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 2nd and 9th October 2018. The dolphin
monitoring schedule for the reporting period is shown in Appendix D.
6.8
From these surveys, a total of 65.78 km of
survey effort was collected, with 100% 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
65.78 km
of survey effort, the total survey effort conducted on primary lines (the
horizontal lines perpendicular to the coastlines) was 42.77 km.
6.9
During the monitoring surveys conducted in
October 2018, nine groups of 29 Chinese White Dolphins were sighted. All nine dolphin groups were sighted
during on-effort search, with seven of them being sighted on primary
lines. None of the dolphin groups
was associated with any operating fishing vessel during the monitoring month. Distribution
of the dolphin sightings made during October’s surveys is shown in Figure
4. The majority of the dolphin
groups were sighted in the southern portion of the WL survey area between Kai
Kung Shan and Fan Lau (Figure 4 of
Appendix I). In addition, two
groups were sighted near Tai O Peninsula (Figure
4 of Appendix I). Notably, none
of the dolphin groups was sighted near the HKLR09 alignment.
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 April’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: October 2nd |
18.7 |
84.0 |
|
Set 2: October 9th |
14.1 |
37.5 |
|
6.11 The average
group size of Chinese White Dolphins was 3.2 individuals
per group during
October’s surveys,
which was lower than the averages in previous months of monitoring surveys.
6.12 In this month of dolphin
monitoring, marine construction activities have continued under this contract. However,
no adverse impact on Chinese white dolphins was noticeable from general
observations.
6.13 Detailed monitoring methodology
and results can be found in Appendix I.
6.14
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.
6.15
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.