-lethal effects were only observed when levels exceeded 90
mg/L ([28]). However, as part of a study for AFCD, Consultancy Study on Fisheries and Marine Ecological
Criteria for Impact Assessment guideline values have been identified for
fisheries and selected marine ecological sensitive receivers based on
international marine water quality guidelines for the protection of ecosystems ([29]). The AFCD study recommends a maximum SS
concentration of 50 mg/L (based on half of the no observable effect
concentrations). However, the study
cautioned that site-specific data should be considered in environmental
assessments on a case-by-case basis. In
order to provide a more conservative assessment (i.e. with a lower tolerance
criterion), the relevant WQOs for SS elevation are adopted instead in this
study as the assessment criteria for fisheries sensitive receivers.
The water quality modelling results have indicated that
at all fisheries sensitive receivers, SS elevations as a result of fish farm
operation are predicted to be compliant with the relevant WQOs for both wet and
dry seasons. SS elevations are expected
to be temporary in nature and localised to the Project site. With the fish farm standing stock kept within
the Project site’s maximum carrying capacity and the use of pellet feed within
fish farms, potential impacts to fisheries will well managed. The Project site is not located within the
recognised spawning ground and nursery area in northeastern Hong Kong
waters. Areas which supported fisheries
of higher commercial value, such as HHWMP which are at some distance away from
the Project site. As such, unacceptable
impacts from fish farm operation on fisheries resources and habitats (including
spawning ground or nursery area) due to potential elevations of SS are not
expected to occur.
The relationships between SS and DO are complex, with
elevated SS in the water column together with a number of other factors to
reduce DO concentrations. Elevated SS
(and turbidity) reduces light penetration, lowers the rate of photosynthesis by
phytoplankton (i.e. primary productivity) and thus lowers the rate of oxygen
production in the water column. Furthermore,
the decomposition of organic matter in fish feed, fish excretion and dead fish
in the water column may consume DO in the receiving waters. The resulting overall DO depletion has the
potential to cause an adverse effect on the eggs and larvae of fish and
crustaceans, as at these stages of development high levels of oxygen in the
water are required for growth to support high metabolic growth rates.
The water quality modelling results have indicated that DO
depletion associated with fish farm operation are predicted to be low and
remain compliant with the relevant WQO DO criteria at all fisheries sensitive
receivers in the vicinity of the Project Site.
Beyond the immediate vicinity of the Project Site, no unacceptable
change in dissolved oxygen level is predicted at other fisheries sensitive
receivers in both baseline and project scenarios. Overall, there is limited change in the
predicted DO levels at baseline and project scenarios and unacceptable impacts
to fisheries are not expected to occur.
High levels of nutrients released from fish feeds,
fish excretion and dead fish to the water column may potentially cause rapid
increases in phytoplankton population, on occasions to the point that an algal
bloom occurs. An intense bloom of algae can lead to sharp decreases
in the levels of DO. This decrease will initially occur in the
surface water, and then spread to deeper waters as dead algae fall through the
water column and decompose on the seabed. Anoxic conditions may
result if DO concentrations are already low or are not
replenished. As discussed above, reduced levels of DO can impact the
eggs and larvae of fish and crustaceans which require high levels of oxygen for
development. Significantly low levels of DO may also result in fish
mortality.
The water quality modelling results have indicated
that the levels of nutrients as a result of fish farm operation are expected to
be low in general within the Assessment Area.
Predicted levels of unionized ammonia and Total Inorganic Nitrogen (TIN)
at the Project site and all fisheries sensitive receivers are below the
assessment criterion. Overall, the
increased levels of nutrients in the water column as a result of fish farm
operation are considered to be of minor significance and unacceptable impacts
to fisheries are not expected to occur.
Chlorophyll-a
is a photosynthetic pigment of phytoplankton and is commonly used as a direct
indicator of algal biomass. As mentioned
above, increased levels of phytoplankton due to nutrients released from fish
farms could potentially trigger algal blooms, in which could reduce DO levels
in the water column and result in fish mortality.
