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 5th and 11th September 2018. The dolphin
monitoring schedule for the reporting period is shown in Appendix D.
6.8
From these surveys, a total of 64.21 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
64.21 km
of survey effort, the total survey effort conducted on primary lines (the horizontal
lines perpendicular to the coastlines) was 43.52 km.
6.9
During the monitoring surveys conducted in
September 2018, 15 groups of 64 Chinese White Dolphins were sighted. All 15 dolphin groups were sighted
during on-effort search, with eight 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
September’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, a few groups were sighted near Tai O Peninsula and Yi O (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: September 5th |
14.6 |
82.6 |
Set 2: September 11th |
21.8 |
113.3 |
6.11 The average
group size of Chinese White Dolphins was 4.3 individuals
per group during September’s
surveys,
which was slightly higher 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.