|
Consultancy
Ref.: AFCD/FIS/02/19 Consultancy Service for Environmental Impact Assessment
Study for Designation of New Fish Culture Zones Environmental
Impact Assessment (EIA) Report for Establishment of Fish Culture Zone at Mirs
Bay November
2022 |
This Environmental Impact
Assessment (EIA) Report has been produced in accordance with the requirements
of the EIA Study Brief (ESB-326/2019) for the Establishment of Fish Culture
Zone at Mirs Bay and the Technical Memorandum on Environmental Impact
Assessment Process (TM-EIAO).
Potential environmental impacts
that have been assessed for the Project include the following aspects and are
summarised in the sections below.
§ Water
quality;
§ Marine
ecology;
§ Fisheries;
§ Waste
management;
§ Visual;
§ Air
quality;
§ Noise;
and
§ Cultural
heritage.
The
summaries of environmental impacts are structured as follows for each of the
technical assessment completed under this EIA study:
§ Sensitive
receivers / assessment points;
§ Assessment
Methodology and Criteria;
§ Key
Construction Impacts;
§ Key
Operation Impacts;
§ Key
Mitigation Measures;
§ Residual
Impacts; and
§ Compliance
with the guidelines and criteria of the EIAO-TM.
Table 13.1
presents a summary of the key findings of the assessment of potential impacts to
water quality as a result of the construction and operation of this
Project. Full details of the assessment
and mitigation measures are presented in Section 3 of this EIA Report.
Table 13.1 Summary
of Environmental Assessment and Outcomes – Water Quality
|
Item |
Description |
|
Water Sensitive Receivers (WSRs) |
WSRs were identified under this Project, covering: n Recreational areas, such as secondary contact recreation subzones of
WCZs; n Marine Park and ARs deployed within; n Existing FCZs, 3 proposed FCZs and spawning ground and nursery area of fisheries resources; n Ecological habitats for marine organisms including coral and benthic
communities, and Finless Porpoise at / near the Project site; n Artificial reefs; n Intertidal area; n Site of Special Scientific Interest; and n Amphioxus habitat; n Non-gazetted beaches. |
|
Assessment Methodology and Criteria |
n The potential impacts due to the construction and
operation of the Project were assessed following the EIAO-TM Annex 6
guidelines and the impacts evaluated based on the criteria in EIAO-TM Annex
14. Water quality impacts on WSRs were
evaluated according to the Water Quality Objective (WQO) criteria of the
corresponding WCZ, additional suspended solids criterion for coral in the
Tolo Harbour and Channel WCZ and chlorophyll-a criterion for FCZs in the Mirs
Bay WCZ. n Construction phase of this Project will only
involve towing; on-site assemble and anchorage of fish raft. The corresponding impacts were assessed
qualitatively. n Impacts due to increase pollution load from
mariculture activities at the Project site at
Mirs Bay were assessed quantitatively using Delft3D suite of model. First, the carrying capacity of the Project site at Mirs Bay was estimated following methodology by Wong et. al. 2012. Project WATERMAN -
Carrying Capacity of Fish Culture Zones in Hong Kong. Then the corresponding pollution load from
the Project site based on the derived carrying capacity, as well
as all the pollution load of fish culture zones were estimated based on the
updated methodology established by Wong
et. al. 2012. This stream of
pollution load, together with other sources of pollutants in HK and the
Guangdong side of the Mirs Bay, were than taken into account in the Delft3D
WAQ modelling simulation to predict the change in water quality at water
sensitive receivers. n The predicted water quality was then assessed
against the relevant criteria of Water Quality Objectives and / or specific
water quality criterion for mariculture for compliance. |
|
Key Construction Impacts |
Impacts during construction
phase of the Project is expected to be very limited. Limited and localized elevation of
suspended solids from anchoring activities will have transient impact on the
water quality because suspended sediment will settle shortly close to the
anchor. The Project
site is deep
enough so propeller wash would not be a concern. Construction phase would likely involve the
use of modular form and pre-treated materials so onsite works and use of
chemicals would be minimal. This also
means there would not be significant presence of workforce onsite. Any sewage / wastewater generated should be
collected by the associated transportation / work boats for disposal at
appropriate facilities on land. |
|
Key Operation Impacts |
n Water quality simulation
indicated that the predicted change in water quality due to the mariculture
operation at the estimated carrying capacity of the Project site would be limited. No
additional exceedance of WQO were predicted at any water sensitive receivers. n The inclusion of integrated
multi-trophic aquaculture would result in different levels of pollution
reduction from the proposed mariculture operation at the Project Site by
means of (1) reduction of wasted feed, fecal matters and other waste, and (2)
filter feeding of plankton and biodeposition.
