Contents
1.1 Background
1.2 Coral Translocation for Southern Viaduct
1.3 Environmental Requirements
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 Site13
3.2 Pre-Translocation Survey at
the Receptor Site
4.1 Coral Translocation
Procedures
4.2 Precautionary
Measures of Coral Translocation
4.3 Preliminary Coral Translocation Schedule
5 Post-translocation
coral monitoring
5.1 Monitoring Methodology
6 Schedule and Reporting of Coral TransloCation
6.1 Tentative Schedule
6.2 Reporting
1
Introduction
1.1
Background
According
to the findings of the Northwest New Territories (NWNT) Traffic and
Infrastructure Review conducted by the Transport Department, Tuen Mun Road,
Ting Kau Bridge, Lantau Link and North Lantau Highway would be operating beyond
capacity after 2016. This forecast
has been based on the estimated increase in cross boundary traffic,
developments in the Northwest New Territories (NWNT), and possible developments
in North Lantau, including the Airport developments, the Lantau Logistics Park
(LLP) and the Hong Kong – Zhuhai – Macao Bridge (HZMB). In order to cope with the anticipated
traffic demand, two new road sections between NWNT and North Lantau – Tuen Mun
– Chek Lap Kok Link (TM-CLKL) and Tuen Mun Western Bypass (TMWB) are proposed.
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/2012/07, Gammon
Construction Limited is commissioned by the Highways Department (HyD) to
undertake the design and construction of the Southern Connection Viaduct
Section of TM-CLKL (“the Contract”).
ERM-Hong Kong, Limited (ERM) has been appointed as the Environmental
Team (ET) for the Contract.
1.2
Coral Translocation for
Southern Viaduct
According
to the approved EIA Report of the TM-CLKL, due to the fact that no corals were
recorded in the southern reclamation location and that the existing coral
populations on the seawall in the southern landing area at Tai Ho Wan are far
away (>10m) from the proposed reclamation area and from either side of the
viaduct piers, no direct impacts on corals were anticipated in the location of
the southern viaduct landing area.
However, during the design and construction stage of the Southern
Connection Viaduct Section, it became apparent that the water depth in the
vicinity of bridge structures south of the Tung Chung Navigation Channel is too
shallow. This constraint will
prohibit transportation of piling rigs and related plant by flat barges being
towed by tug boats to the piling locations. Therefore, temporary staging platforms
with associated extension from the existing navigation channel/ land would be
required.
The
construction of temporary staging would involve the removal of about 25 m rock armour at each landing position (total 3 landing
positions). According to the coral
survey in the approved EIA, coral communities are identified at certain
locations (for example, survey station C7 as shown in Figure 1.1)
along the seawall of the North Lantau Highway section at Tai Ho Wan. Potential direct impact to the coral
communities at the affected seawall may thus arise. Coral translocation was therefore
recommended for the coral colonies at Tai Ho Wan prior to construction of the
temporary staging platforms in order to reduce the potential marine ecological
impacts.
1.3
Environmental Requirements
According to Condition 2.6 of the EP-354/2009A, the Permit Holder shall submit to the Director
of Environmental Protection (DEP)
for approval, at least one month before the commencement of construction of the
Project, three hard copies and one electronic copy of a detailed coral
translocation methodology, including pre-translocation survey, identification
of receptor site and post-translocation monitoring.
In
addition, according to Section 6.4.3.1 of the EM&A Manual, a pre-construction survey of corals at Tai Ho Wan and
potential receptor site(s) should be conducted prior to the translocation
works. The suitability of the
potential receptor site(s) should be reviewed and verified,
and alternative receptor site(s) be proposed if necessary. A Coral Translocation Proposal, which
includes findings of the pre-construction surveys, should be submitted for
AFCD’s agreement. Coral translocation
should then be undertaken prior to any major relevant construction works in
accordance with the Detailed Coral Translocation
Methodology prepared under Condition 2.6 of the EP-354/2009A.
