This Section of the EIA Report presents the findings
of an impact assessment on existing fisheries resources, capture and culture fishing
operations from the construction and operation of the proposed offshore wind
farm development. The assessment is
based on the Project Description (Section
5) and the findings of the Water Quality Assessment (Section 6). For a
description of the physical and biological characteristics of the marine
environment of the Study Area please refer to Sections 6 and 9,
respectively.
10.2
Legislative
Requirements and Evaluation Criteria
The criteria for evaluating fisheries impacts
are laid out in the EIAO-TM. Annex
17 of the EIAO-TM prescribes the
general approach and methodology for the assessment of fisheries impacts
arising from a project or proposal, to allow a complete and objective
identification, prediction and evaluation of the potential impacts. EIAO-TM
Annex 9 recommends the criteria that are to be used for evaluating
fisheries impacts.
Other legislation which applies to
fisheries includes:
·
Fisheries Protection Ordinance (Cap
171) 1987, which provides for the conservation of fish and other aquatic life,
regulates fishing practices and prevents activities detrimental to the fishing
industry.
·
Marine Fish Culture Ordinance (Cap
353) 1983, which regulates and protects marine fish culture and other related
activities.
·
Environmental Impact Assessment Ordinance
(cap. 499), Section 5(7) - Environmental Impact Assessment Study Brief no.
ESB-126/2005 Section 3.4.6, which outlines the key fisheries
impacts to be reviewed and assessed in the EIA Report.
10.3
Baseline
Conditions and Fisheries Sensitive Receivers
The Study Area was the same as that for the Water
Quality Impact Assessment (see Section 6). This area considers a range of fisheries
sensitive receivers within 7 km of the wind farm site and cable route,
including spawning and nursery areas and Fish Culture Zones.
10.3.1
Overview of
In
In 2008, the
Since 1999, Mainland Authorities have implemented a
fishing moratorium for
The impact
assessment included in this Chapter is based upon recent data that has recorded
fishery activity at the proposed wind farm site (including associated
infrastructure) and along the proposed cable route.
Mariculture fishery operations occur at 26 fish
culture zones (FCZs), occupying about 209 ha of
Table 10.1 Marine
Culture Fisheries Summary Statistics 1999 - 2008 (source: AFCD)
|
|
1999 |
2000 |
2001 |
2002 |
2003 |
2004 |
2005 |
2006 |
2007 |
2008 |
|
Licensed Mariculturists |
1,454 |
1418 |
1320 |
1237 |
1157 |
1125 |
1104 |
1081 |
1072 |
1060 |
|
Production
(tonnes)* |
1250 |
1770 |
2470 |
1210 |
1490 |
1540 |
1540 |
1490 |
1530 |
1,370 |
|
Value (HK$
million)* |
66 |
102 |
136 |
57 |
76 |
79 |
76 |
89 |
99 |
82 |
* AFCD estimates
No FCZs are
located close to the wind farm site or the proposed cable route. The closest FCZs
are located at Lo Tik Wan (> 9 km from the windfarm site, > 6 km from the cable route), Sok Kwu
Wan (> 10 km from the windfarm site, > 8 km
from the cable route) and Cheung Sha Wan (> 10 km
from the windfarm site, > 9 km from the cable
route) (see Figure 10.1).
10.3.3
Capture Fisheries
Based
on the latest AFCD Port Survey data (i.e. 2006), the highest fisheries
production (600 to 1,000 kg ha-1) in Hong Kong occurred near the
Ninepin Island Group, Po Toi and Tap Mun. The top 10
families captured in
Fishing Vessels
The scale of fishing operations in terms of
the number of vessels operating in the waters around the proposed wind farm
site and cable route is presented in Figure 10.2.
With reference to the AFCD grid system and
the findings of the Port Survey 2006, the number of vessels that operate in
waters at
It is interesting to note that the use of
these waters by trawling operations is also apparent from the results of the
geophysical surveys conducted as part of the site investigation and marine
archaeological surveys works (see Section
12). Numerous trawl scars
within the study area are clearly evident from the results of these surveys and
support the finding that such activities are present in these waters.