Its implementation would positively affect the water quality at the
Project Site if implemented in sufficient scale. |
|
Key Mitigation Measures |
Construction: n Any sewage /
wastewater generated should be collected at the transportation / work
vessel(s) for disposal at appropriate facilities on land. Operation: The following precautionary
measures should be implemented to minimise water quality impact from the proposed
mariculture operation at the Project site: n Standing stock should not exceed 5683.5 ton of
standing stock 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. n 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. n Only pellet feed or alternative feed with better
feed conversion ratio will be permitted within the proposed FCZ. n No chemically-laden solution from culture gears
disinfection should be discharged into the sea. n Onsite storage of chemicals should be controlled
and minimized as practicable. Excess
chemicals as well chemical waste generated should be removed from the site at
appropriate facilities or by licensed contractor as soon as possible. n Fuel storage onsite should be minimized, and if
needed, be located at sheltered and secure location. n Littering of the sea should be prohibited. |
|
Residual Impacts |
Construction: n No marine work
or other major source of pollution is expected from the construction phase of
the Project. No unacceptable
construction phase water quality impact is expected. Operation: n Modelling
results indicated no additional exceedance or aggravation of existing
condition would be expected from the operation phase of the Project. No
unacceptable operation phase water quality impact is expected. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts
are in compliance with the EIAO-TM
Annexes 6 and 14 and applicable
assessment standards / criteria. |
Table
13.2 presents a summary of the key
findings of the assessment of potential impacts to marine ecology as a result
of the construction and operation of this Project. Full details of the assessment and mitigation
measures are presented in Section 4 of this EIA Report.
Table 13.2 Summary of Environmental Assessment and
Outcomes – Marine Ecology
|
Item |
Description |
|
Marine Ecological Sensitive Receivers |
In accordance with the Study Brief Section 3.4.4.2
of the Project, the marine ecological sensitive receivers were identified and
detailed in Section 4. n The Assessment Area is the same as the water
quality impact assessment, which covers the Mirs Bay Water Control Zone (WCZ)
and the Tolo Harbour and Channel WCZ. n Known marine ecological important habitats and species in the vicinity
of the Project within the Assessment Areas include existing Country Parks,
Site of Special Scientific Interest (SSSI), existing marine park, mangroves,
seagrass beds, coral communities, marine benthos of conservation interest,
and ecological important species including Amphioxus and White-bellied Sea
Eagle and seagrass
(Halophila
minor). |
|
Assessment Methodology and Criteria |
n A literature review was supplemented by a
programme of field surveys that covered subtidal (benthic and coral)
communities. n The potential impacts due to the construction and
operation of the proposed Project were assessed following the EIAO-TM Annex 16 guidelines and the
impacts evaluated based on criteria in EIAO-TM
Annex 8 and Guidance Notes. |
|
Key Construction Impacts |
n Impacts from temporary habitat disturbance (~410
ha) and underwater sound from marine construction activities and marine
vessels on marine ecology and marine parks is considered minor and
acceptable. Specific mitigation
measures are recommended to avoid disturbance to amphioxus habitat identified
within the Project site. |
|
Key Operation Impacts |
n Impacts from changes in marine habitats
(<410 ha), temporary relocation of rafts due to potential circumstances,
underwater sound from daily operations and marine vessels, changes in water
quality parameters during fish farm operation and potential introduction of
invasive species on marine ecology and marine parks is considered to be minor
and acceptable. n Water quality impacts arising from the
operation of fish farms will be reduced through implementation of recommended
water quality mitigation measures. n Specific mitigation measures are
recommended to avoid disturbance to amphioxus habitat identified within the
Project site. n The operation measures and practices
presented in Appendix 2A would prevent the potential introduction
of invasive species. |
|
Key Mitigation Measures |
Mitigation measures for amphioxus: n The construction and operation of the
Project should avoid any construction and operational works, such as
anchoring of fish farms and FCZ operation at areas identified as amphioxus
habitat (i.e. coarse sediments) within the Project site. The mitigation measures designed to mitigate impacts
to water quality during construction and operation and through proper fish farm
management are expected to mitigate impacts to marine ecological resources. |
|
Residual Impacts |
The following residual ecological impacts have been
identified: n < 410 ha of marine ecological habitat 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
overall low marine ecological value in the context of surrounding similar
habitat, the impact due to the change in marine habitat is considered to be acceptable.
