5.1
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.
5.2
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).
5.3
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.
5.4
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.
5.5
For this contract, dolphin monitoring will be carried out in the
West Lantau (WL) along the line transect. The co-ordinates of all transect
lines are shown in Table 5.1 and the
transect line layout in West Lantau Survey Areas are shown in Figure 7.
Table 5.1 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 |
5.6
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.
Monitoring Results and Observations
5.7
Detailed monitoring methodology and results can be found in the monthly
EM&A report.
5.8
A total of 3 Action Level exceedance and 1 Limit Level exceedance
were recorded during the construction phrase of the Contract. The summary of exceedance is attached in Appendix
G.
5.9
According to the ET’s investigation, no direct evidence
demonstrated the exceedances of Action/Limit level for dolphin were caused by
the Contract during the construction period. No adverse impact on Chinese white
dolphins was noticeable from general observations
5.10
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 was monitored during the pile
construction in the waters to the west of the Airport for HKLR.
5.11
Following
the requirement in the EM&A Manual Section 10.6.2, construction-phase
underwater noise monitoring was 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.
5.12
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.
5.13
The
approximate locations of the monitoring stations are depicted in Figure 5. The co-ordinates of the
monitoring station are shown in Table 5.2.
Table 5.2 Co-ordinates of underwater noise
monitoring stations
|
Pier No. |
Station |
Easting |
Northing |
|
48 |
R1 |
806141 |
815885 |
|
52 |
R2 |
806390 |
816056 |
5.14
Due
to programme change, the first two piers were changed to P48 and P52 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 would not
affect comparison against Action and Limit level.
5.15
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.
5.16
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.
5.17
The RMS sound pressure level re 1µPa
were checked against the Action Level and Limit Level (170
and 180 dB re 1µPa respectively).
5.18
Detailed monitoring methodology and results can
be found in the monthly EM&A report. No Action/Limit Level exceedance was
recorded. The graphical presentation of underwater noise monitoring is shown in
Appendix B.
5.19
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.
5.20
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.
5.21
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.
5.22
Detailed monitoring methodology and results can be found in the monthly
EM&A report.
5.23
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.
5.24
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.
5.25
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.
5.26
Thirty
days of monitoring would be carried out during the construction phase.
5.27
Detailed monitoring methodology and results can be found in the monthly
EM&A report.
5.28 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.
5.29
According to Section 10 of approved EIA Report, EM&A Manual
and Section 2 of approved Proposal for Land-based Dolphin Behavior and Movement
Monitoring submitted on 24 January 2013 and approved by the authority on 5
February 2013, land-based theodolite tracking to study dolphin behaviour near
bored piling work site, and examine their north-south movement across the
bridge alignment shall be conducted before, during and after bridge
construction. Summary of the requirements of land-based dolphin monitoring is
shown in Table 5.3:
Table
5.3 Summary of Land-based of Dolphin Behaviour and Movement Monitoring
Requirements
|
EIA |
EM&A
Manual |
Approved
Monitoring Proposal |
|
Requirement for
Land-based of dolphin behaviour and movement monitoring |
||
|
Ÿ Land-based theodolite tracking to study
dolphin behaviour near bored piling work site, and examine their north-south
movement across the bridge alignment before, during and after bridge
construction. |
Ÿ Land-based theodolite tracking to study
dolphin behaviour near bored piling work site, and examine their north-south
movement across the bridge alignment before,
during and after bridge construction. Ÿ The behaviour near the bored piling sites
and north-south movement across the bridge alignment of CWD should be
monitored in the waters to the west of Airport. |
Ÿ Dolphin
behaviour in response to bored piling works and movement near the bored
piling sites should be monitored at the first three pier sites for 30 days
from the start of bored piling activities in the waters to the west of
Airport. However, the number of monitoring days is not well specified for the
baseline period. Ÿ Therefore, reference to the
requirements in the Tuen Mun – Chek Lap Kok Link (TMCLKL) EM&A Manual was
made, in which 30 days of theodolite tracking before(i) and 30 days of theodolite
tracking from the start of bored piling activities(ii) will be conducted under the
present study in order to maintain overall consistency of EM&A Programs
for the Hong Kong-Zhuhai-Macao Bridge (HZMB) development. |
|
Frequency |
||
|
Baseline |
||
|
Ÿ Not specified |
Ÿ Baseline for
dolphin north-south movement across the bridge alignment shall be established
prior to the commencement of works and agreed with AFCD. |
Ÿ 30
consecutive days (with 5-6 hours on each survey day). Ÿ It should be noted that every attempt
will be made to conduct the monitoring in favorable weather conditions
(Beaufort Sea State 3 or below; good visibility of 2km or above). |
|
Impact |
||
|
Ÿ Not specified |
Ÿ Dolphin behavior in response to bored
piling and movement near the bored piling sites will be monitored at the
three pier sites for 30 days from the start of bored piling activities in the
waters to the west of Airport. |
Ÿ 30 consecutive days (with 5-6 hours on
each survey day).
