An assessment
of the potential environmental impacts associated with the construction and
operation phases of the Project has been conducted in accordance with the
requirements of the Study Brief and EIAO-TM. This EIA study predicted that the Project
would be environmentally acceptable with the implementation of the recommended
mitigation measures. The key
environmental outcomes, taking into account estimated population protected from
various environmental impacts, environmentally sensitive areas protected, environmentally
friendly options considered and incorporated in the
preferred option, environmental designs recommended, key environmental
problems avoided, compensation areas included and the
environmental benefits of environmental protection measures recommended,
are summarised in the following sections.
Environmentally
friendly options and designs as well as various mitigation / control measures
were considered to avoid and / or minimise environmental impacts due to the
construction and operation of the Project.
The following populations and environmentally sensitive areas have been
protected:
n
Areas near Wong Chuk Kok Hoi have
limited access to public transportation and mainly working and transient
populations at nearby country parks and marine parks, Wong Wan FCZ, Outward
Bound Hong Kong, existing and future users of the marine waters in the vicinity
of Wong Chuk Kok Hoi are subject to less potential noise and visual impacts by
the selection of the currently proposed Project site; and
n
All sensitive uses of marine
waters, marine ecological resources and fisheries resources in the Mirs Bay Water Control Zone (WCZ) and the Tolo Harbour and Channel WCZ
have been protected from the potential change in water quality during
construction phase and operation phase.
n Migration
to environmentally friendly modernised mariculture;
n Site
selection to avoid encroachment onto environmental sensitive areas; and
n
Site sitting at deeper waters to
avoid organic accumulation and the need of sediment removal.
AFCD has been actively supporting
the modernization and sustainable development of the local fisheries industry
and enhancing their competitiveness through a multi-pronged approach. Amongst the various measures that have been
recommended, the designation of new FCZs and the promotion of the adoption of
advanced and environmentally friendly culture practices are practical means to promote
mariculture development.
The sustainable development of mariculture and the designation of new
FCZs can have the following benefits:
§ Increase
local mariculture production to support local demand for live marine fish, with
a quality, healthy, safe, diversified and stable supply with low carbon
footprint;
§ Provide
an avenue for capture fishermen, who face various operational challenges, to
switch to a sustainable operation mode, which in turn alleviates local fishing
pressure and promotes the conservation and recovery of fisheries resources and
preservation of the marine environment;
§ Allow
mariculturists of the existing FCZs to consider pursuing modernised and
sustainable modes of operation in the new FCZs, such that the marine
environment of the existing FCZs can improve when the level of mariculture
activities there decreases;
§ Larger
production scale enabled with technology can allow operating costs to be optimised,
and hence improving cost-efficiency and competitiveness;
§ Provide
high value-added fisheries products and assists the fisheries sector to seize
the opportunities in the Greater Bay Area (GBA) and other places;
§ Attract
new entrants and business opportunities to further grow the sector and related
trades organically, also providing employment opportunities.
Overall, the sustainable
development of mariculture in Hong Kong, by means of designating new FCZs,
plays a critical role in fostering support for the fisheries industry which is
an important local cultural asset with a long history and valuable
contributions to Hong Kong’s economy and society. A sustainable fisheries industry will help
establish and maintain marine biodiversity such that our future generations can
enjoy a diverse and rich marine ecological environment.
The criteria for the site selection
of sustainable mariculture were reviewed with reference to international
guidelines (e.g. the Food and Agriculture Organization (FAO)), which include
minimum water depth, wave exposure, water quality and the compatibility with
the existing usage and environment. A
site search using constraint mapping was conducted to identify suitable
locations in Hong Kong waters for the development of new FCZs considering these
site selection criteria. The Project
site is one of the selected sites that have avoided encroaching key marine ecological habitats, including
marine parks and marine reserve, country parks and special areas, SSSIs, coral
communities with high ecological value. The Project is also at some distance away from key marine ecological habitats, including
marine parks and marine reserve, country parks and special areas, SSSIs, coral
communities with high ecological value, mangroves, horseshoe crabs, marine
mammal habitats, wintering or nesting grounds for birds (including
White-Bellied Sea Eagles). Impacts to these marine ecological sensitive
receivers from the potential change in water quality due to mariculture
operation are minimized.