The water
quality modelling results have indicated that the levels of chlorophyll-a vary
spatially across the Assessment Area and are generally higher at the surface
level and areas with shallower water depth.
The predicted change of chlorophyll-a levels between baseline and
project scenarios at the Project site and all other fisheries sensitive
receivers within the Assessment Area is limited and below the corresponding
assessment criterion. Therefore, fish
farm operation is not expected to result in significant increase of
chlorophyll-a and unacceptable impacts to fisheries are not expected to occur.
Fishes are kept in close proximity
at individual cages in fish farms compared to the open marine waters which will
increase the chance of disease transmission once developed.
It is expected that good mariculture practices shall be
implemented by the fish farmers and preventive measures such as quarantine
newly stocked fish / fry, using uncontaminated fish feed, regular monitoring
and control of fish density, etc., as specified in Appendix 2A. As mentioned in Section 5.5.2.4, if the use of pharmaceuticals for fish is required, it will be limited on
site and stored at secured locations, discharge of such chemicals is not
expected from daily operations. Mariculturists at the Project site would be required to strictly observe
the requirement under Cap. 529 Veterinary Surgeons Registration Ordinance and
have strict control on prescription drugs, therefore, adverse impacts on
fisheries are not anticipated. The implementation of the fish health
surveillance program would also be vital to maintain the health of these
maricultured fish species in the new FCZ ([30]) , therefore, AFCD has
implemented the Fish Health Inspection Programme by conducting regular visits
to fish farms, to identify early outbreaks of fish diseases and advice on good
mariculture practices and prevention measures to fish farmers
as specified in Appendix 2A ([31]).
Unacceptable impacts on fisheries are expected to be minor.
From the information presented above,
the fisheries impacts associated with the Project are not considered to be
significant. An evaluation of the
impacts according to Annex 9 of the EIAO-TM is presented in Table 5.4.
Table 5.4 Evaluation
of Fisheries Impacts in accordance with the Criteria described in Annex 9 of
the EIAO-TM
|
Potential Impact |
Nature of Impact |
Size of Affected Area |
Loss of Fisheries Resources / Production |
Destruction and Disturbance of Nursery and Spawning Grounds |
Impact on Fishing Activity |
Impact on Aquaculture Activity |
Overall Impact Significance |
Mitigation Measures Required |
|
Construction Phase |
||||||||
|
Habitat
disturbances and loss of access to fishing grounds |
Temporary
and short term (a few weeks) in the active works area. |
Loss of
access to fishing grounds would cover the whole Project site (410 ha). |
Project site
is of low to moderate levels of fisheries production and the majority of
fisheries resources is of low commercial value. Considering
that the impacts are temporary, impacts on fisheries resources / production
is minor. |
The
Project site is located out of the recognised spawning ground and nursery
area. No
destructive constructing method are used. The magnitude of disturbance is
considered to be low. |
Low to
high fishing operations have been recorded at the Project site Considering the temporary nature of construction impact, the impacts
on fishing activities are considered to be of minor significance
|
No adverse
impact is expected on Tap Mun FCZ, Kau Lau Wan FCZ and Sham Wan FCZ located
over 1 km from the Project site. |
Minor |
No |
|
Underwater
sound from marine construction activities and marine vessels |
Temporary
and short term (a few weeks) in the active works area. |
Localised
to sound-generating activities, e.g. assembly of fish rafts, installation of
mooring system, marine vessels. |
Avoidance
and habituation by fish are expected.
