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 7th and 15th October 2015. The dolphin monitoring schedule
for the reporting period is shown in Appendix
D.
6.8
From these surveys, a total of 68.25 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 66.28 km of survey effort,
the total survey effort conducted on primary lines (the horizontal lines
perpendicular to the coastlines) was 45.84
km.
6.9
6 groups of 18 Chinese White
Dolphins were sighted from primary lines. Distribution of the 8 dolphin sightings made during October’s surveys is
shown in Figure 4 of Appendix I. These sightings
were evenly distributed throughout the survey area without any particular
concentration, but there appeared to be more sightings made in the offshore
waters near the HKSAR Boundary in this monitoring month. Although almost all dolphins were
sighted far away from the HKLR09 alignment, two sightings were made within a kilometre from the artificial island connecting the HKLR09
alignment (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 October’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 7th |
13.3 |
66.7 |
Set
2: October 15th |
12.8 |
12.8 |
6.11
The average group size of Chinese White Dolphins was 4.1 individuals
per group during October’s surveys, which
was slightly higher than the ones in previous months of monitoring surveys.
6.12
Eight of the 11 dolphin groups
were composed of only 1-2 animals, while there were two larger groups with 6-8
animals pre group and one exceptionally large group with 22 animals sighted
during this monitoring month.
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
Additional land-based dolphin behavior and movement monitoring was
conducted on 2nd and 14th October 2015 in the reporting
month. The progress of the monitoring is summarized in the Table 6.3.
Table 6.3 Progress
Record of Additional Land-based Dolphin Behaviour and
Movement Monitoring in October 2015
Date |
Time |
Weather |
Number of Staff |
Number of Dolphin Sighting |
|
Beaufort |
Visibility |
||||
02/10/2015 |
08:56
- 14:17 |
2 |
1.5 |
3 |
2 |
14/10/2015 |
08:58
- 14:28 |
2 |
3 |
3 |
1 |
6.17
Detailed monitoring methodology and results will be provided in a
separate report after the completion of full set of additional land-based
dolphin behavior and movement monitoring.