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
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-1. 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 5th
and 10th July 2013. The dolphin
monitoring schedule for the reporting period is shown in Appendix D.
6.8
From
these surveys, a total of 60.3
km of survey effort was collected, with 100.0% of the total survey effort being conducted under favourable weather conditions (i.e. Beaufort Sea State 3 or
below with good visibility) Out of the 60.3 km of survey effort, the total
survey effort conducted on primary lines (the vertical lines perpendicular to
the coastlines) was 40.2 km.
6.9
15 groups of 63 Chinese White Dolphins were
sighted from primary lines.
These sightings were evenly distributed throughout the WL survey area,
which was very different from previous months of monitoring when most sightings
were made at the middle and southern portions of the survey area. Notably, two
dolphin sightings were made near the HKLR09 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 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 5th |
38.7 |
159.5 |
Set 2: July 10th |
35.8 |
153.5 |
6.11 A
total of 28 re-sightings of known individual Chinese White Dolphins were made
during the July’s surveys.
6.12 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-1.
6.15 According
to EM&A Manual Section 10.3.3 and 10.4.2, construction-phase underwater noise
monitoring has to be carried out to verify the assessment outcome in the EIA
and to collect field data of this construction activity. The actual underwater noise level of bored
piling will be monitored during the pile construction in the waters to the west
of the Airport for HKLR.
6.16 Following
the requirement in the EM&A Manual Section 10.6.2,
construction-phase underwater noise
monitoring will be constructed for 10 days from the start of the bored piling
activities for the first three pier sites during the bored piling process in
the first three sits in the waters to the west of Airport.
6.17 The equipment was
positioned at an appropriate and
safe distance from a barge (about 100m away from the center of the pier) where
the piling work was carried out at the pier site to monitor the underwater
noise during the bored piling activities. After anchoring, the boat
would drift within the radius of the anchor (about 5m), which was unavoidable.
6.18 In
July 2013, bored piling work was carried out at Pier site no. 0. The
approximate locations of the monitoring stations are depicted in Figure 5. The co-ordinates of the
monitoring station are shown in Table
6.3.
Table
6.3 Co-ordinates
of underwater noise monitoring stations
Pier No. |
Station |
Easting |
Northing |
0 |
R3 |
802556 |
815708 |
6.19 Due
to programme change, the first three piers were
changed to P48, P52 and P0 instead of P20, P47 or P49 proposed in the
methodology statement. While the location of impact monitoring has changed, the
position of the station remained around 100m away from the piers as proposed.
The change in monitoring location will not affect comparison against Action and
Limit level.
6.20 R3
was monitored on 11th, 12th, 15th-19th
and 22nd-24th July 2013. A total of 10 days of underwater noise monitoring were conducted at R3
during the bored piling activities for P0. The underwater noise monitoring
schedule for the reporting period is shown in Appendix D. Since the
commencement of the underwater noise monitoring, a total of 30-day results from
the start of the bored piling activities for the first three pier sites were
collected.
6.21 PAM004, a proprietary product of Sea Mammal
Research Unit (SMRU), was adopted for impact underwater noise monitoring. It is
the same equipment used in baseline monitoring. While this is different
from the system proposed in the method statement, the difference in
sensitivity and pre-amplifier gain will not affect the monitoring results.
Therefore, this still allows compatible comparison of the measurement. Copies of calibration certificates are provided in Appendix C.
6.22 The data recorded by PAM004 were transmitted
to a receiving station on a boat via cable. The data were viewed on a laptop computer in real time by an operator from Cinotech who has been well trained and technically
supported by SMRU for the operation.
6.23 The RMS sound
pressure level re 1µPa were checked
against the Action Level and
Limit Level (170 and 180 dB re 1µPa respectively).
6.24 The underwater noise monitoring results are
summarized in Table 6.4. Hourly
average RMS and graphical presentations of underwater noise monitoring are shown in Appendix I-2. The averaging period was in general from
9am to 6pm, depending on the availability of the data as the monitoring might
have temporarily paused due to bad weather or to give way for barge movement.