Loss of fisheries resources / production are considered negligible. |
Underwater
sound is expected to have negligible impact on spawning ground and nursery
area. |
Underwater
sound is expected to have negligible impact on fishing operations. |
No adverse
impact is expected on Tap Mun, Kau Lau Wan FCZ and Sham Wan FCZ located over
1 km from the Project site. |
Minor |
No |
|
Operation Phase |
||||||||
|
Change in fisheries
habitat and loss of access to fishing grounds |
Long term
over Project operation but reversible. |
Loss of
access to fishing grounds would cover the whole Project Site (410ha) |
The fish farm structures only occupy a section of the water column and
a small area of seabed confined to a thin surface layer. Considering that the
majority of fisheries resources is of low commercial value in the Project
site, impacts on fisheries resources / production is minor. Potential
positive effect on fisheries resources due to the colonisation of marine
organisms on fish farm structures is expected. |
The Project site is not located within the
recognised spawning ground and nursery area, therefore no direct impact on
nursery area and spawning ground is expected. Fish farm
structures may potentially provide spawning and nursery habitats. |
Impacts
are localised with moderate impact on fishing operations. Fishing
activities are not allowed at the fish farm structures. Nevertheless, suitable fishing grounds
outside of these structures can allow similar fishing activities to take
place. Therefore, unacceptable impacts on fishing activity are not expected. |
No adverse
impact is expected on Tap Mun, Kau Lau Wan FCZ and Sham Wan FCZ located over
1 km from the Project site. The proposed FCZs would provide more fisheries resources to the local
and global fisheries market. |
Minor |
No |
|
Temporary
relocation of fish rafts / cages |
Temporary. |
Localised
to the immediate vicinity of the area of fish rafts / cages relocation. |
Avoidance by
fish is expected, and negligible loss of fisheries resources when
re-anchoring occurs. |
Impacts
are localised with negligible impact on nursery and spawning grounds when
re-anchoring occurs. |
Impacts
are localised with negligible impact on fishing operations when re-anchoring
occurs. |
Impact is variable depending on the location in
which the fish rafts / cages will be relocated (i.e. distance with other
existing FCZs). Considering that the impact is temporary and the rafts / cages shall
be relocated back into the Project site afterwards, impacts are localised
with negligible or low impact. |
Minor |
No |
|
Underwater
sound from marine vessels and daily operations |
Long term
over Project operation but reversible. |
Localised to
the immediate vicinity of the sound-generating activities e.g. maintenance of
the fish rafts / cages and marine vessel movement. |
Avoidance
and habituation of fish is expected.
Loss of fisheries resources or production are considered negligible. |
Underwater
sound is expected to have negligible impact on spawning ground and nursery
area. |
Underwater
sound is expected to have negligible impact on fishing operations. |
Daily fish
farm operations and marine traffic present at the Tap Mun FCZ, Kau Lau Wan
FCZ, Sham Wan FCZ and Tap Mun pier. Small increase of underwater sound from
the Project site is expected to have no unacceptable impact. |
Minor |
No |
|
Changes in
water quality due to fish farm operational activities |
Long term
over Project operation but reversible. |
Localised
to the immediate vicinity of the fish farm. |
Water
quality compliance expected with no unacceptable impact. |
Water
quality compliance expected with no unacceptable impact. |
Impacts
are localised with negligible impact on fishing operations. |
No unacceptable
water quality impact expected at FCZs. |
Minor |
Water
quality mitigation measures would further reduce impacts. |
|
Fish
diseases |
Infrequent
outbreaks. Occur when source of pathogens / stressors are present. |
Specific fish
rafts / cages or waters in the vicinity of the Project site. |
Magnitude
of impact would depend on the type of disease induced. Proper treatment will be implemented at the
infected sites, therefore the magnitude of impact is considered to be low. |
Magnitude
of impact would depend on the type of disease induced. Proper treatment is implemented at the
infected sites, therefore
the magnitude of impact is considered to be low. |
Impacts
are localised with negligible impact on fishing operations. |
Good
mariculture practices will be implemented, therefore, impact on fish stock
will be minor. |
Minor |
No |
As there
are no other existing or committed non-FCZ projects identified in the vicinity
of the Project site, the Water Quality Impact
Assessment conducted is based on the worst-case scenarios of concurrent
operation of all existing and planned FCZs as sources of pollution. It is expected that all FCZs will be operated
within the maximum carrying capacity and therefore, unacceptable impacts to
water quality are not anticipated.