In addition, to the desk-top review,
opportunistic vessel-based observations
have been made of active fishing vessels in the survey area in parallel
with bird and marine mammal surveys that were undertaken for this EIA (see Sections 8 and 9). These surveys are,
however, only meant to be supplementary to more robust and quantitative surveys
carried out as part of the AFCD Port Survey. The survey followed the same transects
as that bird and marine mammal surveys as shown in Figure
10.3
(see Sections 8 and 9). Observational records were taken from
July to October 2008 and January to June 2009. Records were therefore taken over a 10
month period. A total of 6
different types of fishing vessel were recorded with a mean total number of ~10
vessels sighted in Study Area per day (Table
10.2). The results would
therefore suggest that during the period of observation fishing activity in the
wind farm area was comparatively lower than areas to the north,
west and east of the wind farm (see Figure
10.2). The results from the vessel sighting
records suggest that the predominant type of vessels moving across the wind
farm site and cable route during the period of observation were small P4s ([3]) undertaking hand
lining or gill netting activities, followed by shrimp trawling and stern
trawling vessels. The data would
also seem to confirm that greatest trawling activity occurs to the east of the
wind farm site around the south and east of
Although the results are noted as being
based on opportunistic observational surveys, it is interesting to note some of
the differences between these surveys and the AFCD Port Survey findings. On note are what appear to be lower
levels of usage of these waters by trawling vessels and the high levels of
small scale hand lining fisheries such as those observed on P4s. Overall the findings may indicate that
from this newer data, the waters around the study area are less intensively
fished by certain gear types than that previously recorded in other years.
Table 10.2 Type
of fishing vessels, total number of vessel sights for each month from July 2008
to June 2009 and the mean number of vessel sightings per day
|
|
Total Number of Vessels Sighted |
Mean per day* |
|
|||||||||
|
Vessel type |
Jul3 |
Aug3 |
Sept3 |
Oct3 |
Jan1 |
Feb2 |
Mar3 |
Apr3 |
May3 |
Jun3 |
|
|
|
Hang Trawler |
3 |
2 |
0 |
0 |
0 |
0 |
0 |
2 |
2 |
2 |
0.2 |
|
|
P4 |
44 |
18 |
21 |
9 |
4 |
21 |
35 |
30 |
48 |
22 |
5.6 |
|
|
Pair Trawler |
2 |
2 |
1 |
0 |
0 |
0 |
0 |
1 |
1 |
4 |
0.2 |
|
|
Shrimp Trawler |
14 |
6 |
9 |
7 |
0 |
8 |
12 |
12 |
10 |
11 |
2.1 |
|
|
Stern Trawler |
10 |
8 |
6 |
7 |
1 |
6 |
1 |
8 |
7 |
6 |
1.4 |
|
|
Gill Netter |
2 |
2 |
4 |
0 |
0 |
0 |
2 |
6 |
4 |
4 |
0.9 |
|
|
Total |
75 |
38 |
41 |
23 |
5 |
35 |
50 |
59 |
72 |
49 |
9.9 |
|
|
1
One sampling day in the month of survey |
||||||||||||
|
2
Two sampling days in the month of survey |
||||||||||||
|
3
Three sampling days in the month of survey |
||||||||||||
Fisheries Production
The level of fisheries production in the waters
around the site is presented in Figure 10.4.
Adult
fish catches vary from 400 – 600 kg ha-1 and 200 – 400 kg ha-1
within and immediately adjacent to the wind farm site and cable route. In comparison to other areas of the
Fish Fry Production
As presented in Figure
10.5,
there is no record of fish fry catches within the proposed wind farm and cable
route. Inshore areas at around
Catch Value
The
value of catches from the waters around the proposed wind farm is presented in Figure
10.6. The overall catch value of both adult
fish and fish fry recorded for the waters at the site was in the range of
HK$2,000 – 5,000 ha-1 and up to HK$ 5,000 – 10,000 ha-1. The value of catches to the east of the
proposed wind farm site and along the cable route is relatively high. Again, the value of catches is also high
outside of the wind site around
Fisheries Resources – Spawning and Nursery
Areas
Spawning
Area: In 1998, the southern waters of
The proposed
Nursery Area: Nursery
areas in Hong Kong waters that are important habitat area for a number of
commercial juvenile fish and crustacean species have been previously identified
to extend across southern waters from
Fisheries Importance
The importance of the fisheries resources
within the Study Area is addressed based on the baseline information provided
above. The fishing areas within and
adjacent to the wind farm site are of medium-high commercial value.
The EIAO-TM
(Annex 9) states that spawning and nursery grounds can be regarded as an
important habitat type as they are critical to the regeneration and long-term
survival of many organisms and their populations. However, as shown by the Port Survey
data there are no recorded fish fry catches in the Project area. In addition, the area of marine waters
within the wind farm site represents a small fraction of identified spawning
and nursery grounds in Hong Kong, which have been reported to encompass the majority of
The impact assessment is concerned with
fisheries activity in
10.4
Fisheries Impact
Assessment Methodology
A desktop literature review was conducted in order to
establish the fisheries importance of the area surrounding the proposed wind
farm and cable route. This was
supplemented by opportunistic fishing vessel observations undertaken in
parallel with marine mammal and bird surveys. However, desk-top literature is seen as
the primary data for determining impacts.