Furthermore, with the implementation of the proposed mitigation measures, the
potential impact on marine ecological resources will be further minimised. No
unacceptable residual marine ecological impacts during the construction and
operation of the Project are therefore anticipated. n In addition, the fish farm structures, which
would provide artificial substrates for forming habitat and shelter for
juveniles or adult fisheries, would provide positive effects on marine
ecological resources within and adjacent to the Project Site. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts are in
compliance with the EIAO-TM Annexes 8 and
16 and applicable assessment
standards / criteria. |
Table 13.3
presents a summary of the key findings of the assessment of potential impacts
to fisheries as a result of the construction and operation of this
Project. Full details of the assessment
and mitigation measures are presented in Section 5 of this EIA Report.
Table
13.3 Summary of Environmental Assessment and
Outcomes – Fisheries
|
Item |
Description |
|
Fisheries Sensitive Receivers Assessment points |
The identified fisheries sensitive receivers are: n Recognised nursery area of commercial
fisheries resources in northeastern waters located within the Project site; n Recognised spawning ground of commercial
fisheries resources in northeastern waters which is ~5.9
km from the Project site; n FCZs at Tap Mun, Kau
Lau Wan and Sham Wan (located at ~2.1
km, ~1.4 km and ~4.0
km by sea distance respectively from Project site); and n Hoi Ha Wan Marine Park and ARs deployed
within. |
|
Assessment Methodology and Criteria |
A literature
review was conducted to establish the fisheries importance of the area
surrounding the Project. The potential
impacts due to the construction and operation of the Project and associated
developments were assessed following the EIAO-TM Annex 17 guidelines and the
impacts evaluated based on the criteria in EIAO-TM Annex 9. |
|
Key Construction Impacts |
n Temporary disturbance to fisheries habitat
and loss of access to fishing grounds within an area of ~410 ha at the
Project site is considered to be minor and acceptable given the small size of
the affected areas and the
majority of fisheries resources found in and around the vicinity of the
Project site are of low commercial value. n While the
fishing activities in the Project site range from low to high levels, the
area lost for fishing activities (410 ha) is considered to be moderate
compared to the availability of fishing grounds elsewhere in northeastern
Hong Kong waters available for fishing activities. Considering that suitable fishing grounds
outside of the Project site can allow similar fishing activities to take
place, unacceptable impacts on fishing activity are not expected. n Due to the presence of low to high
background levels of underwater sound in the vicinity of the Project site,
unacceptable impacts on fisheries due to the generation of underwater sound
from increased marine traffic during FCZ construction is not expected. |
|
Key Operation Impacts |
n Changes in
fisheries habitat and loss of access to fishing grounds will not fully occupy
all of the Project area with the estimated affected area 410 ha. Although the Project site covers a moderate
extent of the area in Mirs Bay, the impact on fisheries resources and
fisheries habitat is
considered to be moderate but acceptable given the majority of fisheries resources found in and
around the vicinity of the Project site are of low commercial value and
suitable fishing grounds outside of these structures are available for
similar fishing activities. n Relocation of fish rafts / cages would
occur only temporarily and corresponding impacts would be similar to the
construction phase. The impact is
considered to be minor and unacceptable impacts on fisheries resources and
habitats are not expected. n Due to the presence of low to high background
levels of underwater sound in the vicinity of the Project site, unacceptable
impacts due to the generation of underwater sound from increased marine
traffic during fish farm operation is not expected. n Unacceptable impacts at all fisheries
sensitive receivers due to changes in water quality from fish farm operation
is not expected. n The implementation of good mariculture
practices and measures presented in Appendix 2A, such as fish health surveillance program
would reduce the outbreak of fish disease, unacceptable impacts on fisheries
are expected to be minor. |
|
Key Mitigation Measures |
The mitigation measures designed to mitigate impacts
to water quality during construction and operation with proper fish
farm management designated to mitigate marine ecological impacts are expected
to mitigate impacts to fisheries resources. |
|
Residual Impacts |
n 410ha of fisheries habitat and fishing
grounds will be affected during operation of the FCZ. While the design of
fish farm will only occupy a section of the water column and a small area of
seabed. With low commercial value for the majority of fisheries reosurces
found in and around the vicinity of the Project site, the impact due to the
change in fisheries habitat and loss of access to fishing grounds is
considered to be of acceptable. Furthermore, with the implementation of the
proposed mitigation measures, the potential impact on fisheries will be
further minimised. No unacceptable residual fisheries impacts during the
construction and operation of the Project are therefore anticipated. 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. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts are in
compliance with the EIAO-TM Annexes 9 and
17 and applicable assessment
standards / criteria |
Table 13.4
presents a summary of the key findings of the assessment of the waste
management implications associated with the construction and operation of this
Project. Full details of the assessment
and mitigation measures are presented in Section 6 of this EIA Report.
