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 4th and 13th July 2017. The dolphin monitoring schedule for the
reporting period is shown in Appendix D.
6.8
From these surveys, a total of 65.61 km of survey effort was
collected, with 90.8% 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 65.61 km of survey effort, the
total survey effort conducted on primary lines (the horizontal lines
perpendicular to the coastlines) was 42.49 km.
6.9
8 groups of 18 Chinese White Dolphins were sighted from primary lines.
Notably, none of the dolphin groups were associated with any operating fishing
vessel. The dolphin groups were evenly distributed in the central portion of the
survey area, mainly from Tai O Peninsula to Peaked Hill with no particular
concentration (Figure 4 of Appendix D). However, they were mostly absent from
the northern and southern ends of the survey area, with the exception of a
dolphin group sighted near Fan Lau (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 July’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 4th |
9.3 |
28.0 |
Set
2: July 13th |
11.1 |
22.2 |
6.11
The average group size of
Chinese White Dolphins was 2.3 individuals per group during July’s surveys, which
was slightly lower than the averages in previous months of monitoring surveys.
6.12
All except one dolphin group
were small in size with only 1-3 animals per group, while there was only a
medium-sized group of five animals sighted near Fan Lau.
6.13
During 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.
6.14
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
Detailed monitoring methodology and results will be provided in a
separate report.