The importance of potentially impacted fishing
resources and fisheries operations identified within the Study Area was
assessed using the approach described in the EIAO-TM. The potential
impacts due to the construction and operation of the Project and associated
developments were then assessed (with reference to the EIAO-TM Annex 17 guidelines) and the impacts evaluated (with
reference to the criteria in EIAO-TM Annex 9).
10.5
Identification of
Fisheries Impacts
The construction activities associated with the
proposed Project that have the potential to cause impacts to fisheries are:
·
Installation
of wind turbine and wind monitoring mast foundations; and
·
Installation
of the submarine cables.
Construction phase impacts to fisheries resources and
fishing operations arising from the construction works of the proposed wind
farm may be divided into those due to direct disturbances to that habitat and
those due to indirect perturbations to key water quality parameters and
underwater sound.
Direct Impacts
Disturbance of seabed
habitats
The construction of the seabed foundations will lead
to the disturbance of 0.16 ha of marine habitat. Although installation will also result
in disturbance of seabed through scour protection, these areas will be
reinstated as habitat for fisheries resources prior to operation hence are only
considered to be a temporary loss. The seabed at the wind farm site is common
to
Though a larger area of the seabed is impacted by the
dredging and jetting activities for cables installation, it is expected that
the temporary nature of the interference will not cause significant impacts on
the fishery resources and fishing operations. In addition, fisheries resources are
expected to return to the area following the cessation of cable installation
activities.
Due to the small area of the marine habitat disturbed
in comparison to available habitat elsewhere of similar or equal fisheries
importance, impacts to local fisheries resources are considered to be of minor
significance.
Access to the site
During construction, the offshore working area will
need to be established and marked in accordance with Marine Department Notice No. 23 (2009). A safety / exclusion zone of 500 m will
be closed to all vessels around the area of works. The purpose of this area
will be to protect the safety of construction plant and personnel and also
third parties who may wish to navigate through this area. This safety zone will cover the whole
wind farm area, but the extent of the safety zone will change as per the
rolling construction programme. The
imposition of the safety zone will mean that fishing activity will be excluded
from these areas whilst construction is ongoing. These impacts will, however, be short
term and be related to relatively small areas where works will be undertaken. In addition, the level of fishing
activity within the majority of the areas where works will take place is not
high and there is suitable habitat away from these areas for similar activities
to take place. Impacts are
therefore considered to be of minor significance.
Increased Vessel Traffic
The construction of the wind farm and cable route
will require the use of marine vessels, including a jack-up barges, tug, safety
vessel and personnel transfer vessel.
This will increase traffic flow in the area with the potential for
increase collisions risk. However,
the development of a safety / exclusion zone 500 m from any area of works and
other notifications as set out in Section
10.7 will mean that increased risk of collision will be very low.
Indirect Impacts
Indirect impacts to fisheries resources and fishing
operations during the construction phase are primarily associated with the
suspension of sediments due to the marine works. Potential impacts to water quality from
sediment release are listed below:
·
Increased
concentrations of suspended solids (SS);
·
Decrease
in dissolved oxygen (DO) concentrations;
·
Increase
in nutrient concentrations in the water column;
·
Potential
for contaminant release; and
·
Underwater
sound generated from marine construction activities.
Suspended Solids:
Suspended solids (SS) fluxes occur naturally in the marine environment;
consequently, fish have evolved behavioural adaptations to tolerate changes in
SS load (e.g., clearing their gills by flushing water over them). However, the increase in suspended
solids concentrations that would arise from the foundation installation,
jetting and dredging would be uncharacteristic of the normal variable marine
conditions. Beyond the active
construction areas, dispersion will cause a rapid decrease in the suspended
solids concentrations.
Larvae and post-juvenile fish are more susceptible to
variations in SS concentrations than more mature fish since their sensory
system is less developed. Adult
fish are more likely to move away when they detect sufficiently elevated
suspended solids concentrations and therefore are unlikely to be significantly
impacted. Larvae and post-juvenile
fish are more likely to be impacted as they may not be able to detect and avoid
areas with elevated levels of SS.
The SS level at which fish move into clearer water is
defined as the tolerance threshold and varies from species to species at
different stages of the life cycle.
