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:
n
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;
n
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;
n
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
n
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 this 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:
n
Setting up a registration
system for local fishing vessels;
n
Limiting new entrants to
control the fishing effort;
n
Restricting fishing activities
of non-fishing vessels and prohibiting fishing activities of non-local fishing
vessels;
n
Designating fisheries
protection areas;
n
Habitat enhancement and
restoration (i.e. artificial reefs); and
n
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]).
Four FCZs are located within the Assessment Area and their
separation sea distances from the Project site are presented in Table 5.2. The FCZ nearest to the
Project site is Wong Wan FCZ located at ~0.8 km (by sea distance) from the
site. The other FCZs are located >5
km away from the Project site. 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 Wong Chuk Kok Hoi
|
Fish Culture Zone |
Shortest Separation Sea
Distance (km) |
|
O Pui Tong |
5.2 |
|
Sai Lau Kong |
5.2 |
|
Wong Wan |
0.8 |
|
Tap Mun |
5.6 |
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 Wong Chuk Kok Tsui, Tolo
Harbour, Port Island and Tap Mun, while the area in the vicinity of Lai Chi Wo
and within Yan Chau Tong Marine Park (YCTMP) supported low to moderate levels
of fishing operations (>200-400 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 YCTMP 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 YCTMP.
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 is low to
moderate, with >100-200 kg/ha and >200-300 kg/ha production in Wong Chuk
Kok Hoi, waters around Tolo Harbour, Port Island and Tap Mun. 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]).
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) ([14]).
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 YCTMP
and Hoi Ha Wan Marine Park (HHWMP) included both fishes of low and moderate
commercial values ([17]). The most abundant species in YCTMP and HHWMP
were jarbua terapon (Terapon jarbua)
and pearl-spotted spinefoot (Siganus canaliculatus)
respectively which were of low commercial values. Other abundant species in YCTMP included
threadfin porgy (Evynnis cardinalis),
rice-paddy eel (Pisodonophis boro),
striped eel catfish (Plotosus lineatus)
and golden-lined sea bream (Rhabdosargus
sarba); and abundant species in HHWMP included rice-paddy eel, Japanese
golden thread (Nemipterus japonicas),
red pargo (Pagrus major), threadfin
porgy and black bream (Acanthopagrus
schlegelii). Among the abundant
species, threadfin porgy, golden-lined sea bream, Japanese golden thread, red
pargo and black bream were commercially important. It should be noted that both YCTMP and HHWMP
are at some distances from the Project Site (~1.7 km and ~5.1 km respectively).
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
resources. 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 in
northeastern Hong Kong waters is approximately >7 km long covering waters
from the north of Kat O to Wong Chuk Kok Hoi (Figure
5.1). The Project site is
located within the 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
the north of Kat O, covering waters near Port Island, Tap Mun and Tolo 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 the mangrove and seagrass bed
in YCTMP as important nursery areas but the dominant species, such as bald
glassy (Ambassis gymnocephalus), are
of low commercial value ([21]). The Project site is located within this
recognised nursery area (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 three AR deployment sites
within the Assessment Area, including YCTMP, HHWMP and Kat O Fisheries
Station. No AR has been deployed within
the Project site. The nearest AR from
the Project site would be those deployed in YCTMP (~1.7 km away) where a total
of 13 units of ARs with a total volume of ~19,820 m3 were deployed
from 1998-2003 to provide hard, bottom, high profile habitat in areas without
natural cover and act as biofilters to enhance habitat quality and marine
resources ([26]). Other ARs deployed at Kat O Fisheries Station
are considered to be far away from the Project site (>5 km).
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
YCTMP (located at ~1.7 km of the Project site) and HHWMP (located at ~5.1 km away
of the Project site) and ARs deployed within, are located at some distances
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 within the recognised spawning ground and
nursery area in northeastern Hong Kong waters which covers a large area of over
7 km long. Consequently the Project Site
only occupies a very small proportion of the habitats. Key nursery habitats, including the nearest
mangrove and seagrass bed in YCTMP, are again distant from the Project site
(>4 km and >5 km respectively).
The potential for the Project site and its immediate vicinity to
function as a unique 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 are identified as follows:
n
Recognised spawning ground and
nursery area of commercial fisheries resources in northeastern waters which are
located within the Project site;
n
FCZ at Wong Wan (located at ~0.8 km
west of Project site). Other FCZs
which are located >5
km away from Project site;
n
Yan Chau Tong Marine Park (located at ~1.7 km
of the Project site) and the 19,820 m3 of ARs
deployed within; and
n
Hoi Ha Wan Marine Park (located at
~5.1 km away of the Project site) and the 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:
n
Disturbances of fisheries habitat
(including spawning ground and nursery area) and loss of access to fishing
grounds; and
n
Underwater sound from marine
construction activities and marine vessels.