Table 13.4 Summary of Environmental Assessment and
Outcomes – Waste
|
Item |
Description |
|
Assessment
Methodology and Criteria |
The study methodology follows the criteria and
guidelines as stated in Annexes 7
and 15 of the EIAO-TM and the Requirements stated in Appendix E of the Study Brief. |
|
Key
Construction Impacts |
General
refuse will be produced by contractor(s) and floating refuse may be trapped
on the surface of the anchored fish cages, fish rafts and vessels within the
Project site during the construction phase.
Unacceptable waste management impact arising from construction of the
Project is not anticipated. |
|
Key Operation Impacts |
Operation waste are mainly comprised of organic
waste, chemical waste, general refuse and floating refuse from site
operation. Operation impacts are
expected to be acceptable with the adoption of appropriate mitigation measures.
|
|
Key Mitigation Measures |
§ 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. |
|
Residual Impacts |
No adverse residual impacts are expected. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts are in
compliance with the EIAO-TM Annexes 7
and 15 and applicable assessment
standards / criteria. |
Table
13.5
presents a summary of the key findings of the assessment of potential visual
impact as a result of the construction and operation of the Project. Full details of the assessment and mitigation
measures are presented in Section 7 of this EIA Report.
Table 13.5 Summary
of Environmental Assessment and Outcomes – Visual Impact
|
Item |
Description |
|
Visual Sensitive
Receivers (VSRs) |
A total
of two VSR groups have been identified. They included recreational and
residential users. Five viewpoints have been selected to assess the visual
impacts. |
|
Assessment
Methodology and Criteria |
n The methodology of the visual impact assessment
was based on Annexes 10 and 18 in the EIAO-TM under the EIA
Ordinance and associated Guidance
Notes. n The visual assessment examined the impact of the
proposed development on the existing views and the visual amenity, particularly
from the VSRs within the viewshed. n In order to illustrate the visual impacts of the
proposed Project structures, photomontages prepared from selected viewpoints
compare the existing conditions with the view after construction. The residual impacts are evaluated
qualitatively, in accordance with the requirements of Annex 10 of the EIAO-TM. |
|
Key
Construction Impacts |
Visual
impacts during construction of the Project are considered acceptable with
mitigation. |
|
Key
Operation Impacts |
Operational
impacts are expected to be acceptable and arise from the operation of the new
structures of the Project site. Night-time lighting for night-time navigation
and glare impact is considered acceptable. |
|
Key
Mitigation Measures |
§ Pre-construction
and construction period for the Project site should be reduced as far as
practical to lower visual impact. § The
new structures will be designed in accordance with relevant marine safety
standards and regulations. Sensitive architectural design will be considered
where practicable. This should take into account material texture, colour,
finishes to structures to ensure the fish rafts / cages blend into the
existing context, cause least disturbance to the existing seascape, and are
the most visually appealing. § After
operation, the open water occupied by the Project site will be reinstated to
their former state. § 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.). |
|
Residual
Impacts |
No
significant adverse visual impacts are expected. |
|
Compliance
with EIAO-TM |
The
assessment and the potential impacts are in compliance with the EIAO-TM Annexes 10 and 18 and applicable assessment standards
/ criteria. |
Table
13.6 presents a summary of the key
findings of the assessment of potential impacts to air quality as a result of
the construction and operation of the Project.
Full details of the assessment and mitigation measures are presented in Section
8 of this EIA Report.