If SS levels exceed tolerance thresholds and the fish are unable to move
away from the area, the fish are likely to become stressed, injured and may
ultimately die. Susceptibility to
SS generally decreases with age such that eggs are the most vulnerable and
adults the least sensitive to the effects of high SS concentrations. The rate, timing and duration of SS
elevations will influence the type and extent of impacts upon fish and
potentially crustaceans ([5]).
Literature reviews indicate that lethal responses had not been reported
in adult fish at values below 125 mg L-1 ([6]) and that sublethal
effects were only observed when levels exceeded 90 mg L-1 ([7]).
Modelling has show that temporarily elevated levels
of SS are likely to occur as a result of marine construction works. However, the largest impacts are
expected in the immediate vicinity of the marine construction works (in the
mixing zone) with impacts on the wider marine environment are expected to be
very low or nil (see Table 6.9 in Section 6.6.1). Grab dredging works would only lead to
increased suspended sediments directly adjacent to the Lamma
Power Station Extension over two days.
Indeed, no impacts from dredging are noted within an area of
approximately 1km of dredging works.
Although, the Lamma Power Station Extension
seawall supports some isolated coral colonies, these are of low conservation
value and are not expected to act as important spawning or nursery
grounds. For dredging activities,
elevated SS levels only occur in the localised mixing zone and do not extend
far beyond this point (see Table 6.9 in Section 6.6.2). Very minor impacts were noted in open
water adjacent the cable route and around the nearshore
zones of
Sediment testing has also determined that
unacceptable water quality impacts due to the release of heavy metals and
organic micro-pollutants associated with suspended sediments will not occur
(see Section 6.6.5).
Negligible impacts on fisheries associated with
increased SS are therefore expected.
Dissolved Oxygen:
The relationship between SS levels and DO is complex. However, in general, elevated SS (and
turbidity) reduces light penetration, lowers the rate of photosynthesis by
phytoplankton (primary productivity) and thus lowers the rate of oxygen
production in the water column.
Furthermore, the potential release of sediment contaminants into the
water column has the potential to consume DO in the receiving water. The resulting overall DO depletion may
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 results of the water quality assessment (see Section 6) examining dispersion of
sediment plumes associated with the proposed marine construction works have
shown that the predicted elevated levels of SS are minor, localised to the
mixing zone and transient. The
calculation of associated depletion in DO showed that levels would comply with
the WQO at all sensitive receivers for all construction scenarios (see Section 6). Unacceptable impacts to fisheries from
the reduction of DO concentration are not expected to occur.
Nutrients: High levels of nutrients in seawater can cause rapid
increases in phytoplankton, on occasions to the point where an algal bloom
occurs. An intense bloom of algae
can lead to sharp decreases in the levels of dissolved oxygen. This decrease will initially occur in
the surface water, and then deepen 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 mortality to
fish.
The assessment of potential increases in
nutrient levels resulting from construction activities is discussed in Section 6. The results show that increases are
predicted to be very small with maximum increases in Total Inorganic Nitrogen
(TIN) calculated as being 0.0031 mg L-1 and unionised nitrogen (NH3-N)
calculated as being 0.01885 mg L-1. The increased levels of nutrients in the
water column as a result of works are considered to be of negligible
significance for fisheries.
Contaminant Release:
Another potential impact on fisheries resources associated with
disturbance of bottom sediment is the release of potential toxic
contaminants. The potential for
release of contaminants from dredged sediments has been assessed in Section 6, whereas, a comprehensive set
of data on the quality of marine sediment is provided in Section 7. Elutriate
tests that have been carried out in the area of grab dredging show that
dissolved metal concentrations for all samples are below the reporting
limits. The results also show that
all PAHs and PCBs and chlorinated pesticides are all
below the reporting limits. This
indicates that the leaching of these pollutants is unlikely to occur. Impacts on fisheries resources due to
bioaccumulation of released contaminants from dredged sediments are therefore
not expected to occur.
Underwater sound: Intermittent sounds, which occur during activities
such as piling, dredging, jetting and marine vessel movement, may have an
impact on fish during the construction phase. The level of impact is dependent upon
background noise, number of fish present, type of species affected, attenuation
properties of seabed sediments etc.
Percussive piling activity is likely to create the greatest amount of
underwater sound of the proposed marine construction works that are being
considered for this Project.
The area around the wind farm site has been
identified as being subject to relatively high levels of shrimp trawling
activity. In general, there is
little information on the effects of underwater sound on marine invertebrates. However, shrimp do not possess air
filled spaces. They therefore can
only perceive sound as a physical force through external senses. It is therefore 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.
The impact of underwater sound generation from
construction activities on fish is highly dependent upon the hearing
capabilities of the different species present in the area, with the hearing
specialists being of greatest concern.
