Contents
1.1 Background
1.2 Coral Translocation for Northern Landfall
1.3 Environmental Requirements for Coral Translocation
1.4 Purpose of this Report
2.1 Pre-Construction Survey at the Donor Site
2.2 Pre-construction Survey at the Receptor Site (Tai Mo
TO)
2.3 Alternative Coral Receptor Site
3 rEQUIREMENT OF PRE-TRANSLOCATION CORAL SURVEY
3.1 Pre-Translocation and Translocation Surveys at the Donor Site
3.2 Pre-Translocation
Survey at the Receptor Site
4.1 Coral Translocation Procedures
4.2 Precautionary Measures of Coral Translocation
5 Post-translocation
coral monitoring
5.1 Monitoring Methodology
6 Schedule and Reporting of
Coral Transloation
6.1 Tentative
Schedule
6.2 Reporting
According to
the findings of the Northwest New Territories (NWNT) Traffic and Infrastructure
Review conducted by the Transport Department,
An
Environmental Impact Assessment (EIA) of TM-CLKL was prepared in accordance
with the EIA Study Brief (No. ESB-175/2007) and the Technical Memorandum of the Environmental
Impact Assessment Process (EIAO-TM). The EIA Report was submitted under the
Environmental Impact Assessment Ordinance (EIAO) in August 2009. Subsequent to the approval of the EIA
Report (EIAO Register Number AEIAR-145/2009), an Environmental Permit
(EP-354/2009) for TM-CLKL was granted by the Director of Environmental Protection
(DEP) on 4 November 2009, and EP variation (EP-354/2009A) was issued on 8
December 2010.
Under
Contract No. HY/2012/08,
Dragages ¡V Bouygues Joint Venture (DBJV) is
commissioned by the Highways Department (HyD) to
undertake the design and construction of the Northern Connection Sub-sea Tunnel
Section of TM-CLKL (¡§the Contract¡¨).
ERM-Hong Kong, Limited (ERM) has been appointed as the Environmental
Team (ET) for the Contract.
Table 2.1 Species,
Coverage and Size of Corals Found at Spot-Check Dive Sites at Pillar Point
Site |
Coral Species |
Coverage (%) |
Size in Height/
Diameter (cm) |
PP01 |
Balanophyllia sp. |
<1% |
0.5-1 |
Guaiagorgia sp. |
<1% |
0.1-0.3 |
|
PP02 |
Oulastrea
crispata |
<5% |
5-20 |
|
Balanophyllia sp. |
<1% |
0.5-1 |
|
Guaiagorgia sp. |
<5% |
5-30 |
PP03 |
Balanophyllia sp. |
<1% |
0.5-1 |
Guaiagorgia sp. |
<1% |
10-30 |
Table 2.2 Ecological
and Substratum Attributes of the REA Transects at Pillar Point
Ecological Attributes |
REA 1 (1) |
REA 2 (1) |
Hard
Coral |
1 |
1 |
Dead
Coral |
0 |
0 |
Octocoral (Soft Corals and Gorgonians) |
1 |
1 |
Anemone
Beds |
0 |
0 |
Dead
Standing Corals |
0 |
0 |
Other
Benthos (sponges, zoanthids, ascidians and
bryozoans) |
1 |
1 |
Macroalgae |
0 |
0 |
Substratum Attributes |
REA 1 (1) |
REA 2 (1) |
Bedrock/
Continuous Pavement |
0 |
0 |
Boulders
Blocks (diam. >50cm) |
6 |
5 |
Boulders
Blocks (diam. <50cm) |
2 |
3 |
Rubble |
0 |
0 |
Other |
0 |
0 |
Sand |
0 |
2 |
Mud/Silt |
0 |
0 |
Mud |
0 |
0 |
Note: (1) Rank
of percentage cover: 0 = None recorded; 1 = 1-5%; 2 =
6-10%; 3 = 11-30%; 4 = 31-50%; 5 = 51-75%; 6 = 76-100%
Table 2.3 Ranks
of Taxon Abundance of the REA Transects at Pillar Point
Benthic Taxon |
REA 1 (1) |
REA 2 (1) |
Balanophyllia sp. |
2 |
2 |
Oulastrea
crispata |
3 |
3 |
Guaiagorgia sp. |
3 |
3 |
Sponges |
3 |
3 |
Bryozoans |
3 |
3 |
Saccostrea
cucullata |
3 |
3 |
Perna
viridis |
2 |
2 |
Note:
(1)
Ordinal
Ranks of Taxon Abundance: 0 = Absent; 1 = Sparse; 2 = Uncommon; 3 = Common; 4
= Abundant; 5 = Dominant |
Table 2.4 Species,
Coverage and Size of Corals found at Spot-Check Dive Sites at Tai Mo To
Site |
Coral Species |
Coverage (%) |
Size in Height/
Diameter (cm) |
TMT01 |
Balanophyllia sp. |
<1% |
<1 |
Guaiagorgia sp. |
<1% |
10-25 |
|
TMT02 |
Balanophyllia sp. |
<1% |
<1 |
Guaiagorgia sp. |
<1% |
10-25 |
Table 2.5 Ecological
and Substratum Attributes of the REA Transects at Tai Mo To
Ecological Attributes |