Consequently, unacceptable cumulative impacts to fisheries resources are
not predicted to occur.
Potential operational impacts presented
in Section
5.5.2 were examined to evaluate potential cumulative impacts with other
operations / developments in the northeastern Hong Kong waters. Outcomes of this evaluation, excluding the
impact on water quality are summarised as follows:
§ Change of Fisheries Habitat and Loss of Access to Fishing Grounds: The change of fisheries habitat and loss of access to fishing grounds
in the context of fisheries operation would be approximately 600 ha in total,
including the Project site (410 ha), the proposed Outer Tap Mun FCZ (55 ha),
the proposed Wong Chuk Kok Hoi FCZ (35 ha) and the proposed Po Toi (Southeast)
FCZ (100 ha). Although the fishing areas
affected covers a certain extent of Hong Kong waters, loss of fisheries
resources and habitats due to all the proposed FCZs would be minimal. Furthermore, the provision of the proposed
FCZs would support more mariculture operations in Hong Kong and thus providing
more mariculture production for local and global consumption. Considering that the overall impact of the
Project is minor, and it is unlikely that the construction and operation of the
Project and the other proposed FCZs would exert an unacceptable cumulative
effect on fisheries.
§ Changes in Water Quality: No marine works or other major source of
pollution is expected from the construction phase of the Project, therefore, no
unacceptable cumulative impact during the construction phase is expected. Water quality modelling results for the
operation phase, including the pollution loading from existing and other
proposed FCZs (i.e. Wong Chuk Kok Hoi FCZ and Outer Tap Mun FCZ) also showed
that no unacceptable cumulative impact during the operation phase is expected.
§ Underwater Sound: This Project is located at
~1.4 km from Kau Lau Wan FCZ, ~2.1 km away from Tap Mun FCZ and ~4.0 km away
from Sham Wan FCZ, and >1.5 km away from other planned FCZs. For this Project, mainly small marine vessels
e.g. sampans and speed boats operated by fishermen would be used during FCZ
operation. The underwater acoustic
profiles generated by works vessels of this Project would therefore be similar
to the daily operations of the Tap Mun FCZ, Kau Lau Wan FCZ, Sham Wan FCZ and
nearby ferry routes. Cumulative effects
of works vessels operational sound, if any, are anticipated to be negligible. It is not expected to result in significant
cumulative impact to the fisheries resources within the Assessment Area.
§ Marine Traffic: This Project is located at
sufficient distance from other FCZs in the vicinity. It is expected to involve a relatively small
number of small marine vessels, such as sampans and speed boats that travel to
and from the Project site during daily operations. Given that existing marine traffic is present
within Outer Tap Mun near Tap Mun FCZ and Tap Mun pier and that the waters off
northeastern Hong Kong have moderate levels of existing marine traffic, such as
the ferry route between Ma Liu Shui to Lai Chi Wo / Kat O and Ma Liu Shui to
Tap Mun, the cumulative effects of marine traffic disturbance to the nearby
fishing operations are anticipated to be negligible.
In accordance with the guidelines
in the EIAO-TM on fisheries impact assessment, the approach adopted in this EIA
includes:
§ Avoidance: Potential impacts should be avoided to the maximum extent practicable
by adopting suitable alternatives;
§ Minimisation: Unavoidable impacts should be minimised by taking appropriate and
practicable measures such as confining works in specific area or season; and
§ Compensation: When all possible mitigation measures have been exhausted and there
are still significant residual impacts or when the impacts are permanent and
irreversible, consideration shall be given to off-site compensation. It may include enhancement of fisheries
resources and habitats elsewhere.
To summarise, this assessment of
impacts demonstrates that impacts will largely be avoided and minimised during
the construction and operation of the proposed Project, particularly to the key
fisheries sensitive receivers, such as the spawning ground and nursery area of
the northeastern waters of Hong Kong, marine parks, ARs and nearby FCZs.