Effects of increased underwater sound could include physiological
stress, avoidance and injury (at high pressure levels). The significance of these effects is
dependent upon the proximity of fish to the sound source. The potential for injury can be avoided
by adopting appropriate mitigation to promote movement away from the area where
works are being undertaken before any injury can occur. Such mitigation, would include for
example, soft-start or ramp-up approaches for piling activity (slowly
increasing the energy of the emitted sound) (see Section 10.7).
The proposed works are a significant distance from
any FCZs so effects in these areas are likely to be
very small. The proposed offshore
wind farm is also located in open waters and is not in area that is thought to
be unique or important habitat for fish in
Species that are most sensitive to the generation of
sound are likely to instinctively avoid the area once works commence. If avoidance of the area by fish were to
occur during works, it is likely that fish would be temporarily displaced to
other local areas where similar habitat conditions are present. Impacts will also be very short term in
nature with pulses of underwater sound followed by quick returns to be
background levels.
Mitigation measures to reduce potential for impacts
from underwater sound include the adoption of soft start to promote avoidance
of the area in proximity to piling activities. Through these measures impacts on fish
are considered to be of minor significance.
The potential impacts of the Operational Phase of the
Project on the fisheries of the Study Area and the sensitive receivers can be
divided into six main categories:
·
Permanent
loss of fisheries habitat;
·
Long
term changes in benthic habitat;
·
Changes
in fishing pressure;
·
Impacts
associated with the presence of cables and structures; and
·
Underwater
sound impacts associated with operational turbines.
Loss of Fisheries Habitat
It is expected that the direct impacts to fisheries resources
and fishing operations include the permanent loss of 0.16 ha of habitat. This represents 0.0001% of
The seabed at the wind farm site is common to
As discussed in Section
5, an operational safety zone of 50 m radius will be in force from the
substation, turbine and monitoring mast.
This will apply to non-Project vessels throughout the operational period
regardless of other exclusion arrangements. However, the exclusion of fishing
activities within the wind farm area (see below) means that this will lead to no
additional impact for fisheries.
As is common with offshore wind farms, no fishing
activity will be allowed within the wind turbine array or within 500 m of any
turbine, offshore substation or offshore monitoring mast ([8]) ([9]) ([10]).
The overall area lost for fishing activity will, therefore, be
approximately 700 ha, which represents 0.42% of
Long Term Changes in Benthic Habitat
The existing seabed comprises soft muddy sediments
(see Section 7). The wind turbine support structures and
scour protection (if used) will provide hard substrate habitat in the wind farm
area.
These structures could be colonised by a variety of
marine organisms. There is
considerable knowledge in
Colonisation of these structures could provide long
term benefits associated with the attraction of fish and marine invertebrates
(including shrimp) into the area.
This could offset the loss of habitat discussed above. Indeed, this ‘artificial reef’ effect
could lead to enhanced fishery resource in this area due to the aggregation of
reef fish and attraction of other species into the area. It is also possible that production may
increase in the area rather than just an aggregation of existing biomass. The increased number of fish attracted
into the area could be of moderate significance for fishery activities adjacent
to the wind farm site.
Changes in Fishing Pressure
The reduction in fishing pressure within the turbine
array may have a positive impact for commercially exploited stocks and allow
for the attraction of larger fish into the area. In particular, losses to juvenile fish
will be reduced providing improved fishery resources within and adjacent to the
wind farm area. This could have a
beneficial impact of moderate significance for fisheries.
Presence of Cables and Structures
The wind farm structures could present increased risk
of collision for fishing vessels compared to the existing situation. However, the spacing of turbines, size
of fishing vessels and inclusion of appropriate navigation lighting will mean
that risks are low (see Section 10.7). It is concluded that the impact of the
turbines structures on hydrodynamic processes is low and very localised (see Section 6) and these changes will not
affect fisheries.
The restriction of fishing activities in the wind
farm area will mean that there will be no additional concern for fishing
operations associated with cables and/or the placement of scour material.
With the adoption of appropriate marking and lighting
and, adoption of mitigation set out in Section
10.7, impacts are considered to be of negligible significance.
As wind turbines rotate, vibrations travel
down the wind turbine tower and are transmitted into the surrounding water and
seabed. The sound generated
increases with rotational spin as wind speed increases, but this is likely to
be offset by increased natural sources of sound associated with waves etc. The sounds from turbines in operating
wind farms tend to be of low frequency and low level. Estimates of sound levels from 3 MW wind
turbine units are in the order of 110 dB and will therefore likely be absorbed
by background sound. Of note, this
is lower than that generated by marine vessels in the area (see above) ([12]). Underwater sound generated from the wind
monitoring mast during operation will be negligible.
