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 August
2018. The dolphin
monitoring schedule for the reporting period is shown in Appendix D.
6.8
From these surveys, a total of 66.52 km of survey effort was
collected, with 98.1% 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 66.52 km of survey effort, the
total survey effort conducted on primary lines (the horizontal lines
perpendicular to the coastlines) was 43.27 km.
6.9
During the monitoring surveys conducted in August 2018, 16 groups of
65 Chinese White Dolphins were sighted.
Fourteen of the 16 dolphin groups were sighted during on-effort search,
with nine 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 August’s surveys is shown in Figure 4 of Appendix I. The majority of the dolphin groups were
sighted along the WL coastline between Yi O and Peaked Hill, while several
sightings were also made to the north of Tai O Peninsula and near the HKLR09
alignment. Only one dolphin was sighted at the southern end of the WL survey
area near Fan Lau (Figure 4 of Appendix
I).
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: August 2nd
|
9.3 |
101.9 |
Set
2: August
9th |
34.3 |
132.2 |
6.11
The average group size of Chinese White
Dolphins was 4.1 individuals per group during August’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.