6.1
According
to Section 10 of the EM&A Manual, four kinds of ecological monitoring works
are required during the construction phase, namely dolphin monitoring,
construction-phase underwater noise monitoring, dolphin behavior monitoring and
land-based dolphin behavior and movement monitoring. The 30 days of construction-phase underwater noise
monitoring, dolphin behavior monitoring and land-based dolphin behavior and
movement monitoring were completed in July 2013.
6.2
The
monitoring work shall be undertaken by suitably qualified specialist(s), (i.e.
dolphin specialist and bio-acoustician), who shall have sufficient (at least
5-10 years) relevant post-graduate experience and publication in the respective
aspects. They should be approved by Agriculture, Fisheries and Conservation
Department (AFCD) and Environmental Protection Department (EPD).
6.3
According
to EM&A Manual Section 10.3.2, a dolphin monitoring programme should be set
up to verify the predictions of impacts and to ensure that there are no
unforeseen impacts on the dolphin population during construction phase.
6.4
Following
the requirement in the EM&A Manual Section 10.4.1, the dolphin monitoring
should adopt line-transect vessel survey method, and cover the following
line-transect survey areas as in AFCD annual marine mammal monitoring
programme.
6.5
For
this contract, dolphin monitoring will be carried out in the West Lantau (WL)
along the line transect as depicted in Figure
1 of Appendix I. The co-ordinates of all transect lines are
shown in Table 6.1.
Table 6.1 Co-ordinates
of transect lines in WL survey area
Line No. |
Easting |
Northing |
Line No. |
Easting |
Northing |
||
1 |
Start Point |
803750 |
818500 |
7 |
Start Point |
800200 |
810450 |
1 |
End Point |
803750 |
815500 |
7 |
End Point |
801400 |
810450 |
2 |
Start Point |
803750 |
815500 |
8 |
Start Point |
801300 |
809450 |
2 |
End Point |
802940 |
815500 |
8 |
End Point |
799750 |
809450 |
3 |
Start Point |
802550 |
814500 |
9 |
Start Point |
799400 |
808450 |
3 |
End Point |
803700 |
814500 |
9 |
End Point |
801430 |
808450 |
4 |
Start Point |
803120 |
813600 |
10 |
Start Point |
801500 |
807450 |
4 |
End Point |
801640 |
813600 |
10 |
End Point |
799600 |
807450 |
5 |
Start Point |
801100 |
812450 |
11 |
Start Point |
800300 |
806500 |
5 |
End Point |
802900 |
812450 |
11 |
End Point |
801750 |
806500 |
6 |
Start Point |
802400 |
811500 |
12 |
Start Point |
801760 |
805450 |
6 |
End Point |
800660 |
811500 |
12 |
End Point |
800700 |
805450 |
6.6
Dolphin
transect survey was carried out at least twice a month (i.e. complete all the
transect lines of West Lantau survey area twice per month) throughout the
construction period.
6.7
Dolphin
monitoring was carried out on 9th and 22nd November 2017. The dolphin
monitoring schedule for the reporting period is shown in Appendix D.
6.8
From these surveys, a total of 66.70 km of
survey effort was collected, with 54.0% of the total survey effort being conducted
under favorable weather conditions (i.e. Beaufort Sea State 3 or below with
good visibility) Out of the 66.70 km of survey effort, the total survey effort
conducted on primary lines (the horizontal lines perpendicular to the
coastlines) was 43.80 km.
6.9
5 groups of 14 Chinese White Dolphins were
sighted from primary lines. Notably, none of the dolphin groups were associated
with any operating fishing vessel. All five dolphin groups were sighted in the
northern portion of the survey area, with two sightings made at the northern
end (i.e. to the west of the airport) and another three made near the Tai O
Peninsula (Figure 4 of Appendix D). On the contrary, they were mostly absent from the central and southern
portions of the survey area (Figure 4 of Appendix D).
6.10
Dolphin
encounter rates deduced from the survey effort and on-effort sighting data made
under favourable conditions (Beaufort 3 or below) are shown in Table 6.2.
Table 6.2 Dolphin
encounter rates (sightings per 100 km of survey effort) in November’s
surveys
|
Encounter rate (STG) (no. of on-effort dolphin
sightings per 100 km of survey effort) |
Encounter rate (ANI)
(no.
of dolphins from all on-effort sightings per 100 km of survey effort) |
|
Primary Lines Only |
Primary Lines Only |
||
WL |
Set 1: November 9th |
19.4 |
38.7 |
Set 2: November
22nd |
0.0 |
0.0 |
6.11
The
average group size of Chinese White Dolphins was 4.8 individuals per group
during November’s surveys, which was higher than the averages in previous
months of monitoring surveys.
6.12
Three
of the five dolphin groups were small in size with only 1-2 animals per group,
while there was a medium-sized dolphin group with six animals.
6.13
During
this month of dolphin monitoring, no major marine construction activities was
conducted and no adverse impact on Chinese white dolphins was noticeable from
general observations.
6.14
There was an Action Level exceedance of dolphin
monitoring for the quarterly monitoring data (between September to November
2017). The exceedance
will be reported and evaluation of impacts on dolphins due to construction work
will be conducted in the quarterly EM&A report.
6.15
Detailed
monitoring methodology and results can be found in Appendix I.
6.16 A total of 64 days of additional monitoring
according to the Proposal for Land-based Dolphin Behaviour and Movement
Monitoring had been completed in August 2016.
6.17 The Final Report of Land-based Monitoring on
North-South Movement of Chinese White Dolphins in West Lantau Waters had been
submitted to EPD on 28 July 2017.
6.18 Detailed
monitoring methodology and results will be provided in a separate report.