Table
13.6 Summary of Environmental Assessment
and Outcomes – Air Quality
|
Item |
Description |
|
Air Sensitive Receivers (ASRs) |
The Assessment Area is defined as an area within
500m from the Project site boundary as stated in Section 3.4.8.2 of the Study
Brief. No ASR has been identified
within the Assessment Area. Two
nearest ASRs beyond the Assessment Area at over 1 km were identified. |
|
Assessment Methodology and Criteria |
The
principal legislation for the management of air quality in Hong Kong is the Air Pollution Control Ordinance (APCO)
(Cap 311). As the new set of Air
Quality Objectives (AQOs) has come into effect since 1 January 2022, the new
AQOs were used as the assessment criteria for this assessment. A
maximum hourly TSP level of 500 mg m-3 at ASRs is also stipulated in
Annex 4 of the EIAO-TM to assess
potential construction dust impacts.
The measures stipulated in the Air
Pollution Control (Construction Dust) Regulation should also be followed
to ensure that any dust impacts are minimised. Requirements
stipulated in the Air Pollution Control
(Non-road Mobile Machinery) (Emission) Regulation and Air pollution Control (Fuel Restriction)
Regulation will be followed to control potential emissions from non-road
mobile machinery. Requirements
stipulated in the Air Pollution Control
(Marine Light Diesel) Regulation and Air
Pollution Control (Fuel for Vessels) Regulation will be followed to
control potential marine vessel emissions. |
|
Key Construction Impacts |
Minor emissions from small marine vessels and
construction equipment were identified during the construction phase of the
Project. Due to the small-scale
construction works, and sufficient separation distance between the Project
site and the nearest ASR, no adverse air quality impact arising from the
construction works of the Project is anticipated. |
|
Key Operation Impacts |
Minor emissions from small marine vessels and small power
generators were identified during the operation phase of the Project. Due to the small-scale operational
activities, and sufficient separation distance between the Project site and
the nearest ASR, no adverse air quality impact arising from the operation of
the Project is anticipated. |
|
Key Mitigation Measures |
Requirements stipulated in the Air Pollution Control (Non-road Mobile Machinery) (Emission)
Regulation and Air pollution
Control (Fuel Restriction) Regulation will also be followed to control emissions
from construction equipment during construction and power generators during
operation. In addition, requirements
stipulated in Air Pollution Control (Marine
Light Diesel) Regulation and Air Pollution Control (Fuel for Vessels) Regulation will be followed
to control potential emissions from marine vessels. |
|
Residual Impacts |
No adverse air quality impact is anticipated to
arise from the construction and operation of the Project and thus there would
be no residual air quality impact during the construction and operation
phases of the Project. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts are
acceptable and in compliance with the EIAO-TM
Annexes 4 and 12 and applicable
assessment standards / criteria. |
Table 13.7
presents a summary of the key findings of the assessment of potential impacts
to ambient noise level as a result of the construction and operation of this
Project. Full details of the assessment
and mitigation measures are presented in Section 9 of this EIA Report.
Table
13.7 Summary of
Environmental Assessment and Outcomes – Noise
|
Item |
Description |
|
Noise Sensitive Receivers (NSRs) |
In
accordance with Section 3.4.9.2 and
Clauses 2.2.1(a) and 3.2.1(a) in Appendix H of the Study Brief, the Assessment Area for the noise
impact assessment covers areas within 300m of the Project boundary. One NSR
for Country Park was identified within the Assessment Area. A total of three NSRs were identified and
are illustrated in Figure
9.1.
|
|
Assessment Methodology and Criteria |
The
methodology for the noise impact assessment is in accordance with Clause
3.4.9 of the Study Brief and the procedures outlined in the GW-TM, which is issued under the Noise
Control Ordinance (NCO) and the EIAO-TM. |
|
Key Construction Impacts |
One NSR
for Country Park is
identified within the Assessment Area, however, specific noise limit for
Country Parks is not available from relevant legislation and guidelines,
including EIAO-TM and GW-TM. No
adverse construction noise impact is anticipated. |
|
Key Operation Impacts |
In view of the insignificant noise impact arising
from the operation of the Project, no adverse noise impact associated with
the operation of the Project is anticipated. |
|
Key Mitigation Measures |
In view of the insignificant noise impact arising
from the proposed Project, mitigation measures are therefore not required for
both construction and operation phases. Good construction site practice and noise management could be considered
to reduce the noise nuisance from the construction activities as follows: § Only well-maintained plant will be operated on-site and plant
will be serviced regularly during the construction phase; § Silencers or mufflers on construction equipment will be utilised
and will be properly maintained during the construction phase; § Mobile plant, if any, will be sited as far away from NSRs as
possible; § Machines and plant that may be in intermittent use will be shut
down between work periods or will be throttled down to a minimum; § Plants known to emit noise strongly in one direction will,
wherever possible, be orientated so that the noise is directed away from the
nearby NSRs; and § Other structures will be effectively utilised, wherever
practicable, in screening noise from on-site construction activities. |
|
Residual Impacts |
No adverse residual impact is anticipated. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts are in
compliance with the EIAO-TM Annexes 5 and 13 and applicable assessment standards
/ criteria. |
Table 13.8
presents a summary of the key findings of the assessment of potential impacts
to cultural heritage as a result of the construction and operation of this
Project. Full details of the assessment
and mitigation measures are presented in Section 10 of this EIA Report.