Impacts to fisheries have largely
been avoided and minimised through proper planning and design of the
works. The Project site is selected to
be far from HHHMP, such that impact to the marine park is avoided. The construction work of the FCZ is properly
designed such that no dredging work is required. To minimise the impacts to the vicinity of
the Project site, it is designed to have minimal construction work on site. The scale of construction work on-site is
relatively small, and the number of vessels operating concurrently are limited
to a small number. The installation time
of fish farm structures is minimised and is expected to be completed within a
few weeks for each fish raft which would only cause temporary disturbance to
fisheries habitat and fishing ground.
Main components of the rafts / cages are manufactured off-site and will
be towed to the Project site using tug boat.
On-site assembly and anchoring of the fish rafts / cages will be
assisted by a small number of marine vessels such as sampans and small speed
boats for up to a few trips per day. No
heavy construction plant would be used.
To minimise the impact on fisheries resources, the fish farm is designed
to occupy minimal space which will only occupy a thin surface layer (<0.5 m)
within a small area.
These designs are expected to
control and reduce potential impacts to fisheries resources, and no
fisheries-specific mitigation measures are thus required during
construction.
The mitigation measures designed to
mitigate water quality impacts and proper fish farm management designated to
mitigate marine ecological impacts shall be adopted. No fisheries-specific
mitigation measures are thus required during operation.
Taking into
consideration the impact assessments in the previous sections and with
effective implementation of the proposed mitigation measures, the significance
of residual impacts on fisheries resources including sensitive receivers such
as Tap Mun FCZ, Kau Lau Wan FCZ, Sham Wan FCZ and other ARs in the vicinity
have been evaluated. Residual impacts
occurring as a result of the proposed Project have been determined and are
discussed as follows:
§ 410 ha of fisheries habitat and fishing grounds will be affected during operation
of the FCZ. While the design of fish farm will only occupy a section of the
water column and a small area of seabed. With low commercial value for the
majority of fisheries reosurces found in and around the vicinity of the Project
site and considering that suitable fishing
grounds outside of the Project Site can allow similar fishing activities to
take place, the impact due to the change in fisheries habitat and loss of
access to fishing grounds is considered to be of acceptable. Furthermore, with
the implementation of the proposed mitigation measures, the potential impact on
fisheries will be further minimised. No unacceptable residual fisheries impacts
during the construction and operation of the Project are therefore anticipated.
§ In addition, the establishment of the proposed FCZ would have positive
effects on fisheries resources. While the proposed FCZ would provide more
fisheries resources to the local and global fisheries market, the fish farm
structures would also provide artificial substrates, which could form habitat
and shelter for juveniles or adult fisheries resources. Besides, the reduced
fishing pressure may also have potential positive effect on fisheries resources
within and adjacent to the Project site.
As no
unacceptable impacts have been predicted to occur during the construction and
operation of this Project, monitoring of fisheries resources during these
project phases is not considered necessary.
A review of baseline information on
commercial fisheries resources, habitats and fishing operations surrounding the
waters of the proposed Project from available literature has been
conducted. Results of the review
indicated that although low to high levels of fishing operation with low to
moderate levels of fisheries production were reported at the Project site,
similar levels of fisheries operation and production were also reported
elsewhere in the broad Assessment Area. Recent studies
suggested that the northeastern waters supported fisheries resources that are
mainly with low commercial value, with some commercially important families
recorded in the area. It remains as
important spawning ground and nursery area for fisheries resources. HHWMP which supported fish families with
higher commercial values is located at some distance away from the Project
site. Within the
Assessment Area, fisheries sensitive receivers, including spawning
ground, nursery area, marine parks, ARs and existing FCZs have been
identified. Based on
the information reviewed, the Project site does not represent a unique fishing
ground, spawning ground and nursery area for fisheries resources.