It is unlikely that fish will show an
avoidance reaction to operational sounds.
Monitoring of offshore wind farms and areas around other marine
structures with ‘noisy’ activities, e.g. oil and gas platforms, show the
aggregation of fish during their operation. This shows that fish will habituate to a
low level of underwater sound in a short space of time.
10.6
Assessment of Environmental Impacts
From the information presented above, the
fisheries impact associated with the Project is not considered to be
significant and is considered to be in compliance with Annex 9 of the EIAO-TM as
presented below.
·
Nature of Impact: The nature of potential environmental
impacts has been summarised above in Section
10.5.
·
Size of Affected Area: The wind farm development will lead to a maximum loss
of 0.16 ha of seabed habitat for the foundations installation. Other areas, e.g. those for scour
protection, will be reinstated prior to operation. Approximately 700 ha of habitat will be
lost to fishing activity.
·
Loss of Fisheries
Resources/Production: Fisheries resources and production rates
within the Study Area range from medium to high in terms of catch weight and
value, when compared to other areas in
·
Destruction and Disturbance of Nursery and
Spawning Grounds: There are no recorded fish fry catches in
the Project area and the area of marine waters within the wind farm site
represents a small fraction of identified spawning and nursery grounds, when
compared to the majority of
·
Impact on Fishing Activity: Due to the temporary nature of the construction
activities and the small area of affected seabed, the adverse impacts on
fishing activities arising from construction are expected to be of minor
significance. During operation
phase, the loss of approximately 700ha of habitat available for fishing may
affect local fishermen, specifically those who habitually fish in the project
area. Nevertheless, the potential
for increased fish production and aggregation through the provision of new hard
substratum and protected waters within in the wind farm area during the operational
phase may lead to overall benefits for fisheries.
·
Impact on Aquaculture Activity: No impact has been identified as fish culture zones
are too remote to be affected by the works.
In view of the scale of impacts affected no
significant impacts are expected to be associated with the construction or
operation of the proposed offshore wind farm.
10.7.1
General Measures
In accordance with the guidelines in the EIAO-TM on fisheries impact assessment,
the policy adopted in this EIA for mitigating impacts to fisheries, are:
·
Avoidance: Potential
impacts should be avoided to the maximum extent practicable by adopting
suitable alternatives;
·
Minimisation:
Unavoidable impacts should be minimised by taking appropriate and
practicable measures such as confining works in specific area or season,
restoration (and possibly enhancement) of disturbed fisheries resources and
habitats;
·
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.
The main works have been designed to control water
quality impacts to within acceptable levels and are hence are expected to
control and minimise impacts to fisheries resources. Risks during the construction phase will
be minimised by adopting the following measures:
·
The
use of competent and experienced contractors and vessels operators;
·
Good
planning of the installation sequence to avoid possible clashes;
·
Good
promulgation of information relating to construction activities;
·
Thorough
auditing of all vessels;
·
Observing
good industry construction practices by the Contractors; and,
·
Surveying
of the ‘as-laid’ cable positions and having good quality position
fixing/surveying systems available;
Other
best practice measures that will be adopted for the development of the offshore
wind farm will include informing fishermen of possible developments in
advance.
Specific
measures that relate to navigation risks are discussed below for the
construction and operational phases.
10.7.2
Underwater Sound Measures
As
stated above, piling activities are of greatest concern for the generation of
underwater sound. A number of
mitigation measures are therefore proposed to control and reduce the amount of
underwater sound generated by the works.
These measures are listed below:
·
Using
good engineering practice, including the use of appropriately sized piles
(smaller piles generate lower levels of underwater sound) and piling equipment;
and
·
Using ramp-up piling procedures. This comprises of low energy driving for
a period of time prior to commencement of full piling. This will promote avoidance of the area
by fish when sounds levels are not injurious. Blow frequency during this ramping up
period should replicate the intensity that would be undertaken during full
piling (e.g. one blow every two seconds) to provide cues for fish to localize
the sound source. Pile blow energy
should be ramped up gradually over the ‘soft start’ period.
10.7.3
Vessel Navigation Measures
As
discussed in Section 10.5 the
presence of wind turbine, offshore substation and offshore monitoring mast structures
presents a navigation risk to fishing vessels, particularly as passage will be
allowed for non-fishing vessels. In
order to ensure that risks are acceptable, a range of key mitigation measures
have been identified. Although
these mitigation measures apply to the assessment of impacts on fishing vessels
as required by the Study Brief, these
measures will also mitigate impacts on other types of vessel.