Table 6.4 Summary Table of Underwater Noise Monitoring
Results during the Reporting Month
Date |
Pier No. |
Station |
Underwater Noise (dB re
1µPa) |
Period |
||
Max |
Average |
Min |
||||
11-Jul-13 |
0 |
R3 |
156.8 |
139.8 |
117.7 |
10-18 |
12-Jul-13 |
0 |
R3 |
164.6 |
139.7 |
115.4 |
9-18 |
15-Jul-13 |
0 |
R3 |
161.6 |
135.3 |
119.7 |
9-18 |
16-Jul-13 |
0 |
R3 |
153.9 |
133.6 |
120.5 |
9-18 |
17-Jul-13 |
0 |
R3 |
149.8 |
134.4 |
120.1 |
9-18 |
18-Jul-13 |
0 |
R3 |
149.9 |
138.4 |
122.5 |
9-18 |
19-Jul-13 |
0 |
R3 |
159.1 |
138.8 |
120.3 |
9-18 |
22-Jul-13 |
0 |
R3 |
155.2 |
140.0 |
122.2 |
9-18 |
23-Jul-13 |
0 |
R3 |
154.8 |
141.9 |
122.4 |
9-18 |
24-Jul-13 |
0 |
R3 |
155.1 |
141.2 |
120.8 |
9-18 |
Remarks: All underwater noise
monitoring was conducted during the bored piling activities
Frequency: 70 Hz – 125 kHz
6.25 As shown in the table above, no Action/Limit
Level exceedance was recorded.
6.26
A total
of 30-day results from the start of the bored piling activities for the first
three pier sites were collected, further analysis on PSD and within audiological range of frequencies of Chinese
white dolphin will be carried out and presented in a separate report.
6.27
Should
non-compliance of the criteria occur, action in accordance with the Action Plan
in Appendix K shall be carried out.
6.28 According
to EM&A Manual Section 10.3.4, acoustic behavior
and movement of Chinese White Dolphin near the bored piling sites should be
monitored during bridge construction.
6.29 The
dedicated acoustic surveys with calibrated hydrophone deployment were conducted
in the western side of Lantau Island during the
construction phase. The research vessel followed a predefined route for
systematic search effort in West Lantau waters to
cover the HKLR alignment in Northwest and West Lantau
waters (in particular the area near the first three bored piling sites), where
dolphins will be potentially disturbed by the bored piling works.
6.30 The
EARs were deployed at two locations: 1) near the bridge alignment (N22°17.222,
E113°53.016), about 500 m from the first three bored piling sites (Site B2),
and 2) at a less disturbed site away from the bridge alignment as control site,
off Fan Lau (N22°11.827, 113°50.648; Site B1). EAR B2 was in water depth 4 m, and EAR B1 in 7 m.
6.31 In
July 2013, a total of 12 days of acoustic monitoring surveys were conducted on
the 9th, 11th, 12th, 15th, 16th,
17th, 18th, 22nd, 23rd, 24th,
25th and 26th, when bored piling activities were
concurrently conducted. The schedule
is shown in Appendix D.
6.32 In
July, 783.8 km of survey effort
were conducted to search for dolphins in the western and northwestern waters of
Lantau. A
total of 46 groups, numbering 170 dolphins, were sighted during these
surveys. In addition, 52 sound
samples with 4.2 hours of recordings were taken from some of these dolphin
groups. Moreover, the EARs were
deployed since early July 2013
at Fan Lau (site B1) and near the bridge alignment (Site B2), which will be
recovered at the end of the construction phase monitoring.
6.33 Detailed
monitoring methodology and results can be found in Appendix I-3.
6.34 According
to EM&A Manual Section 10.3.5, land-based theodolite
tracking has to be carry out to study dolphin behaviour
near bored piling work site, and examine their north-south movement across the
bridge alignment during after bridge construction.
6.35 Following
the requirement in the EM&A Manual Section 10.4.3
and 10.6.3, the monitoring should be conducted at the three pier sites for 30
days from the start of bored piling activities in the waters to the west of
Airport.
6.36 A
theodolite tracking station was set up in Sham Wat located along the northwest coast of Lantau Island (22o16.10’ N. and 113o52.32’
E) as depicted in Figure 6.
6.37 Thirty
days of monitoring would be carried out during the construction phase. Additional land-based dolphin behavior and
movement monitoring (twice per month) throughout the construction period will be
commenced subject to the detailed analysis of 30 days monitoring results.
6.38 In July 2013, a total of 13 sessions with
74.1 hours of theodolite tracking were conducted from
Shum Wat shore-based station on the 8th, 9th,
10th, 11th, 12th, 13th, 15th,
17th, 18th, 19th, 23rd, 24th
and 29th, when bored piling activities were concurrently conducted. The
schedule is shown in Appendix D.
6.39 More
than 93% of effort was conducted in favourable
weather conditions during those days.
Dolphins were successfully tracked from shore on 12 of the 13 days of
efforts, and a total of 57 dolphin groups were tracked. A total of 1,536 fixes of their
positions were collected, and another 2,174 fixes were also made from locations
of various vessels (e.g. fishing boats, high-speed ferries), to examine the
level of vessel traffic in the study area.
At the end of the construction phase monitoring period, the data will be
used for the analyses on movement pattern, speed, reorientation rate,
linearity, inter-breath interval, and north-south movement of Chinese White
Dolphins.
6.40 Detailed
monitoring methodology and results can be found in Appendix I-4.