Direct impacts to
fisheries resources, habitats (including spawning ground and nursery area) 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 35 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 Wong Wan FCZ (~0.8 km from the Project site), and ARs of YCTMP and HHWMP (~1.7 km
and ~5.1 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 Wong Wan
FCZ (~0.8 km from the Project site), and ARs of YCTMP and HHWMP (~1.7 km and
~5.1 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:
n
Changes in fisheries habitats and
loss of access to fishing grounds;
n
Temporary relocation of rafts under
typhoons or algal blooms;
n
Underwater sound from daily
operations and marine vessels;
n
Perturbations to key water quality
parameters during fish farm
operation, including fish feed wastage and fish excretion; and
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). In the context of the size fisheries habitats and fishing ground available in the vicinity,
the size of the area affected would be small and the
majority of fisheries resources found in and around the vicinity of the Project
site are of low commercial value, impacts on fisheries resources and fisheries
habitat are considered to be of minor significance and unacceptable impacts on
fisheries resources and fisheries habitat 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.
The
impact from the construction works on fishing activity is of temporary
nature. Furthermore, although part of
the project site is located in an area with high level of fishing activities,
the loss of access to fishing ground is considered to be small compared to the
availability of fishing grounds elsewhere in northeastern Hong Kong waters
available for fishing activities.
Overall, the impacts on fishing activity are of minor significance and
no unacceptable impacts are 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 Wong Wan FCZ
and private mooring site 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:
n
Suspended solids (SS)
dispersion;
n
Dissolved oxygen (DO)
depletion; and
n
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:
n
Baseline scenario, which
covered the “without-project” condition in 2023, including pollution loading
from existing FCZs (including Wong Wan
FCZ (~0.8 km from the Project site), O Pui Tong
FCZ (~5.2 km
from the Project site), Sai
Lau Kong FCZ (~5.2 km from the Project site) and Tap
Mun FCZ (~5.6 km from the Project
site)); and
n
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 Mirs Bay (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.
Suspended Solids
(SS)
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 be well managed. Although the Project site is located within
the recognised spawning ground and nursery area in northeastern Hong Kong
waters, the Project site only occupies a very small proportion of the habitats
and generally supported fish families of low commercial value. Areas which supported fisheries of higher
commercial value, such as YCTMP and 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.
Dissolved Oxygen
(DO)
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 most fisheries sensitive
receivers. Lower DO levels recorded at
the northern areas are likely a result of relatively high pollution loading
from dry weather load and treated sewage effluent from the Starling Inlet (also
known as Sha Tau Kok Hoi), as well as pollution load from Yantian area of
Guangdong. The predicted 10th-percentile
depth-averaged DO levels at both the Project site and Wong Wan FCZ are below
the corresponding assessment criterion.
Such episodes of low DO levels were also observed at Wong Wan FCZ in the
past years without affecting the mariculture operation which are typically
driven by low bottom DO levels in summer months, and the situation at the
Project site is worse than that of the existing Wong Wan FCZ given the higher
water depth. Mariculture operation at
the Project site and other proposed FCZs would result in some change in the
mean and 10th-percentile depth-averaged DO levels. In response to lowered DO levels,
mariculturists could consider providing aeration onsite to improve DO levels at
the fish farm by observing changes in fish behaviour due to low DO levels, and
real-time water quality monitoring device set up by AFCD onsite will also help
to detect signs of low DO levels and inform mariculturists. Additional modelling scenario has been conducted
for the provision of aeration and results indicated that aeration would be able
to replenish DO levels consumed by mariculture operation. Therefore, the predicted reduction in DO
levels at the Project site is expected to be controlled by aeration as
necessary and impacts from DO depletion due to fish farm operation are
considered to be of minor significance.
Outside of the Wong Chuk Kok Hoi embayment, no unacceptable change in
water quality 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.