1.4
Purpose of this Report
This
Detailed Coral Translocation Methodology is prepared for the coral
translocation exercise of the Southern Connection Viaduct Section of
TM-CLKL. In accordance with Condition 2.6 of
the EP-354/2009A, the
following information is presented in this document:
l
Findings of the pre-construction
surveys which were undertaken at the donor site at Tai Ho Wan and at the
proposed coral receptor site at Tai Mo To in December
2012 and January 2013;
l
Identification of receptor site(s)
for the translocated corals from Tai Ho Wan;
l
Details of the proposed procedures
for the pre-translocation survey;
l
Coral translocation method; and
l
Post-translocation
monitoring method.
This
Detailed Coral Translocation Methodology will be submitted to the DEP for
approval at least one month before the commencement of construction of the Southern
Connection Viaduct Section of the TM-CLKL.
2
PRE-CONSTRUCTION SURVEY
2.1
Pre-Construction
Survey at the Donor Site
Spot-check dives and Rapid
Ecological Assessment (REA) surveys were conducted at the donor site at Tai Ho
Wan. The seabed of the survey site
was mainly composed of natural bedrocks, boulders, artificial sloping boulders,
and artificial vertical seawall.
Two coral species (one hard coral and one gorgonian species) were
recorded during the surveys. The
survey results at Tai Ho Wan are presented in the following sections.
Tai Ho Wan
2.1.1
Spot Check Dive
A total of 12
spot-check dives were carried out on 17th – 19th December
2012 (Figure 2.1). The seabed of the survey sites (THW01 to
THW12) were composed of artificial sloping boulders and sandy / muddy substrates, with water depth ranging from 1 to 7.5
m. The survey sites supported
limited marine life. One hard coral
species and one gorgonian species were found on boulder surfaces at spot-check
dive sites THW01 to THW04. They
were ahermatypic cup coral Balanophyllia sp. and gorgonian Guaiagorgia sp. The
coral species recorded are common in local Hong Kong
waters. The percentage cover of the
corals found was low (<1%) (Table 2.1).
Table
2.1 Species,
Coverage and Size of Corals Found at Spot-Check Dive Sites at Tai Ho Wan
|
Site |
Coral Species |
Coverage (%) |
Size in Height/ Diameter (cm) |
|
THW01 |
Balanophyllia sp. |
<1% |
<1 |
|
Guaiagorgia sp. |
<1% |
10-15 |
|
|
THW02 |
Balanophyllia sp. |
<1% |
<1 |
|
Guaiagorgia sp. |
<1% |
10-15 |
|
|
THW03 |
Balanophyllia sp. |
<1% |
<1 |
|
Guaiagorgia sp. |
<1% |
10-15 |
|
|
THW04 |
Balanophyllia sp. |
<1% |
<1 |
|
Guaiagorgia sp. |
<1% |
10-15 |
2.1.2
REA
Two 100 m
Table
2.2 Ecological
and Ecological Attributes of the REA Transects at Tai Ho Wan
|
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) |
5 |
5 |
|
Boulders
Blocks (diam. <50cm) |
3 |
3 |
|
Rubble |
0 |
0 |
|
Other |
0 |
0 |
|
Sand |
2 |
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 Tai Ho Wan
|
Benthic Taxon |
REA 1 (1) |
REA 2 (1) |
|
Balanophyllia sp. |
2 |
2 |
|
Guaiagorgia sp. |
2 |
2 |
|
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 |
||
Sparse
and patchy coverage (<1%) of hard coral (Balanophyllia
sp.) and gorgonian (Guaiagorgia sp.) were recorded during the
REA surveys. A total of 67 colonies
of Guaiagorgia
sp. (10 – 15 cm in height) were recorded on boulder surfaces along the REA
transects at an average depth of 4 m.
In addition, patches of Balanophyllia sp. were also found on the
boulder surfaces along the shoreline with very low coverage (<1%). The recorded corals were in fair health
condition.
