9.1.1
This
section identifies and evaluates the potential impacts on capture and culture
fisheries in the assessment area resulting from proposed dredging works in the
Project. This assessment is based
on desktop review of the latest relevant literatures to describe the baseline
condition, identify and evaluate potential direct, indirect, residual and
cumulative impacts on fisheries resources during the proposed dredging
works. Mitigation measures and
monitoring programme would be recommended, if necessary.
9.2
Environmental Legislation, Standards and
Guidelines
9.2.1
This
fisheries impact assessment is conducted according to criteria and guidelines
set out in the EIAO-TM Annex 9 and Annex
9.2.2
Other
local legislation that applies to fisheries and is relevant to this fisheries
impact assessment includes the following:
l
Fisheries Protection Ordinance (Cap. 171) – aims
to promote the conservation fish and other forms of aquatic life within the
l
Marine Fish Culture Ordinance (Cap. 353) –
regulates and protects marine fish culture by designating areas of fish culture
zone, granting license, prohibiting unauthorized vessels and any deposition of
chemicals or other substance which are likely to cause injury to fish in a fish
culture zone. The list of
designated fish culture zones was last revised in January 2000.
l
The Water Pollution Control Ordinance (Cap.358)
– aims to control water pollution in the waters of
9.3.1
Baseline
fisheries conditions are elucidated via a review of relevant literatures
including the latest fisheries data presented in the AFCD Port Survey Report
2001-2002 and other relevant information available in other reports and
publications listed below. No
necessary field survey is identified and conducted in this assessment.
l
Agreement No. CE 42/2001, Environmental and
Engineering Feasibility Assessment Studies in Relation to the Way Forward of
the Harbour Area Treatment Scheme – Water Quality, Ecological and Fisheries
Impact Assessment (HATS EEFS Report).
l
Agreement No. CE 87/2001, Further Development of
Tseung Kwan O – Feasibility Study (TKOFS EIA)
9.3.2
Potential
impacts on capture and culture fisheries resources arising from the Project are
identified and evaluated using the EIAO-TM evaluation criteria listed in Annex
9 and guidelines presented in Annex 17.
Results of the water quality modelling were used to assess the extent
and severity of indirect impacts during the capital and maintenance dredging
works, and in the formulation of mitigation measures, if required.
9.4
Description of the Environment
9.4.1
The
assessment area for the fisheries impact assessment included all areas within
Capture
Fisheries
9.4.2
In
Table 9.1 Recent
Parameter |
2005 |
2004 |
2003 |
2002 |
2001 |
2000 |
Fishing fleet size (No.
of vessels) |
4,150 |
4,300 |
4,600 |
4,470 |
5,100 |
5,250 |
Portion of fishing fleet
comprising sampans (P4) and non-mechanised vessels |
No data |
No data |
No data |
53% |
54% |
51% |
Local fishermen engaged
in capture fisheries |
9,170 |
9,700 |
10,100 |
10,860 |
11,560 |
11,900 |
Mainland deckhand
employed |
No data |
No data |
3,908 |
4,100 |
4,560 |
5,200 |
Production (tonnes) |
162,000 |
167,500 |
157,400 |
169,790 |
174,000 |
157,010 |
Value of produce (HK$
million) |
1,600 |
1,600 |
1,500 |
1,600 |
1,700 |
1,600 |
Note: no data = data were
unavailable at time of reporting
Source: AFCD Annual
Reports, 2000 - 2006
9.4.3
The
latest AFCD Port Survey 2001-2002 provides the most updated and detailed
information on capture fisheries in
Table 9.2 Summaryof
Capture Fisheries Data in Assessment Area by Vessels<
Parameter |
|
Eastern |
KTTS |
TKWTS |
KTAC |
No.
of vessels |
100-400 |
100-400 |
100-400 |
10-50 |
0 |
Adult
fish production in terms of weight (kg/ha) |
100-400 |
100-400 |
200-400 |
>
0 and < = 50 |
0 |
Fish
fry production in terms of weight (kg/ha) |
0 |
0 |
0 |
0 |
0 |
Fisheries
production (adult and fry) in terms of value (HK$ /ha) |
5,000-10,000 |
5,000-10,000 |
5,000-10,000 |
1,000-2,000 |
0 |
Source: AFCD, 2007at (http://www.afcd.gov.hk)
9.4.4
The
latest Port Survey did not record any fishing operation or fisheries production
in the KTAC, showing that this area has no or very limited value in capture
fisheries.