Table 13.8 Summary of Environmental Assessment and
Outcomes – Cultural Heritage
|
Item |
Description |
|
Cultural
Heritage Sensitive Receivers |
One sonar contact C1-SC006 that may be of marine archaeological
potential identified in the Assessment Area. Nevertheless, because of the
muddy/silty seabed, objects such as cannon would sink into the seabed, the
sonar contact is most likely to be modern, recently deposited debris that
would not be of high archaeological potential. |
|
Assessment
Methodology and Criteria |
The study methodology follows the criteria
and guidelines as stated in Annexes 10 and
19 of the EIAO-TM and the Requirements for MAI as stated in Appendix I of the Study Brief. |
|
Key
Construction Impacts |
Potential direct impact on sonar contact C1-SC006 that may have marine
archaeological potential is identified due to tug boat anchoring and
anchoring of fish rafts / cages as the seabed will be disturbed by the
anchoring but confined to a thin vertical surface layer (<0.5 m), and
<2m horizontally. |
|
Key Operation Impacts |
Potential direct impact on sonar contact
C1-SC006 due to relocation of fish cages / rafts that may be of marine
archaeological potential is possible. |
|
Key Mitigation Measures |
A buffer area of 20 m radius from
C1-SC006 to avoid tug boat anchoring and anchoring of fish rafts / cages in
the area during construction phase. 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 during
construction phase. AFCD will conduct regular site inspections during operation phase to
check if any seabed disturbance work is conducted in the buffer area. |
|
Residual Impacts |
No adverse residual impacts are
expected. |
|
Compliance with EIAO-TM |
The assessment and the potential impacts
are in compliance with the EIAO-TM
Annexes 10 and 19 and
applicable assessment standards / criteria. |
A
summary of key assessment assumptions, limitation of assessment methodologies
and related prior agreements with relevant Government Departments is presented
in Table 13.9.
Table 13.9 Key Assessment Assumptions, Limitation of
Assessment Methodologies and related Prior Agreement(s) with the Relevant
Authorities
|
Environmental Aspect |
Key Assessment Assumptions |
Limitation of Assessment Methodologies |
Prior Agreement(s) with the Director of Environmental Protection or
other Authorities |
|
Water Quality |
Water quality baseline developed based on
available EPD water quality monitoring data within Assessment Area in
1986-2020. Pollution
loading inventory in Hong Kong was developed based on available planning
data, latest information for sewerage and other infrastructure and followed
the established approach adopted in previous Hong Kong studies. Future
year of 2023 was chosen to develop baseline scenario as the future pollution loading from
the Guangdong Province of China.
Pollution load from the Guangdong Province is expected to decrease
continuously and therefore the estimated loading in 2023 are
assumed for conservative assessment (Section
4 of Appendix
3A
referred). Pollution load from mariculture practice was
estimated based on accepted methodology from previous fish culture zone
studies. A conservative feed
conversion ratio of 2 was adopted for estimation of pollution load. |
Potential
change in pollution loading from Guangdong side of Mirs Bay and potential
change in mariculture practice which leads to different level of pollution
loading from fish farms. Conservative
assumption were adopted to ensure these uncertainties are properly covered. Modelling exercise simulates only typical
conditions of dry season and wet season, which is generally considered
acceptable. |
In accordance with Clause 3.4.3 and Appendix
B of the Study Brief, a Water Quality Modelling Plan was
submitted for agreement by the Director of EPD.
