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.
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
Since there was no marine bored
piling work in the reporting period, only dolphin monitoring was carried out.
6.4 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.
6.5 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.
6.6 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 |
799800 |
810450 |
|
1 |
End Point |
803750 |
815500 |
7 |
End Point |
801400 |
810450 |
|
2 |
Start Point |
803750 |
815500 |
8 |
Start Point |
801300 |
809450 |
|
2 |
End Point |
802860 |
815500 |
8 |
End Point |
799500 |
809450 |
|
3 |
Start Point |
801880 |
814500 |
9 |
Start Point |
799400 |
808450 |
|
3 |
End Point |
803700 |
814500 |
9 |
End Point |
801430 |
808450 |
|
4 |
Start Point |
803200 |
813600 |
10 |
Start Point |
801500 |
807450 |
|
4 |
End Point |
801500 |
813600 |
10 |
End Point |
799600 |
807450 |
|
5 |
Start Point |
800800 |
812450 |
11 |
Start Point |
800300 |
806500 |
|
5 |
End Point |
803300 |
812450 |
11 |
End Point |
801750 |
806500 |
|
6 |
Start Point |
802500 |
811500 |
12 |
Start Point |
801760 |
805450 |
|
6 |
End Point |
800400 |
811500 |
12 |
End Point |
800600 |
805450 |
6.7 Dolphin transect survey will be 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.
6.8 Dolphin monitoring was carried out on 19th and 25th February 2013. The dolphin monitoring schedule for the reporting period is shown in Appendix D.
6.9 From these surveys, a total of 65.80 km of survey effort was collected, with 83.3% of the total survey effort being conducted under favourable weather conditions. Out of the 65.80 km of survey effort, the total survey effort conducted on primary lines (the vertical lines perpendicular to the coastlines) was 43.45 km, while the effort on secondary lines (the lines connecting the primary lines) was 22.35 km.
6.10 Only one group of four Chinese White Dolphins was sighted in the offshore waters of central portion of West Lantau. The dolphins were engaged in feeding activities following closely behind a shrimp trawler.
6.11 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 February’s surveys
|
|
(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 |
Both Primary and Secondary
Lines |
Primary Lines Only |
Both Primary and
Secondary Lines |
|
|
West Lantau |
2.9 |
1.8 |
11.6 |
7.3 |
6.12 No photograph was taken during the February’s surveys.
6.13 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.