9.4.5
The
scale of fishing activities in terms of number of fishing vessels operating in
the Kowloon Bay, eastern Victoria Harbour and KTTS are considered to be
moderate (100-400 vessels) as compared with other fishing grounds in Hong Kong. In contrast, fisheries operation in the
TKWTS is very limited with only 10-50 vessels recorded.
9.4.6
In
terms of weight, fisheries production for adult fish in the
9.4.7
Important
nursery grounds can be identified from the main areas of fry collection for the
mariculture industry. Fry
collection in
9.4.8
The
most common capture fish in the Assessment Area was Rabbitfish
(Siganidae). Very high production
of over
9.4.9
Other
medium-valued species such as Seabream (Sparidae) and crab produced moderate
yield of about 20
9.4.10
Overall,
in terms of their capture fishery production values, fishing areas in Kowloon
Bay, eastern Victoria Harbour and KTTS are ranked moderate to high value with
production value of HK$5000-10000/ha annually whereas TKWTS produced about
HK$1000-2000/ha every year and is considered as moderate-valued as compared
with other fishing grounds in Hong Kong.
Culture
Fisheries
9.4.11
Culture
fisheries, on the other hand, included 26 fish culture zones (FCZs) located in
various sheltered coastal areas in Hong Kong marine waters and occupied about
9.4.12
Mariculture
areas including marine fish culture and oyster culture were absent in the
Assessment Area. The nearest fish
culture zones (FCZs) identified in the vicinity of the Project area are Tung
Lung Chau FCZ (
9.4.13
Although
no figures are available on the individual production of these FCZs, it was
estimated that culture fisheries production in 2006 was
about 1,488 tonnes valued at $89 million which catered about 7.9 per cent of
local demand for live marine fish. (AFCD, 2007b). Some recent
figures on marine culture fisheries are presented in Table 9.3.
Table 9.3 Recent
Parameter |
2006 |
2005 |
2004 |
2003 |
2002 |
2001 |
2000 |
Licensed operator |
1,080 |
1,100 |
1,125 |
1,155 |
1,237 |
1,320 |
1,418 |
Production (tonnes) |
1,488 |
1,539 |
1,540 |
1,490 |
1,210 |
2,470 |
1,770 |
Value (HK$ million) |
89 |
76 |
79 |
76 |
57 |
136 |
102 |
Source: AFCD Annual Reports,
2000 – 2006 and (AFCD, 2007b)
9.4.14
The
species cultured changed gradually over the recent years depending on the
availability of imported fry.
Common species under culture include green grouper,
brown-spotted grouper, giant grouper,
Russell's snapper, mangrove
snapper, red snapper, star snapper, and pompano
(AFCD, 2007b).
9.5
Identification, Prediction and Evaluation of Environmental Impacts
9.5.1
Impacts
to fisheries resources may occur during the implementation of the Project,
including the capital dredging and the regular maintenance dredging. The impacts may be derived from direct
loss of fishing area or indirect disturbance through changes to key water
quality parameters.
Loss of
fishing grounds
9.5.2
Potential
direct impacts on fisheries resources arising from the Project would include
loss of fishing area in
9.5.3
Although
fisheries importance in Kowloon Bay and eastern Victoria Harbour are considered
as moderate to high in terms of adult fish production and commercial fishing
activities as compared with other fishing locations in Hong Kong, the affected
fisheries area only constitute a very small portion of the total fishing area
in Hong Kong. The loss of fishery
production would be temporary and insignificant as compared with the total
fishery production in
9.5.4
Fishing
activities in the affected area constitutes only a small proportion of total
fishing operations in
9.5.5
The
most common capture fish in the affected area was confined to Rabbitfish which
is of relatively low economic value (FMO 2007). No important nursery or spawning area
was identified within the assessment area (ERM, 1998).