During the construction of the
Project, direct impacts arising from the proposed marine works include
disturbance to fisheries habitats and the loss of access to potential fishing
grounds (~410 ha). Considering the
temporary nature of the disturbance and the majority of fisheries resources
found in and around the vicinity of the Project site are of low commercial value,
unacceptable impacts on fisheries are not expected. Low
to high fishing operations have been recorded at
the Project site. Considering the temporary nature of
construction impact, the impacts on fishing activity are considered to be of
minor significance. Impact of
elevated levels of underwater sound as a result of construction activities are
considered acceptable with the presence of existing underwater sound from the
nearby Tap Mun FCZ, Kau Lau Wan FCZ, Sham Wan FCZ and ferry routes. No
fisheries-specific mitigation measures are required during FCZ construction.
During FCZ operation, there will be
410 ha loss of access to fishing grounds.
The structures mainly occupy a section of the water column and a small
area of seabed confined to a thin surface layer
(<0.5 m). The presence
of fish farm structures will also provide hard substrates that could be
colonised by a variety of marine organisms and bringing potential positive
effect on fisheries resources. Although
the area affected is considered moderate in the context of surrounding similar
habitat, the majority of fisheries resources found in and around the vicinity of the Project
site are of low commercial value, unacceptable impacts on fisheries are not
expected. Impacts
on fishing activity are localized with moderate impact on fishing operation as
fishing activities are not allowed inside fish farm structures. Considering
that suitable fishing grounds outside of these structures can allow similar
fishing activities to take place, unacceptable impacts on fishing activity are
not expected. Potential impacts of
elevated levels of underwater sound generated from the marine vessels in the
vicinity of the Project site are considered acceptable with the presence of
existing underwater sound from the nearby Tap Mun FCZ, Kau Lau Wan FCZ, Sham
Wan FCZ and ferry routes. Temporary
relocation of fish rafts may occur over a short time, therefore, unacceptable
impacts are not anticipated. Impacts of
changes in water quality arising from FCZ operation are predicted to be largely
confined in the vicinity of the Project site within the maximum carrying
capacity. No unacceptable change in
water quality is predicted at all fisheries sensitive receivers in both
baseline and project scenarios. The
management of fish health will be conducted regularly to prevent fish disease
outbreaks, including the Fish Health Inspection Programme to be conducted
regularly by AFCD and the implementation of good mariculture practices by fish
farm owners. No fisheries-specific
mitigation measures are required during FCZ operation.
Overall, no
unacceptable impacts to fisheries are expected to occur. All of the potential construction and
operational fisheries impacts identified are deemed acceptable.
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([8]) Refers to the fisheries ancillary vessels which are used to gather catch from fishing vessels, and operate either in Hong Kong waters or further afield.
([9]) AFCD (2020) Proposed Injection into
the Fishing Moratorium Loan Scheme. Paper presented in Legislative Council
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([12]) Leung
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([16]) South China Sea Fisheries Research Institute (2017) Main Commercial Families of Fisheries Resources in Hong Kong. Prepared for AFCD.
([17]) Country and Marine Parks Board Marine Parks Committee (2020) Fisheries Resources Surveys at Existing and Proposed Marine Parks, and Cape D’Aguilar Marine Reserve – Results and Conclusion.
([18]) ERM
(1998) Fisheries Resources and Fishing Operations in Hong Kong Waters, Final
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([19])
State Key Laboratory of Marine Pollution, City University of Hong Kong
(2018) Provision of Survey Services of Ichthyoplankton, Zooplankton and
Juvenile Fish and Crustacean in the Potential Fisheries Protection Areas. Final Executive Summary, for Agriculture,
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([21]) Leung PTY, Mak S, Ip J, Yau C, Lai V and Leung KMY (2014) Survey of Juvenile Fish Resources at the Three Marine Parks at Northeast Hong Kong. Prepared for Agriculture, Fisheries and Conservation Department, HKSAR Government.
([27]) References cited in BCL (1994) Marine
Ecology of the Ninepin Islands including Peddicord R and McFarland V (1996)
Effects of suspended dredged material on the commercial crab, Cancer magister. in PA Krenkel, J Harrison
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([28]) Alabaster JS & Lloyd R (1984)
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