In addition, the Project is at
some distance away from existing, planned / potential marine usages, including
existing FCZs, artificial reefs, coastal protection areas, seawater intake points, designated areas of marine dredging and mud
disposal, existing anchorages, marine vessel fairways, restricted areas,
submarine cables, pipelines and outfalls, private moorings, planned / potential
coastal developments & reclamation, beaches and diving hotspots, thus
potential environmental nuisance from mariculture operation to these marine
usages is minimized.
The Project is at some
distance away from air quality, noise and visual sensitive receivers and thus
environmental impacts to these sensitive receivers are also minimized.
The Project site is located at
deeper waters with water depth of -10 m to -15 m and higher water flushing
rate. Sufficient distance between the
bottom of the fish cage and the seabed as well as among fish cages can be
maintained to minimise water quality impact.
This setting together with the open sea environment allows adequate
water dispersion and prevents the build-up of organic content and degradation
of the nearby marine environment.
Consequently, organic content is also not built up on the seabed and
maintenance dredging and sediment removal are therefore not required for FCZ in
deep waters, and the associated water quality impacts and related ecological
and fisheries impacts can be avoided.
Environmental designs have been
recommended to further minimise the identified environmental impacts. The designs include the followings and each
of them is discussed below:
n Control maximum standing stock level to safeguard
water quality;
n
Adopt modern prefabricated fish
culture raft to minimise on-site construction works and chemical uses;
n
Adopt modern fish farm designs to
lower carbon footprint and waste generation, minimise potential fish escape and
introduction of foreign species to local marine ecological environment; and
n
Adopt fish farm designs and layout
to maintain adequate water flushing.
Carrying capacity (i.e. maximum
standing stock) of the Project site has been determined with well-established
modelling system to ensure environmental sustainability. The modelling system takes into account
factors such as tidal flushing rate of the site, organic and nutrients loading
from fish farms, and the statutory/indicative water quality objectives
applicable to the local waters to determine the carrying capacity of FCZs, thus
providing an objective and scientific assessment on the environmental
acceptability of FCZs. AFCD will limit
the number of marine fish culture license issued to control mariculture
operation at the Project site within the maximum allowable standing stock
level. Impacts on water quality as well
as marine ecological and fisheries resources will therefore be minimised.
A
majority of the framework of the fish cages will be prefabricated off-site, and
then tow the fish farm framework to the Project site for assembly and
anchorage. Prefabrication work off-site
can minimize the construction activities and work duration on-site and hence
reducing the duration when potential impacts to the environment can occur. It is expected to avoid the generation of
C&D materials and chemical wastes, and potential water quality impact from
construction site run-off during the construction of the Project. Generation of underwater sound is minimised
in this method, with less disturbance to marine and fisheries habitats. Also, less labour input required on site
would result in reduction of waste generated from human activities.
Unlike
traditional fish farm designs which are mainly simple designs made of timber,
modernised fish farm designs and the use of advanced mariculture technologies
would minimise environmental impacts.
Modernised fish farm designs are built of weather-resistant materials,
such as high-density polyethylene (HDPE) and the use of steel truss cages are
more durable, which would be less likely to get damaged or repaired and result
in less waste generation. The design of
submersible / semi-submersible fish cage would also be less susceptible to
adverse weather conditions. Advanced
mariculture technologies (e.g. real-time surveillance and water quality
monitoring, renewable energy sources such as solar and wind) and automation
(e.g. fish feeder) can reduce labour intensive activities, hence reduce
potential disturbance to ecology and environment from feed wastage, workforce
wastes, vessel trips, etc.