REA 1 (1) |
Hard
Coral |
1 |
Dead
Coral |
0 |
Octocoral (Soft Corals and Gorgonians) |
1 |
Anemone
Beds |
0 |
Dead
Standing Corals |
0 |
Other
Benthos (sponges, zoanthids, ascidians and
bryozoans) |
1 |
Macroalgae |
0 |
Substratum Attributes |
REA 1 (1) |
Bedrock/
Continuous Pavement |
2 |
Boulders
Blocks (diam. >50cm) |
4 |
Boulders
Blocks (diam. <50cm) |
3 |
Rubble |
0 |
Other |
0 |
Sand |
2 |
Mud/Silt |
0 |
Mud |
0 |
Note: (1) Rank
of percentage cover: 0 = None recorded; 1 = 1-5%; 2 =
6-10%; 3 = 11-30%; 4 = 31-50%; 5 = 51-75%; 6 = 76-100%
Table 2.6 Ranks
of Taxon Abundance of the REA Transects at Tai Mo To
Benthic Taxon |
REA 1 (1) |
Balanophyllia sp. |
2 |
Guaiagorgia sp. |
2 |
Sponges |
3 |
Bryozoans |
3 |
Saccostrea
cucullata |
3 |
Perna
viridis |
2 |
Sabellastarte
japonica |
2 |
Note:
(1)
Ordinal
Ranks of Taxon Abundance: 0 = Absent; 1 = Sparse; 2 = Uncommon; 3 = Common; 4
= Abundant; 5 = Dominant |
l
According
to overseas experience of gorgonian translocation, growing edge of the holdfast
will recede or die back when the detached gorgonian is being glued to the
substrate of the receptor site by epoxy or underwater cement ([1]);
l
Under
relatively strong current, it is unlikely to be able to attach the gorgonian
firmly to the substrate and high mortality is thus expected for the translocated gorgonian; and
l
The
colony of Guaiagorgia sp. does not exhibit an obvious
central spine (please refer to Appendix B for photos of Guaiagorgia
sp.) and it would be difficult to glue the detached gorgonian to the substrate,
leading to easy detachment by current and consequently high mortality.
It is
preferable to a select receptor site with the following characteristics:
l
In
the vicinity of the original coral colony;
l
Not
impacted by the Project or other construction/ activities;
l
Presence
of healthy coral community of the same species and similar hydrographical
conditions as donor site; and
l
With
sufficient space to receive the newly translocated
coral colonies.
As mentioned
in the previous section, Tai Mo To is not a suitable
receptor site due to the exposed and rough sea conditions, and the absence of Oulastrea crispata.
Recent coral surveys for another project (Contract No. HY/2011/03: Hong Kong-Zhuhai-Macao Bridge - Hong Kong Link
Road) showed that the coastline of Yam Tsai Wan is an optional coral
receptor site for translocation as it shares similar habitat to the existing
corals to be translocated (Figure 2.5).
A
pre-translocation survey will be conducted at the proposed receptor site at Yam
Tsai Wan to ensure its suitability before the translocation of corals commenced
at the donor site of Pillar Point.
A spot-check dive will be conducted at the proposed receptor site and
its vicinity to check for the presence of healthy coral colonies such as hard
coral Oulastrea
crispata and gorgonian Guaiagorgia sp. which had been
observed in previous surveys.
Following the
spot-check dive, the substrate type and taxonomic composition of the receptor
site will be assessed using REA method.
The REA survey will be performed along a 100 m transect parallel to the
coastline (based on the preliminary results from the spot-check dives). The substrate type along the length of the transects will be recorded at 1 m intervals. The benthic cover, taxon abundance, and
ecological attributes along the transects will also be
recorded in a swathe of 2 m wide, 1 m either side of the transect.
The locations
of the REA transects will be recorded on-site using a handheld GPS unit. The number of colonies, sizes and types
of corals, their coverage, abundance, depth, health status of coral species
will also be recorded. Photographs
of representative taxa along the transects will also
be taken during the surveys.
