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 10th and 19th July 2018.
The dolphin
monitoring schedule for the reporting period is shown in Appendix D.
6.8
From these surveys, a total of 62.95 km of survey effort was
collected, with 95.5% 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 62.95 km of survey effort, the
total survey effort conducted on primary lines (the horizontal lines
perpendicular to the coastlines) was 42.1 km.
6.9
During the monitoring surveys conducted in July
2018, ten groups
of 30 Chinese White Dolphins were sighted. All groups
were sighted from primary lines. All ten dolphin groups were sighted during on-effort search, with seven
of them being sighted on primary lines.
Notably, one dolphin group was associated with an operating purse-seiner
near Peaked Hill during the monitoring month. Distribution
of the dolphin sightings made during July’s surveys is shown in Figure 4. The dolphins groups were evenly
distributed in the central portion of WL survey area from Tai O Peninsula to
Peaked Hill (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: July 10th
|
10.3 |
36.0 |
Set
2: July
19th |
19.5 |
39.0 |
6.11
The average group size of Chinese White
Dolphins was 3.0 individuals
per group during July’s surveys, which was slightly lower than the averages in previous months of
monitoring surveys.
6.12
Although marine construction
activities have continued under this contract, 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.