With
the more durable fish farm building materials, weather-resistant designs and
application of advanced technologies, the impact on marine ecological resources
will be minimised. The introduction of
invasive species and escape of cultured fish are not anticipated with use of
durable fish net / cages, together with the regular maintenance of fish farm
equipment, unacceptable impacts on local ecology and fisheries resources are
therefore not anticipated. Lower carbon
footprint from mariculture operation and less waste generation are also expected
with the use of advanced mariculture technologies.
Commercial
pellet feed or alternative feed with better FCR will
be adopted as the major fish feed at the new FCZ. Pellet feed generally floats on the water
surface that could minimise feed wastage to seabed, thus reducing the potential
pollution loading and minimising impacts to water and sediment quality. On the other hand, pellet feed contains less
moisture (~10%) that can be easily stored at FCZ and minimise the potential
transmission of parasitic and infectious disease to fishes, thus reducing
potential organic waste generation due to feed wastage and fish carcasses and
dead fish arising from the fish culture operation.
Sufficient
separation distance between fish cages and between the cage bottom and seabed
will be maintained to allow adequate water flow in between and reduce impacts
on water quality such as changes in flow regime and build-up of organic
content, reducing the subsequent ecological and fisheries impacts in the
vicinity and degradation of the nearby marine environment. The sizable fish farm cages can also avoid
overcrowding of fish stock and with good mariculture practice and dispersion by
the open sea, organic content is not built up on the seabed. Maintenance dredging and sediment removal are
therefore not required for FCZ in deep waters, and the associated water quality
impacts and related ecological and fisheries impacts can be avoided.
A
summary of the key environmental problems avoided with the environmentally
friendly options (Section 11.3) and recommended environmental
designs (Section 11.4) of the Project is provided in Table 11.1.
Table
11.1 Key Environmental Problems
Avoided, Sensitive Areas Protected and Environmental Outcomes achieved
|
Design
Approach |
Key
Environmental Problems Avoided, Sensitive Areas Protected and Environmental
Outcomes Achieved |
|
Migration to environmentally friendly modernised mariculture |
§ Adverse impacts from mariculture activities to water quality,
marine ecology, fisheries and waste management would be avoided. |
|
Site selection
to avoid encroachment onto environmental sensitive areas |
§ Direct impact from anchorage, assembly and operation of FCZ to
marine ecological resources such as artificial reefs, coastal protection area
are avoided. § Adverse impacts to marine ecology and fisheries due to
encroachment onto environmental sensitive areas would be avoided. |
|
Site sitting at deeper waters to avoid organic accumulation and the
need of sediment removal |
§ Adverse impacts from maintenance dredging and sediment removal
works to water quality, marine ecology and fisheries would be avoided. |
|
Control maximum standing stock level |
§ Adverse impacts from mariculture activities to water quality,
marine ecology and fisheries would be avoided. |
|
Adopt modern prefabricated fish culture
raft |
§ Adverse impacts from on-site construction to water quality,
marine ecology, fisheries and waste management would be avoided. |
|
Adopt modern fish farm designs and advanced mariculture technologies |
§ Adverse impacts from mariculture activities to water quality, marine
ecology, fisheries and waste management would be avoided. |
|
Adopt fish farm designs and layout to maintain adequate water flushing |
§ Adverse impacts from mariculture activities to water quality,
marine ecology, fisheries and waste management would be avoided. |
Appropriate environmental protection measures and mitigation measures
have been recommended to reduce environmental impacts due to the construction
and operation of the Project. The key
measures are summarised in Table 11.2.