Health status
of coral will be assessed by the following criteria:
l
Gorgonian
coral: Percentage of branches
exhibiting partial mortality and secretion of mucus.
l
Hard
coral: Percentage of surface area
exhibiting partial mortality and blanched/ bleached area using specially
designed Coral Health Monitoring Chart (Appendix
C).
Table 3.1 Tier
I Benthic Attribute Categories
Ecological Attributes |
Substratum Attributes |
Hard
Coral |
Hard Substrata |
Dead
Coral |
Bedrock/
Continuous Pavement |
Octocoral (Soft Corals and Gorgonians) |
|
Anemone
Beds |
|
Dead
Standing Corals |
Rubble |
Other
Benthos (sponges, zoanthids, ascidians and
bryozoans) |
Other |
Macroalgae |
Soft Substrata |
|
Sand |
|
Mud/Silt |
|
Mud |
Table 3.2 Tier
I Ordinal Ranks of Percentage Cover of Benthic Attributes
Rank |
Percentage Cover |
0 |
None
Recorded |
1 |
1-5% |
2 |
6-10% |
3 |
11-30% |
4 |
31-50% |
5 |
51-75% |
6 |
76-100% |
For substratum
attributes, it is preferable to record actual estimates of cover. The percentage of hard substrata vs.
soft substrata can be provided (e.g. 80% and 20% respectively). The percentage cover of the types of
hard or soft substrata could also then be presented (e.g. bedrock pavement 60%,
rubble 20%, sand 15%, mud / silt 5%).
Similarly, recording and presenting actual estimates of, for instance,
hard and soft coral cover may be more informative (e.g. <1%).
Tier II ¡V
Taxonomic Inventories to Define Types of Benthic Communities
An inventory
of benthic taxa along each transect will be compiled during the survey. Taxa will be identified in situ to the
following levels:
l
Hard
corals to species, where possible;
l
Soft
corals, anemones and conspicuous macroalgae to genus
level, where possible;
l
Other
benthos (including sponges, zoanthids, ascidians and
bryozoans) to genus level, where possible.
For each
transect, each taxon in the inventory will be ranked in terms of abundance in
the community (Table 3.3). The taxon categories will be ranked in
terms of relative abundance of individuals, rather than the contribution to
benthic cover along each transect.
The ranks are visual assessments of abundance, rather than quantitative
counts of each taxon. Representative
photos of organisms will be taken.
Table 3.3 Ordinal Ranks of Taxon
Abundance
Rank |
Relative Abundance |
0 |
Absent
|
1 |
Sparse |
2 |
Uncommon |
3 |
Common |
4 |
Abundant |
5 |
Dominant |
In order to
distinguish the natural variation in health status of corals and the health
variation due to coral translocation, a certain number of natural coral
colonies (eg 10 colonies) of the same species as
those translocated from the donor site within and adjacent
to the receptor site will be randomly selected and tagged. Baseline information will be collected
for these tagged coral colonies before translocation and the type of
information collected will be the same as those collected for the coral colony during
the baseline survey at the donor site.
The baseline information collected will be used for the purpose of
post-translocation monitoring.
Upon
completion of the pre-translocation surveys, the requirement for translocation
and the required dimensions of the receptor site will be identified If necessary, fine tuning / adjustment
to the location of the preferred receptor site for successful translocation
should be considered. Once the
exact location of the receptor site is marked, GPS coordinates will be
recorded.
The
pre-translocation survey should be carried out by a qualified marine
biologist(s) with specialist knowledge of corals and sound experience at
identifying sessile benthic taxa in the field. The qualification of the specialists
proposed for the dive survey will be provided to and approved by AFCD prior to
the pre-translocation survey.
Results of the
baseline surveys at the donar and receptor sites will
be presented in the Detailed Translocation Report to be submitted after
completion of the coral translocation exercise (see Section 6 below).