Construction
Phase
Position and Layout of
the Offshore Wind Farm
The
site selection process discussed in Section
3 has ensured that the proposed offshore wind farm development area is
located in an area of relatively low risk for navigation. This has been confirmed by the results
of field survey. In addition, a
geometric layout design has been adopted, which eases navigation between
structures and reduces collision risk in times of low visibility.
Existing Safety
Procedures
Marine
traffic in
Notification, Communications,
Site Protection and Marking
It
is considered that the most effective measures to reduce the potential risk to
fishing vessels is the adoption of appropriate notification, communications,
site protection and marking.
The
relevant authorities will be notified of activities in the wind farm area
during construction activities, including dates of any works. In addition, the Marine Department will
be notified of the final location of the wind farm structures so that these can
be updated on marine charts. All
vessels engaged in construction activities will be equipped with a Maritime VHF
radio and an agreed frequency channel maintained.
Consideration
will also be given to the use of a Guard Ship during the construction phase,
particularly in periods of high activity.
A
safety / exclusion zone of 500 m from any area of construction works will be
established for all non-Project vessels.
The working area will be marked in accordance with Marine Department
Notice No. 23 (2009). All vessels
involved in the construction works will show the correct lights and shapes and
ensure that all movements are promulgated through the Marine Department. In addition, there will be temporary
lighting of incomplete structures (see discussion of lighting and marking under
operational mitigation measures below).
Operational
Phase
The
wind farm will be marked according to the requirements of the Marine
Department. It is expected that the
precise marking arrangement will be agreed during the Detailed Design Phase. However, as set out in Section 5, the corner turbines will have
yellow flashing Morse ‘U’ code lights (5 second interval) visible for 5
nautical miles (9.3 km), located at least +12 mPD
with radar reflectors situated beside them. The intermediate (mid-way) lights will
flash at 2.5 seconds and will be visible for 2 nautical miles (3.7 km).
The
above markings will need to be maintained at all times and should failure
occur, the Marine Department should be notified immediately and repairs
undertaken as soon as possible.
Any
changes to the site will be notified to the Marine Department for alteration to
marine charts and/or notices to mariners.
In
addition, to the above, as stated in Section
5, a 50 m safety zone will be adopted around each structure for non-project
vessels.
10.8
Fisheries
Enhancement Plan
For
the assessment in this EIA, it has been assumed that all fishing activities
will be excluded from inside the development area of the wind farm, including a
500m and 50m buffer around each turbine during construction and operation
phases, respectively. Whilst the
implementation of such safety zones follow standard international practice for
wind farms, it is also noted that the need for the zone should be reviewed as
part of ongoing fisheries management measures to determine whether it is
advisable (from an environmental and marine safety perspective) within the
lifetime of the wind farm to re-introduce specific fishing practices, or
otherwise develop the area further to enhance fisheries resources.
To
this end, a review of Fisheries Review and Consultation Programme (FRCP) will
be implemented no later than the commencement of the installation of the wind
turbines. The general intention of
the FRCP will be to outline, in consultation with the fishery sector, whether
there is scope for fishing operations to be conducted within the development
area. A secondary objective of the
FCRP will be to explore the possibilities of additional measures/projects to be
undertaken within the development area for the enhancement of fisheries
resources.
If
deemed acceptable, a Fisheries Enhancement Plan (FNP) will be developed for the
wind farm area. It is envisaged the
FNP may follow the Food and Agriculture Organisation of the United
Nations ([13]) definition for responsible fisheries
management, which should be an:
“…
integrated process of information gathering, analysis, planning, consultation,
decision-making, allocation of resources and formulation and implementation,
with enforcement as necessary, of regulations or rules which govern fisheries
activities in order to ensure the continued productivity of the resources and
accomplishment of other fisheries objectives.”
Based
on the above objective for the FNP, general goals that could be considered for
the
1.
To
set up objectives for fisheries within and in proximity to the proposed site,
potentially taking into account the known biological characteristics of the
resources, the nature of existing or potential fisheries and other activities
related to or impacting the resources and the potential economic and social
contribution of the fishery to local needs and goals within Hong Kong;
2.
To
determine and implement potential actions necessary to enable HK Electric, the
local fishermen and other interest groups, to work towards the identified
objectives. This task could be done
in consultation with necessary interest groups. Actions could include those working
towards a goal that the resources, the ecosystems in which they occur and their
environment are maintained in a productive state no less than they were prior
to works. Subsequently, where
possible, considerations could also
include the development of fisheries enhancement programme such as deployment
of artificial reefs;
3.