Agreement was received from EPD on 14 October
2022. |
|
Marine Ecology |
Assessment was conducted based with literature
review supplemented with focussed field surveys within the Assessment Area,
including subtidal (benthic and coral) surveys. |
N/A |
Methodology Paper for
Marine Ecological Survey was submitted to AFCD for agreement prior to the
survey. Agreement was received from AFCD
on 25 September 2020. |
|
Fisheries |
Assessment was conducted based on literature
review of past fisheries studies, AFCD’s Port Survey and recent
fisheries surveys of the approved EIA studies. |
N/A |
Methodology
Paper for Fisheries Impact Assessment was submitted to
AFCD for agreement prior to conducting the literature review.
Agreement was received from AFCD on 25 September 2020. |
|
Waste Management |
Volume of general construction and operational
waste were estimated based on the latest design information available from AFCD at the
time of reporting. |
N/A |
N/A |
|
Visual |
Photomontages were prepared with reference to the
typical fish farm. Colours of fish
farm structures may be subject to change at detailed design stage. |
Assessment of magnitudes of change caused by the
Project works to visual sensitive receivers are inherently subjective. |
N/A |
|
Air Quality |
The air quality impact assessment was conducted
qualitatively with reference to the prevailing AQOs and based on the latest
project information provided by AFCD at the time of reporting. |
N/A |
N/A |
|
Noise |
The methodology for the noise impact assessment
is in accordance with the procedures outlined in the GW-TM, which is
issued under the NCO. The construction activities and PME inventory of
the Project are based on latest Project design information provided by
project proponent. |
N/A |
In
accordance with Clause 3.4.9 and Appendix H of the Study Brief,
Methodology Paper for Noise Impact Assessment was submitted to EPD for
agreement prior to the assessment.
Agreement was received from EPD on 9 December 2021. |
|
Cultural Heritage |
The Marine Archaeological Investigation (MAI) was
conducted based on the literature review of past projects and supplemented by
a marine geophysical survey within the Assessment Area to fill in information
gaps. |
N/A |
N/A |
Viable
sites of the Project have been considered during the Project’s Feasibility
Study, based on the environmental benefits and dis-benefits for the
construction and operation of the new FCZs.
Various development options are reviewed and considered in this EIA
study. The environmental benefits and dis-benefits of the development options
and alternative mitigation measures are summarised in Table 13.10. Mirs Bay is one of the proposed sites which
met the selection criteria for new FCZs and is sited to avoid encroaching
sensitive receivers (e.g. ecologically important habitats, areas of high fisheries
importance). To further minimise
potential impacts, the Project site will adopt modernized and advanced type of
aquaculture technologies and operate within the maximum standing stock as
identified in this EIA study.
Table 13.10 Summary of Environmental
Benefits and Dis-benefits of the Development Options and Alternative Mitigation
Measures Considered for the Project
|
Benefits |
Dis-benefits |
|
|
Project
Siting |
||
|
Preferred Option Site selection of sustainable mariculture with
reference to international guidelines, which include minimum water depth,
wave exposure, water quality and the compatibility with the existing usage
and environment |
§ Avoid encroaching into ecological sensitive receivers e.g.
marine reserves, coral habitats of high ecological value and areas of high
fisheries importance, thus avoid impacts to marine ecology and fisheries § Better water flushing rate for mariculture to allow adequate
water dispersion and prevent 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 § Remote area at Mirs Bay minimises impacts on air quality, noise,
and visual sensitive receivers |
§ May pose potential environmental impacts to newly affected
areas. However, careful site selection and fish farm design have been done to
avoid / minimise potential impacts |
|
Alternative Option Expanding existing FCZs |
§ Limit environmental impacts to areas that are already affected
by existing FCZs |
§ Development constrained by existing marine usage and nearby
ecological sensitive receivers. Water flushing rate is generally lower due to
inshore and shallow waters of the existing FCZs. Impacts to water quality, including
restricted dispersion and accumulation of organic loading due to FCZ
operation, are likely to occur when more mariculture production is necessary
to support the development of mariculture in Hong Kong. § Sediment removal may be required periodically to maintain a
suitable environment for mariculture.
The environmental impacts are likely to be more detrimental for FCZs
in inshore areas with shallow water depths.