The following
procedures will be performed during coral translocation to minimize stress and
prevent damage to corals, as far as possible.
l
Since
the underwater visibility at the donor site is very low (<0.5m), relocating
all tagged coral colonies after coral mapping is almost impossible. Therefore, coral translocation will be
undertaken immediately after locating the movable coral colonies.
l
All
tagged movable boulder (with diameter <50 cm) supporting coral colony which
is selected for translocation will be moved entirely as a whole object, lifted
from the sea bottom and loaded to ship/boat with lifting bag.
l
The
coral colonies transferred onto the vessel will be fully submerged in seawater
tanks of suitable size with continuous aeration onboard. Each seawater tank will hold no more
than four boulders to avoid overcrowding.
l
Ambient
water quality parameters such as sea surface water temperature and dissolved
oxygen will be measured once (with at least three replicates) at the coral
donor site on the day of coral translocation. The seawater quality in the tanks will be
checked every 10 minutes to ensure no fluctuation above 10% of ambient occurs
to the seawater in which the coral colonies are submerged.
l
Corals
will be transported to the receptor site as soon as possible on the same day
following the removal. The vessel
will progress in a slow and steady speed (<5 knots) when approaching close
to the receptor site.
l
When
arriving at the coral receptor site, SCUBA divers, under the supervision of
marine biologist with relevant experience, will carefully place the boulders
with coral colonies one by one to the seabed in order to minimize disturbance
to the seabed and/or sediment. The
coral colonies will be positioned to similar depths and orientations as their
previous locations at the donor site as far as possible.
l
Divers
will tag translocated colonies at the receptor site
with small plastic labels (e.g. with colony number) anchored or attached on
nearby hard substratum using epoxy without touching the corals. All tags will be anchored in vicinity of
the coral colonies at distances not so close to interfere with the potential
growth. This would allow the
revisit of the coral colonies during the post-translocation monitoring.
l
Divers
will record the size, location, health conditions (percentage of mortality and
bleaching), percentage cover of sediment of each translocated
coral colony after the completion of translocation works using the same
methodologies adopted in the pre-translocation coral survey. Photographs of each translocated
coral upon completion of translocation will be taken and used as a baseline for
future monitoring.
The following
precautionary measures will be adopted during the coral translocation process:
l
In
the case where any tagged boulder with corals recorded during the
pre-translocation survey no longer accommodates live coral growth, the boulder
will not be moved. If additional
boulders with coral that can be moved are discovered, these boulders will also
be incorporated into the translocation works.
l
Effort
will be made to minimize the amount of contact by the diver and the length of
time the boulders/rocks are handled.
All the coral colonies attached on the boulders will be kept submerged
at all times with a brief unavoidable exposure when transferred onto the
vessel.
l
The
placement of boulders in tanks will ensure that the coral colonies are fully
covered by seawater. Coral exposure
to air should be avoided as far as possible during the translocation process
from the donor site to the receptor site.
Shading will also be provided by placing the seawater tanks under roof
of the vessel to avoid exposure to direct sunlight.
l
Constant
supervision of the boulders and the correct orientation of the boulders in the
seawater holding tanks will be carried out to ensure coral colonies are not
being stressed or damaged on the way to the receptor site.
l
The
coral translocation should be carried out by a qualified marine biologist(s)
with specialist knowledge of corals and sound experience in coral
identification and translocation works.
The qualification of the specialists proposed for the dive survey shall
be provided to and approved by AFCD prior to the coral translocation.
After translocation
is complete, an audit survey will be carried out to determine if all corals
have been moved. The audit survey
may be undertaken on the same day of completion of the coral translocations
works or after that. Following the
audit survey, the translocated coral colonies as well
as the tagged natural coral colonies at the receptor site will be monitored
once every three (3) months for a period of 12 months. The size, survival, health conditions
(percentage of mortality / bleaching) and percentage cover of sediment of each translocated coral colony will be recorded during the
monitoring, using the same methodology adopted during the pre-translocation
survey. The general environmental
conditions including weather, sea and tidal conditions of the coral receptor
site will also be monitored. A
sample of survey record form is provided in Appendix
D.
Photographic
records of the translocated and natural coral
colonies will be taken as far as possible maintaining the same aspect and
orientation as photographs taken for the pre-translocation surveys. All the tags for marking the translocated and natural coral colonies will be removed /
retrieved once the monitoring programme is completed.
The results of
the post-translocation monitoring should be reviewed with reference to findings
of the pre-translocation survey and the data from original colonies at the
receptor site.
If
observations of any die-off / abnormal conditions of the translocated
corals are made during the post-translocation monitoring, the ET should inform
the Contractor, Independent Environmental Checker (IEC) / Environmental Project
Office (ENPO), and AFCD, and liaise with AFCD to investigate any mitigation
measures needed.
Post-translocation
monitoring results will be evaluated against Action and Limit Levels. Evaluation will be based on recorded
changes in percentage of partial mortality of the corals. Action and Limit Levels are defined in Table 5.1.
