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 |
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. The following populations and
environmentally sensitive areas have been protected:
n
Areas near Mirs Bay have remote
access to public transportation, mainly residential and transient populations
at nearby Kau Lau Wan, Tap Mun, country parks, marine park and existing and
future users of the marine waters in the vicinity of Mirs Bay are subject to
less potential air quality, 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.
Environmentally
friendly options which have been considered for the Project to minimise
potential environmental impacts include the followings and each of them is
described below:
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. Considering
the potential water quality impact due to mariculture activities of the
Project, the Project is divided into two sub-areas to reduce impacts to the
adjacent environment, including marine ecology and fisheries.
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 -15 m to -20 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 12.3)
and recommended environmental designs (Section 12.4) of the
Project is provided in Table 12.1.
Table 12.1 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 12.2.
Table
12.2 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
5683.5 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. § 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 (C1-SC006) 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.