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 15th and 23rd April 2014. The dolphin monitoring schedule for the reporting period is shown in Appendix D.
6.8 From these surveys, a total of 64.51 km of survey effort was collected, with 75.3% 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 64.51 km of survey effort, the total survey effort conducted on primary lines (the vertical lines perpendicular to the coastlines) was 42.33 km.
6.9 5 groups of 18 Chinese White Dolphins were sighted from primary lines. Dolphins groups were scattered in the waters between Tai O Peninsula and Fan Lau with no apparent concentration of sightings. None of the dolphin sightings was made in the vicinity of the HKLR09 alignment, and the majority of dolphins were sighted far away from the bridge alignment.
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: April
15th |
23.4 |
58.6 |
Set
2: April
23rd |
0.0 |
0.0 |
6.11 The average group size of Chinese White Dolphins was 4.43 individuals per group during April’s surveys, which was slightly higher to the ones in previous months of monitoring surveys.
6.12 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.
6.13 Evaluation of impacts on dolphins due to construction work will be conducted in the quarterly EM&A report.
6.14 Detailed monitoring methodology and results can be found in Appendix I.
6.15 Additional land-based dolphin behavior and movement monitoring was conducted on 16th and 25th April 2014 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 April
2014
Date |
Time |
Weather |
Number
of Staff |
Number
of Dolphin Sighting |
|
Beaufort |
Visibility |
||||
2014/4/16 |
09:05 - 14:49 |
2-3 |
2.5-3 |
3 |
2 |
2014/4/25 |
09:08 - 14:47 |
2-4 |
2 |
3 |
0 |
6.16
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.