Table 5.1 Action
and Limit Levels for Post-Translocation Coral Monitoring
Parameter |
Action Level Definition |
Limit Level Definition |
Mortality |
If during
Impact Monitoring a 15% increase in the percentage of partial mortality on
the corals occurs at more than 20% of the translocated
coral colonies that is not recorded on the original corals at the receptor
site, then the Action Level is exceeded. |
If during
Impact Monitoring a 25% increase in the percentage of partial mortality on the
corals occurs at more than 20% of the translocated
coral colonies that is not recorded on the original corals at the receptor
site, then the Limit Level is exceeded. |
Table 5.2 Event
and Action Plan for Post-Translocation Monitoring
Event |
Action |
|||
ET Leader |
IEC |
SOR |
Contractor |
|
Action
Level Exceedance |
1.
Check monitoring data 2.
Inform the IEC, SOR and
Contractor of the findings; 3.
Increase the monitoring to at
least once a month to confirm findings; 4. Propose mitigation measures for consideration |
1.
Discuss monitoring with the ET and
the Contractor; 2.
Review proposals for additional
monitoring and any other measures submitted by the Contractor and advise the
SOR accordingly. |
1.
Discuss with the IEC additional
monitoring requirements and any other measures proposed by the ET; 2.
Make agreement on the measures to
be implemented. |
1.
Inform the SOR and confirm
notification of the non-compliance in writing; 2.
Discuss with the ET and the IEC
and propose measures to the IEC and the SOR; 3.
Implement the agreed measures. |
Limit
Level Exceedance |
1. Undertake Steps 1-4 as in the Action Level Exceedance. If further exceedance
of Limit Level, propose enhancement measures for consideration. |
1.
Discuss monitoring with the ET
and the Contractor; 2.
Review proposals for additional monitoring
and any other measures submitted by the Contractor and advise the SOR
accordingly. |
1.
Discuss with the IEC additional
monitoring requirements and any other measures proposed by the ET; 2.
Make agreement on the measures to
be implemented. |
1.
Inform the SOR and confirm
notification of the non-compliance in writing; 2.
Discuss with the ET and the IEC
and propose measures to the IEC and the SOR; 3.
Implement the agreed measures. |
Following
approval of this Detailed Coral Translocation Methodology, the
pre-translocation coral surveys will be undertaken at the receptor site of Yam
Tsai Wan in October 2013. The receptor
site survey will be followed by the pre-translocation survey and coral
translocation at the donar site of Pillar Point which
will be undertaken at the same time.
Following completion of the coral translocation, an audit survey will be
undertaken on the same day of completion of coral translocation or after
that. It is expected that the
pre-translocation coral surveys, coral translocation and audit survey will be
completed by October 2013 and a tentative schedule is presented in Table 6.1 below.
Table 6.1 Tentative Schedule of
Pre-Translocation Coral Surveys, Coral Translocation Works and Audit Survey
Day |
Task |
Day
1 |
Pre-translocation
survey at the receptor site Yam Tsai Wan. |
Day
2 |
Coral
mapping at Pillar Point; Coral
translocation from Pillar Point to Yam Tsai Wan. |
Day 3 |
Coral
mapping at Pillar Point; Coral
translocation from Pillar Point to Yam Tsai Wan. |
Day 4 |
Coral
mapping at Pillar Point; Coral
translocation from Pillar Point to Yam Tsai Wan. |
Day 5 |
Coral
mapping at Pillar Point; Coral
translocation from Pillar Point to Yam Tsai Wan. |
Day 6 |
Coral
mapping at Pillar Point; Coral
translocation from Pillar Point to Yam Tsai Wan. |
Day 7 |
Audit
survey to confirm that all target coral colonies for translocation have been
removed from Pillar Point |
The tentative
schedule of the quarterly post-translocation monitoring is provided in Table 6.2 below.
Table 6.2 Schedule of Quarterly
Post-Translocation Monitoring
Post-Translocation
Monitoring Survey |
Timing |
1st
Quarterly Monitoring |
3
months after the translocation works |
2nd
Quarterly Monitoring |
6
months after the translocation works |
3rd Quarterly Monitoring |
9
months after the translocation works |
4th Quarterly Monitoring |
12
months after the translocation works |
A Detailed
Translocation Report will be submitted to EPD and AFCD upon the completion of
the translocation works. The
locations, conditions and photographic records of the translocated
corals and the conditions of the receptor site will be detailed in the
report. This report will be
submitted within two weeks from completion of the coral translocation works
which is anticipated to be in late October 2013.
A
Post-Translocation Monitoring Report will be submitted to EPD and AFCD two
weeks after completion of each quarterly survey. The results of the post-translocation
monitoring surveys should be reviewed with reference to the pre-translocation
survey results and findings.