Table 11.2 Key Recommended Environmental Protection / Mitigation Measures
and their Associated Benefits
|
Aspect |
Key
recommended environmental protection / mitigation measures |
Associated
Benefits |
|
Water Quality |
§ Standing stock should not exceed
755.2 ton at any given time. AFCD will
ensure the production scale of the Project site will not exceed the maximum standing
stock level by controlling the mariculture production scale permitted under
individual license. § The licensees will adopt the operational measures and best
practice for mariculture activities (see Appendix 2A). § Proper storage and disposal of solid wastes, sewage /
wastewater, chemical wastes and organic wastes shall be carried out under the
relevant Ordinances. § AFCD and mariculturists should be aware of potential occurrence
of low dissolved oxygen at the Project Site by self-monitoring and the
mariculturists will apply suitable control measures (e.g. aeration) as
necessary. § In case of 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. |
§ Protect the neighbouring water sensitive receivers in particular
coral communities. |
|
Marine Ecology |
§ The mitigation measures designed to mitigate water quality
impacts through proper fish farm management shall be adopted. |
§ Minimise impacts to marine ecological sensitive receivers in the
vicinity to the Project site, such as coral communities. |
|
Fisheries |
§ The mitigation measures designed to mitigate water quality
impacts and proper fish farm management designated to mitigate marine
ecological impacts shall be adopted. |
§ Minimise impacts to fisheries sensitive receivers in the
vicinity to the Project site, such as spawning ground and nursery area of
commercial fisheries resources. |
|
Waste Management |
§ Nomination
of approved personnel (e.g. environmental officer of the contractor(s),
representative of the project proponent) to be responsible for good site
practices, arrangements for collection and effective disposal to an
appropriate facility of all wastes generated at the site. § Training
of site personnel in proper waste management and handling procedures by AFCD.
§ Provision
of sufficient waste disposal points and regular collection for disposal. § Appropriate
measures to reduce windblown / floating litter and dust during transportation
of waste by transporting wastes in enclosed containers. § A
recording system (e.g. log book for mariculture operation) for the amount of
wastes generated, recycled and disposed of and the disposal sites for
checking by AFCD. § Prior
to the commencement construction phase and operation phase, training should
be provided to contractor(s) and all staff working at the Project site
respectively. § Proper collection, storage and disposal of solid wastes,
chemical wastes and organic wastes shall be carried out under the relevant
Ordinances. § To
avoid entrapment of floating refuse within the Project site, fish cages /
rafts and vessels should be properly designed to avoid or minimise any
trapped or accumulated refuse. § Use
of good quality feed, i.e. pellet feed, to reduce uneaten feed wastage. § The
fish farmers will keep detailed operational records to allow more accurate
estimation of fish feed input and to minimise unnecessary wastage of feeds. § The
uneaten feeds should be cleaned up immediately to minimise leaching to the
adjacent water. |
§ Minimise waste generation. § Ensure proper handling of wastes by site staff and contractors. |
|
Visual |
§ Pre-construction
and construction period for the Project site should be reduced as far as
practical. § Sensitive
architectural design will be considered where practicable. § Light
intensity and beam directional angle should be controlled at the Project site
at the design stage to reduce light pollution and glare (e.g. hooded lights,
specific directional focus, etc.). In addition,
lighting will be limited to auxiliary structures to reduce night-time
impacts. |
§ Minimise impacts to visual sensitive receivers in the vicinity
to the Project site. § Enhance visual appearance of fish farm during operation. |
|
Cultural Heritage |
§ Implement
a buffer area of 20 m radius from the sonar contact (A-SC001) to avoid tug
boat anchoring, and anchoring of the fish rafts/cages in the areas. § The locations and relocations of fish rafts /
cages are regulated by the Marine Fish Culture Ordinance (Cap. 353), and AFCD
will ensure the locations of anchoring of vessels and fish rafts/cages will
not be located within the buffer area. |
§ Minimise impacts to sites of marine archaeological interest
within the Project site. |
As the
Project
has adopted environmentally friendly options and environmental designs as well
as various environmental mitigation/ control measures, adverse impacts on water
quality, marine ecology, fisheries, waste management, visual and cultural
heritage are not anticipated. Thus,
compensation area is considered not necessary for the Project.