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 13th
September 2017. The dolphin monitoring schedule for the reporting
period is shown in Appendix D.
6.8
From these surveys, a total of 67.15 km of survey effort was collected, with 100.0% 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 67.15 km of survey effort, the total survey effort conducted on primary lines
(the horizontal lines perpendicular to the coastlines) was
44.29 km.
6.9
10 groups of 33 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 waters between Tai O Peninsula and Peaked Hill, with
slightly higher concentration near Tai O Peninsula (Figure
4 of Appendix D). On the contrary, they were mostly absent from the northern end of the
survey area (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 September’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 7th |
4.4 |
26.6 |
Set 2: September 13th |
18.4 |
59.9 |
6.11
The average group size of Chinese White Dolphins was 3.3 individuals per
group during September’s surveys, which was similar to the averages in previous
months of monitoring surveys.
6.12
Half of the dolphin groups were small in size with only 1-3 animals per
group, while there were four medium-sized groups of 5-6 animals respectively.
6.13
During this month of dolphin monitoring, no major marine construction
activities was conducted and 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.