Nine
(9) out of the 67 recorded coral colonies were attached to movable boulders
(<50 cm in diameter). It is considered technically
feasible to translocate these movable boulders to reduce the direct loss of
corals. Prior to coral
translocation, a more detailed pre-translocation survey is recommended to find out the exact number of coral colonies
(both movable and non-movable) within the affected area.
Overall, all the corals (Balanophyllia sp. and Guaiagorgia sp.) recorded during the REA survey
are widespread and common across Hong Kong waters especially in the western
waters with very low visibility.
Owing to their commonness, sparse cover (< 5%), small size (most of the
corals) and low species diversity and richness, the coral habitat of the
surveyed area is considered as of low ecological value.
Detailed results of the dive surveys are provided in Appendix A.
Representative photographs of the habitats and species recorded are
shown in Appendix B.
2.2
Pre-construction Survey at the Receptor Site (Tai Mo To)
Spot-check dives and REA surveys
were conducted at the receptor site (Tai Mo To) proposed in the approved EIA Report in December 2012
and January 2013. The seabed of the
survey site was mainly composed of natural bedrocks and boulders. Two coral species (one hard coral and one gorgonian species) were recorded
during the surveys.
2.2.1
Spot-Check Dive
A total of six
spot-check dives were carried out on 13th December 2012 (Figure 2.3). The
seabed of the survey sites (TMT01 to THW06) were composed of bedrocks, boulders and sandy / muddy substrates,
with water depth ranging from 1.5 to 7.5 m. The survey sites supported limited
marine life. One hard coral species
and one gorgonian species were found on boulder surfaces at spot-check dive
sites TMT01 and TMT02. They were
ahermatypic cup coral Balanophyllia sp. and gorgonian Guaiagorgia sp. The
coral species recorded are common in local Hong Kong
waters. The percentage cover of the
corals found were low (<1%) (Table 2.4).
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 |
2.2.2
REA
A 100 m REA transect was surveyed on 10th
January 2013 following the spot-check dives (Figure 2.4). Tables 2.5-6 summarize the ecological and
substratum attributes, and the ranks of taxon abundance along the REA transect.
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 |
Sparse and patchy coverage (<1%)
of hard coral (Balanophyllia sp.) and gorgonian (Guaiagorgia sp.) were recorded during the REA survey. A total of 57 colonies of Guaiagorgia sp. (10 – 25 cm in height) were recorded on bedrock or boulder
surfaces along the REA transect at an average depth of 3.5 m. In addition, patches of Balanophyllia sp. were also found on the boulder surfaces along the shoreline with
very low coverage (<1%). All
recorded corals were in fair health condition.
Detailed results of the dive surveys
are provided in Appendix A.
Representative photographs of the habitats and species recorded are
shown in Appendix B.
2.3
Alternative
Coral Receptor Site
The EIA
of the Project recommended that an area around Tai Mo To could be a suitable
location for the receptor site.
However, when
compared with the donor site at Tai Ho Wan, the underwater visibility at the suggested
coral receptor site at Tai Mo To was very low during the spot-check dives and REA surveys and the site is very exposed.
Since post-translocation monitoring is required after coral
translocation, the very low underwater visibility and rough sea conditions at
Tai Mo To would make it difficult to find the translocated corals at the
site. In addition, the
translocated corals may be displaced easily if the wave is too strong. Therefore, it is recommended to find a more suitable receptor
site which is less exposed and with similar coral assemblages to the donar site (ie
with presence of Guaiagorgia sp. and Balanophyllia sp.). Recent coral surveys undertaken under Contract No. HY/2011/03 Hong
Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between Scenic Hill and
Hong Kong Boundary Facilities showed that Guaiagorgia sp. and Balanophyllia sp. were found at Yam Tsai Wan of North Lantau which is a relatively
less exposed site (Figure 2.5). It should also be noted that Yam Tsai
Wan was selected as the receptor site for the coral translocation exercise of Contract No. HY/2011/03 under which corals had
been translocated successful to this receptor site in October 2012. Considering the above, it is recommended
to select Yam Tsai Wan as the coral receptor site for the present translocation
exercise of the Southern
Connection Viaduct Section.