9.5.6
In
view of the small size of the affected area, temporary and insignificant loss
of fisheries production and low impact on fishing activities, such fisheries
impacts due to capital and maintenance dredging are expected to be minor and
acceptable.
Changes in water quality
9.5.7
Potential
indirect impacts to the fisheries resources would include changes in water
quality due to capital and maintenance dredging activities of seabed sediment
and potential site run-off from land-based construction works.
Elevation
of suspended solid (SS)
9.5.8
Dredging
activities would temporarily elevate the suspended sediment level and create
sediment plumes. Possible indirect
impact on fisheries resources may be resulted during the dredging activities. Effects could be lethal or sublethal
through reduction in survivalship, growth rate and reproductive potential due
to stress incurred by the need to constantly flush out deposited material. High SS level may clog gill structure of
fish and cause physical damage and hinder transfer in oxygen. Fish egg and larval fish (fry) are more
susceptible to deleterious impacts from sedimentation through smothering and
clogging of their respiratory systems.
Adult fish is generally less sensitive to effects from suspended
sediments.
9.5.9
Suspended
sediment plume occurs naturally in the marine environment by wave action and
vertical flux of water current.
Fish has evolved behavioural adaptations to sudden turbid water,
including clearing their gills by flushing water or simply avoiding movement to
turbid waters.
9.5.10
Based on the prediction of the sediment plume modelling for the
unmitigated scenarios under the water quality impact assessment (see Section
5), potential water quality impact due to elevation of SS would occur at
coastal waters of the Kowloon Bay.
It is predicted that impacts to fisheries resources immediately outside
of the dredging area would occur because the elevation of SS is predicted to
significantly increase from ambient levels at
several locations (Water Quality Section, Appendix 5.4 to Appendix 5.9). A number
of mitigation measures to control water quality are therefore recommended to
confine sediment plume within the proposed dredging area and to minimize the SS
elevation during dredging operations.
With the implementation of the proposed mitigation measures as suggested
in the water quality impact assessment, the water quality modelling results
indicate that the SS elevation arising from this Project could be effectively
reduced. In view of the
temporary nature of such impact, only minor impact on capture fisheries is
anticipated.
9.5.11
Impact
is not expected to occur at the far field fisheries sensitive receivers such as
Tung Lung Chau FCZ and Ma Wan FCZ as they are located outside the influence
zone of the predicted sediment plumes (Water Quality Section, Appendix 5.4 to Appendix 5.9). Thus, no adverse
impacts on these FCZs would be expected from the proposed dredging works.
Contaminant Release During Dredging
9.5.12
Dredging
activities can potentially cause the release of contaminants from marine mud.
Potential impacts on fisheries resources include the accumulation of
contaminants in the tissues of fish, resulting in sublethal effects which may
alter behaviour, reproduction and increase susceptibility to disease. Eggs, larvae and juveniles are
particularly susceptible to the sublethal effects of contaminants, and elevated
levels may lead to increased mortality. Bioaccumulation in commercially
important fish species may ultimately impact human health.
9.5.13
In-vitro
laboratory assessment of sediment samples indicated that the concentrations of
cadmium, copper, nickel, mercury, unionised ammonia and total inorganic
nitrogen contaminants exceeded the assessment criteria. However the laboratory tests do not take
into account the dilution factor after the contaminants are released. Water quality modelling results predict
that levels of contaminants would be much lower than the relevant standards at
monitoring sites nearby the source.
This is because any contaminants released during dredging are
immediately diluted by the large volume of marine water within the dredging
site. Thus, it is considered that
long-term off-site marine water quality impact is unlikely and any local water
quality impact will be transient (see Water Quality Section 5 para. 5.8.8 – 5.8.18 for more details).