Alternative mitigation measures such as deployment of silt curtain and
control of dredging rate, etc would be required to minimise the water quality
and marine ecology impact. |
|
Project Size / Scale |
||
|
Preferred Option Establishment of smaller FCZ at different locations |
§ Establishment of smaller FCZs to reduce the organic loading at
individual site, to minimize impact to coral communities and habitat for
marine ecological and fisheries resources. § With sufficient clearance to navigation routes, accidents /
collision of marine vessels with fish farm facilities, and potential risk of
fish escape and introduction of invasive species to the marine environment
can be minimised. |
§ Affect more areas with potential environmental impacts but
better control of impact intensity to within relevant criteria |
|
Alternative Option Establishment of a single larger FCZ |
§ Limit environmental impacts to single location but with higher
intensity |
§ The pollution loading from mariculture operation will
concentrate in a particular area. The potential impacts to water quality,
marine ecology and fisheries of the surrounding waters are expected to
increase. |
|
Fish Farm Layout and Design |
||
|
Preferred Option Use of advanced mariculture fish farm
designs (e.g. HDPE cages, steel stuss cages) |
§ Durable and weather-resistant material would less likely to get damaged
or repaired and result in less waste generated. § Less susceptible to damage during adverse weather condition,
such as typhoons, and minimise potential risk of fish loss / escape, and
subsequent impact on local ecology and fisheries; and also minimise impact
due to fish cage relocation. § Adequate water flow and dispersion of organic content between
cages / rafts, and along the water column is allowed. Adequate clearance from seabed will also be
maintained. Water quality impacts such
as changes in flow regime and build-up of organic content are minimised. Subsequent ecological and fisheries impacts
in the vicinity and degradation of the nearby marine environment could be
reduced. The need for maintenance dredging and
sediment removal during construction and operation of the Project is also
avoided. § Use of green technology and automation could reduce feed wastage
and physical labour,
hence reduce potential disturbance to water quality, ecology and environment
from feed wastage, workforce wastes, vessel trips, etc. |
§ Higher setup cost |
|
Alternative option Use of traditional fish farm designs (e.g. made of timber supported by floating units made of empty plastic drums or
polystyrofoam floats) |
§ Lower setup cost |
§ Non-weather resistant materials and easy to get damaged or
repaired. More wastes are expected to
be generated. § Susceptible to damage from adverse
weather conditions such as typhoons. Potential risk of fish loss / escape is higher, and subsequent
impact on local ecology and fisheries; and also impact due to fish cage
relocation would increase. §
Potential
impact on water flow and dispersion of organic content between cages / rafts,
and along the water column might be present, and result in the build-up of organic
content on seabed. Maintenance dredging and sediment
removal may be required periodically and water quality impacts would
arise. Subsequent ecological and fisheries impacts in the vicinity and
degradation of the nearby marine environment would also increase. Other mitigation measures will be required
to control and minimise impacts to water quality, such as the use of silt
curtains, closed grab dredger, etc. § Require more labour input and hence increase potential
disturbance to ecology and environment from feed wastage, workforce wastes,
vessel trips, etc. |
|
Construction Methods and Sequence of Works for the Project |
||
|
Preferred option Fish farm framework are
pre-fabricated off-site, then assemble and anchored on-site |
§ Minimisation of construction duration on-site and hence reducing
the duration when potential impacts to the environment can occur. § No generation of C&D materials on-site and potential water
quality impact from construction site run-off during the construction of the
Project is avoided. The use of silt
curtain and construction boats for silt curtain deployment are therefore not
required, the subsequent impacts to marine and fisheries habitats such as
underwater sound from marine vessels are minimised § Less labour input required on site would result in reduction of
waste generated from human activities |
§ N/A |
|
Alternative option No alternative option applicable as
the fish farm framework used for advanced type of mariculture is large in
scale, and could not be constructed from raw materials on site. |
§ N/A |
§ N/A |
The
construction and operation activities of the proposed Project has been
demonstrated in this EIA Report to comply with the EIAO-TM
requirements. Actual impacts during the
construction and operation activities will be monitored through a detailed
Environmental Monitoring and Audit (EM&A) programme. Full details of the EM&A programme are
presented in the EM&A Manual attached to this EIA
Report. This programme will provide
management actions and mitigation measures to be employed should impacts arise,
thereby ensuring the environmental acceptability of the construction and
operation activities of this Project.
No
unacceptable residual impacts have been predicted for the construction and
operation activities of this Project. It
must be noted that for each of the components assessed in the EIA Report, the
assessments and the residual impacts have all been shown to be acceptable and
in compliance with the relevant assessment standards/criteria of the EIAO-TM
and the associated Annexes.