3
rEQUIREMENT OF
PRE-TRANSLOCATION CORAL SURVEY
3.1
Pre-Translocation and Translocation Surveys
at the Donor Site
A coral mapping survey will be conducted at the donor
site at Tai Ho Wan as part of the pre-translocation coral survey. The location of the donor site is shown
in Figure
2.2.
The location of any hard corals and gorgonians will be
mapped. The size and health
condition (including percentage cover of bleaching, mortality, degree of
sedimentation) of the corals will be recorded. The feasibility of translocation of
corals including but not limited to those of conservation importance will be
assessed.
Coral colonies (i.e.
those attached to movable boulders with diameter <50 cm, in good health condition, and
feasible for translocation) proposed to be translocated will be identified, mapped and tagged
during the survey. Each coral colony will be tagged using laminated,
waterproof labels (approximately 20 cm x 10 cm), which will be tied onto
boulders just adjacent to the coral colonies. Photograph(s) of each coral colony will
be taken and additional information for each of the coral colonies will also be
collected (e.g. depth, orientation, size of the attached boulders, general
conditions immediately surrounding the coral colonies).
Substratum removal method is not
suggested for translocating the two coral species (Balanophyllia
sp. and Guaiagorgia sp.) found at Tai Ho Wan. This is because the hard coral species Balanophyllia sp. is in encrusting growth form on the attached substrate. In addition, Balanophyllia
sp. is a solitary coral species with single, small size polyp (ie mostly not
larger than 5 mm in diameter for each individual) attached to the
substrate. Substratum removal
method would not be feasible as that would likely to damage the coral colonies
and lead to a very low chance of survival during the translocation
process. For the azooxanthellate
gorgonian Guaiagorgia sp., it depends on filter feeding
with the tentacles capturing plankton and particulate matter from the water column. At the receptor site, it would be
necessary to attach (or glue) them using epoxy or underwater cement to the seabed
of an area with relatively stronger current to facilitate their filter feeding
process. High mortality of
gorgonian is expected at the receptor site due to the following reasons:
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.
Considering the above and the lack
of local experiences in adopting substratum removal method for gorgonian
translocation, the substratum removal method is not recommended for the target
translocated coral species at Tai Ho Wan.
Since 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.
Further details on the coral translocation procedure are
presented in Section 4.
3.2
Pre-Translocation Survey at the Receptor Site
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. 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 Tai Ho Wan. 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 Balanophyllia
sp. 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:
· Gorgonian
coral: Percentage of branches
exhibiting partial mortality and secretion of mucus.
· Hard coral: Percentage of surface area exhibiting
partial mortality and blanched/ bleached area using specially designed Coral
Health Monitoring Chart (Appendix C).
The
benthic cover (Tier I) and taxon abundance (Tier II) of the
transect will be assessed in a swathe 2 m wide, 1 m either side of the
transect. Two assessment categories
(Tiers) will be used in the surveys, as follows:
Tier I – Categorization of Benthic
Cover
Upon the completion of each
transect, ecological and substratum attributes (Table 3.1) will be
assigned to standard ranked ordinal categories (Table 3.2).
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 – 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:
· Hard corals to
species, where possible;
· Soft corals,
anemones and conspicuous macroalgae to genus level, where possible;
· 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).
4
Coral translocation method
4.1
Coral Translocation Procedures
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.
4.2
Precautionary
Measures of Coral Translocation
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.
4.3
Preliminary Coral
Translocation Schedule
According
to the preliminary schedule of coral translocation, the coral translocation
exercise, including pre-translocation survey and coral translocation, will
commence in October 2013 for completion within five days (please refer to Table 6.1 in Section 6).
5
Post-translocation coral monitoring
5.1
Monitoring Methodology
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. |