Decrease
of dissolved oxygen (DO)
9.5.14
The
relationship between SS and DO are complex. Increase in SS in water column combining
with a number of other physical or biotic factors would reduce DO in water
column. Elevated SS reduces light penetration, lower the photosynthetic rate of
phytoplankton and so lower the rate of oxygen production in water column. Also, the release of inorganic
substances from the dredged sediments may cause eutrophication and algal bloom. Oxidation of dead algae may use up some
of the oxygen in the water. If
oxygen levels are depleted to low levels, fish, especially those in early life
stages may be unable to tolerate such conditions and suffer hypoxia-induced
mortality and / or stress including reduced feeding and growth rate.
9.5.15
The
WQO standard for the
9.5.16
Maintenance
dredging will be required during operation of the proposed cruise terminal at a
frequency of about once every 5 to 10 years. The approximate time to complete
maintenance would be <6 months for each berth. The maximum dredging rate
during maintenance dredging (
9.6
Mitigation of Environmental Impacts
9.6.1
Following
EIAO-TM Annex 17, mitigation measures are discussed in this section to avoid,
minimize, and compensate for identified fisheries impacts.
9.6.2
The
mitigation measures recommended in the water quality impact assessment to
control water quality would serve also to protect fisheries resources from
indirect impacts and ensure no adverse impact on fisheries resources would
result from the Project. Those measures should also be strictly implemented
during maintenance dredging.
9.7
Evaluation of
Residual Environmental Impacts
9.7.1
The only residual impact would be the temporary loss
of 57 hectares of
fishing area. In view of the small
size of affected area, negligible loss of fisheries production and low impact
on fishing activities, direct loss of fishing area within the dredging area is
considered as minor and acceptable.
9.8
Evaluation of Cumulative Environmental Impacts
9.8.1
There
is a number of construction activities planned for other projects that would be
conducted in and within the vicinity of the Project area such as construction
of
9.8.2
As
dredging and filling activities would be also included in the above projects,
the most concerned cumulative impact would be the cumulative effect on the
deterioration of water quality in the
9.8.3
Cumulative potential impacts on fisheries resources
would be the same as the potential impacts predicted above. However with the implementation of
proper mitigation measures recommended in the water quality impact assessment,
cumulative impact on water quality parameters in the Project area could be
effectively minimized and the associated fisheries impacts are thus expected to
be acceptable.
9.9
Environmental Monitoring and Audit
9.9.1
No
unacceptable fisheries impacts would be expected from the Project. No monitoring programme specific for
fisheries would be required.
9.10.1
Literature
reviews of existing information indicated that identified fishing area in
9.10.2
Direct
and indirect impacts on fisheries resources arising from the Project were
identified and evaluated. The
Project will result in the temporary loss of approximately 57 hectares of
fishing area. In view of the small
size of affected area, temporary and insignificant loss of fisheries production
and low impact on fishing activities, fisheries impacts due to direct loss of
fishing area within the dredging area is considered as minor and
acceptable.
9.10.3
Indirect
impacts of change of water quality arsing from the Project would be temporary
and insignificant based on the predictions from water quality modelling. Mitigation measures suggested in the
water quality impact assessment to control water quality would also serve to
protect fisheries resources from indirect impacts. No significant adverse impact on
fisheries resources would be expected from the Project and therefore no
necessary fisheries-specific mitigation measures would be required.
Agriculture and Fisheries Department. (2003). Port
Survey 2001/2002, Capture Fisheries Division.
Agriculture and Fisheries Department. (
Agriculture and Fisheries Department. (2007b).
Fisheries: Aquacullture. http://www.afcd.gov.hk/
CDM (2004). Environmental and Engineering
Feasibility Assessment Studies in Relation to the Way Forward of the Harbour
Area Treatment Scheme, Working Paper No.3 & 9.
Environmental Resources Management, ERM (1998).
Fisheries resources and fishing operations in
Fish Market Organisation. (2007). Wholesale
Price of Fresh Marine Fish / Live Marine Product on
Maunsell (2005). Agreement No. CE 87/2001 (CE)
Further development on Tseung Kwan O feasibility study EIA final report.