To
have an FNP that is adaptable to changing circumstances (in the surrounding
environment / fishery). In
consultation with stakeholders, including the fishery sector and AFCD, review
the management objectives and measures to verify that they are still
appropriate and effective.
4.
To
report to stakeholders on the state of resources and management performance.
It is
noted that the above goals and objectives are considered to be preliminary and
conceptual in nature and will be reviewed further during the development of the
FNP.
It is
also considered that several entities may likely be integral to achieving
the goals of the FNP. It is
possible that such parties may include Hongkong
Electric, fisheries specialists, the fishery sector / NGOs and AFCD.
10.9
Environmental Monitoring and Audit (EM&A)
As
no unacceptable impacts have been predicted to occur during the construction of
the wind farm, monitoring of fisheries resources during the construction phase
is not considered necessary. There will
be a need to ensure that the seabed affected by the cable installation works
has restored to its original configuration to prevent impacts from occurring to
fishing operations.
As
no unacceptable impacts have been predicted to occur during the operation of
the windfarm, monitoring of fisheries resources
during the operation phase may be designed as part of the FNP to be
developed. Nevertheless, as part of
the FCRP, it is recommended that the need for fisheries resources monitoring
will be consulted with relevant stakeholders and will be confirmed.
10.10
Residual
Environmental Impacts
The
identified residual impact occurring during the construction phase is the
permanent loss of a maximum of 0.16 ha of seabed. In addition, 700 ha of fishing area will
be lost to fisheries activity during the operation of the wind farm. The adoption of appropriate mitigation
measures to manage navigational risks will also mean that the risk to fishing
vessels would be low. The offshore marine structures and scour protection would
provide long term benefits with respect to the creation of an ‘artificial
reef’. The reduced fishing pressure
could also lead to a long term increased fisheries resources within and
adjacent to the wind farm area. On
this basis, it is considered that the construction and operation of the wind
farm would not result in negative but potentially positive residual impacts to
fisheries.
The identified potential concurrent projects that
could lead to cumulative water quality impacts are the marine dumping
activities at the South Cheung Chau uncontaminated
mud disposal site. The key
cumulative impacts associated with mud disposal and activities being proposed
for this Project would be related to construction impacts on water
quality. As discussed in Section 6,
it anticipated that the works proposed for this Project would not lead to
potential for increasing the loading of sediments within the wider marine
environment that is associated with the uncontaminated mud disposal
ground. No significant cumulative
impacts associated with water quality are therefore expected.
A review of existing information on commercial
fisheries resources and fishing operations surrounding the waters adjacent to
the proposed wind farm and cable route has been undertaken. Information from a study on fishing
operations in
Potential impacts to fisheries resources and fishing
operations will arise from the permanent loss of a maximum of 0.16 ha muddy
seabed habitat due to installation of foundations. In addition, there will be approximately
700 ha of fishing grounds lost due to the exclusion of fishing vessels from the
wind farm area. This area encloses
the area of seabed habitat that will be lost in the footprint of wind farm
structures. No unacceptable impacts
associated with the loss of fisheries habitat and fishing ground during
construction and operation of the wind farm is expected to be anticipated.
Impacts arising from the proposed jetting/dredging
and foundation construction works are predicted to be largely confined to the
specific works areas and the predicted adverse impacts to water quality are
expected to be low and transient.
In addition, impacts associated with underwater sounds and vessel
collision risks during construction are expected to be low.
Significant
operational phase impacts to fisheries resources and fishing operations are not
expected to occur. The main works
have been designed to control water quality impacts to within acceptable levels
and are hence are expected to control and minimise impacts to fisheries
resources. Other measures that will
be adopted for the development of the offshore wind farm will include informing
fishermen of possible developments in advance, good engineering practices with
regard to the piling activities and measures for navigation such as a geometric
design of the wind farm, application of Marine Department safety procedures,
notification, communication, site protection and marking, and a safety /
exclusion zone during both construction and operation. The adoption of appropriate mitigation
measures to manage navigational risks will also mean that the risk to fishing
vessels would be low.
Measures
also include the implementation of a Fisheries Review and Consultation
Programme (FRCP). The general
intention of the FRCP will be to outline, in consultation with the fishery
sector, whether there is scope for fishing operations to be conducted within
the development area. A secondary
objective of the FCRP will be to explore the possibilities of additional
measures/projects to be undertaken within the development area for the
enhancement of fisheries resources.
Depending on the outcome of the FRCP, a Fisheries Enhancement Plan (FNP)
may be developed for the wind farm area.