Nutrients
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 Total Inorganic Nitrogen (TIN) and unionized ammonia
at the Project site and all fisheries sensitive receivers are below the
corresponding 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
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. There is no
change of predicted levels of chlorophyll-a at the Project site and the levels
are below the corresponding assessment
criterion. Outside of the Wong Chuk Kok
Hoi embayment, predicted levels of chlorophyll-a of all fisheries sensitive
receivers within the Assessment Area are also below the 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 (35 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 within the
recognised spawning ground and nursery area. No destructive constructing
method are used. The magnitude of disturbance is considered to be low. |
Moderate 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. |
No adverse impact is expected on Wong Wan,
O Pui Tong, Sai Lau Kong and Tap Mun FCZs. |
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 Wong Wan
FCZ located at ~0.8 km away. Other
FCZs are located >5 km away from the Project site and are considered far
away. |
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 (35ha) |
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 fish farm structures only occupy a
section of the water column and a small area of seabed confined to a thin
surface layer, impacts was considered of minor significance. Fish farm
structures may potentially provide spawning and nursery habitats, the
magnitude of disturbance is therefore considered to be low. |
The loss of access to fishing ground is
also considered to be small compared to the availability of fishing grounds
elsewhere in northeastern Hong Kong waters available for fishing
activities. Suitable fishing grounds
outside of these structures can allow similar fishing activities to take
place. The overall impact is therefore
considered to be minor. |
No adverse impact is expected on Wong Wan,
O Pui Tong, Sai Lau Kong and Tap Mun FCZs. |
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, overall no unacceptable impact is expected. |
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 are present at the Wong Wan FCZ.
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 will be 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:
n
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 (35 ha), the proposed
Outer Tap Mun FCZ (55 ha), the proposed Mirs Bay FCZ (410 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.
n
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. Outer Tap Mun FCZ and Mirs Bay FCZ) also showed that no
unacceptable cumulative impact during the operation phase is expected.
n
Underwater Sound:
This Project is located ~0.8 km away from Wong Wan FCZ and >5 km away from
other existing and planned FCZs. The
cumulative effect of underwater sound will therefore consider the impact from
the nearby Wong Wan FCZ only as other FCZs are far away from the Project site. 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 nearby Wong Wan FCZ and private mooring
site. 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.
n
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 Wong Chuk Kok Hoi near Wong Wan FCZ and the private mooring area, 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:
n
Avoidance:
Potential impacts should be avoided to the maximum extent practicable by
adopting suitable alternatives;
n
Minimisation:
Unavoidable impacts should be minimised by taking appropriate and practicable
measures such as confining works in specific area or season; and
n
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 YCTMP, 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 Wong Wan FCZ have
been evaluated. Residual impacts occurring
as a result of the proposed Project have been determined and are discussed as
follows:
n
35 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 the small
extent of affected area and the overall low commercial value of fisheries
resources, the impact due to the loss of access to fishing grounds is
considered to be of minor significance. 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.
n
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 moderate 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 an important
spawning ground and nursery area for fisheries resources. Areas which supported fish families with
higher commercial values, such as YCTMP and HHWMP are 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 (35 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. Moderate
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 Wong Wan FCZ and private mooring site. No fisheries-specific mitigation measures
are required during FCZ construction.
During FCZ operation, there will be
35 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 bring potential positive effect
on fisheries resources. Considering the
relatively small area affected in the context of surrounding similar habitat
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. The loss of access to fishing ground is also
considered to be small compared to the availability of fishing grounds
elsewhere in northeastern Hong Kong waters available for fishing
activities. Suitable fishing grounds
outside of these structures can allow similar fishing activities to take
place. The overall impact on fishing
activity is therefore considered to be minor.
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 Wong Wan FCZ and private mooring site.
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. Although there are some changes to DO levels
at the Project site due to mariculture operation, the provision of aeration at
fish farms by mariculturists would be able to replenish DO levels consumed by
mariculture operation at the Project site.
Outside of the Wong Chuk Kok Hoi embayment, no unacceptable change in
water quality is predicted at other fisheries sensitive receivers under 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.
([2]) Legislative Council Panel on Food Safety and Environmental Hygiene (2019) Development of Mariculture.
([4]) Sumaila UR, Cheung WWL and Teh L (2007)
Rebuilding Hong Kong’s Marine Fisheries: An Evaluation of Management Options.
Fisheries Centre Research Reports 15 (3). pp.112.
([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 Panel on
Food Safety and Environmental Hygiene.
([12]) Leung
AWY (1997) The epibenthic ichthyofauna of Tolo Harbour and Hong Kong's
Northeastern waters: a long term record of change. In: The Marine Flora and Fauna of Hong Kong
and Southern China IV, Proceedings of the Eighth International Marine
Biological Workshop 1995, B Morton (ed), pp. 463-487, Hong Kong University Press,
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([13]) ERM
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