Ÿ It should be noted that every attempt
will be made to conduct the monitoring in favorable weather conditions
(Beaufort Sea State 3 or below; good visibility of 2km or above). Ÿ In the proposal, the dolphin specialist
has also proposed an additional 64 days of monitoring (twice per month, with
5-6 hours on each survey day) throughout the construction period to examine
the impact of bridge construction on north-south movement of CWD across the
bridge alignment. |
|
Post-construction |
||
|
Ÿ Not specified |
Ÿ Not specified |
Not specified |
Construction Program
5.30
The major construction programme of the Contract is provided in Table 5.4.
Table 5.4 Major Construction Program for
Contract No. HY/ 2011/09
|
Description |
Period |
|
Commencement of the Contract |
May 2012 |
|
Construction Commencement |
February 2013 |
|
Piling |
April 2013 – September 2015 |
|
Pile Cap and Piers |
December 2013 – May 2016 |
|
March 2015 – June 2017 |
5.31
Based on the construction programme in Section 5.30, Land-based
theodolite monitoring after bridge construction has been conducted twice per
month from September 2016 to August 2018. A total of 48 days of monitoring was
carried out after the impact monitoring completion. Summary of Land-based
dolphin behavior and movement monitoring across the bridge alignment before,
during and after bridge construction are presented in Table 5.5.
Table
5.5 Summary of Land-based dolphin behavior and movement monitoring across the
bridge alignment before, during and after bridge construction
|
Land-based
dolphin behavior and movement monitoring |
Monitoring
Period |
Monitoring Details |
|
Baseline (before bridge construction) |
Dec 2012 – Jan 2013 |
i)
30 consecutive days before bridge construction (i.e. before start of
bored piling activities) |
|
Impact
(during bridge construction) |
Mar 2013 – Aug 2016 |
i)
30 days from the start of bored piling activities in the waters to the
west of Airport; and ii)
64 days (twice per month) throughout the bridge construction period
(Remark: the pile cap and pier construction under Contract HY/2011/09 were
completed in May 2016) |
|
Post-construction
(after bridge construction) |
Sept
2016 – August 2018 |
i)
48 days (twice per month) after completion of bored piling
activities |
5.32
The Land-based Dolphin Behavior and Movement Monitoring for “baseline”,
“impact” and “after bridge construction” have been conducted by the same
dolphin specialist using consistent monitoring methodology and result
analysis.
5.33
Details of Land-based dolphin behavior and movement monitoring
after bridge construction are presented in the separate Final Report of
Land-based Monitoring on North-South Movement of Chinese White Dolphins in West
Lantau Waters After Bridge Construction.
5.34
All Land-based Dolphin Behaviour and Movement Monitoring have been
completed under Contract No. HY/2011/09 and had fulfilled the requirements
stated in the EM&A Manual.