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 9th and 17th April 2013. The dolphin monitoring schedule for the reporting period is shown in Appendix D.
6.8 From these surveys, a total of 62.3 km of survey effort was collected, with 93.7% of the total survey effort being conducted under favourable weather conditions. Out of the 62.3 km of survey effort, the total survey effort conducted on primary lines (the vertical lines perpendicular to the coastlines) was 43.6 km.
6.9 4 groups of 16 Chinese White Dolphins were sighted from primary lines, mainly at the southern portion of the survey area near Peaked Hill and Fan Lau, and were located far away from the HKLR09 alignment during this month’s monitoring surveys. None of the dolphin groups was associated with an operating fishing vessel.
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 9th |
11.2 |
61.5 |
|
Set 2: April 17th |
9.2 |
22.9 |
|
6.11 A total of 22 re-sightings of known individual Chinese White Dolphins were made during the April’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 April 2013, bored piling work was carried out at Pier site no. 48 and 52. 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 |
|
48 |
R1 |
806141 |
815885 |
|
52 |
R2 |
806390 |
816056 |
6.19 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 will not affect comparison against Action and Limit level.
Monitoring Day
6.20 R1 was monitored on 25th, 26th and 30th April 2013 while R2 was monitored on 2nd, 3rd, 5th, 8th-11th, 27th and 29th April 2013. A total of 3 days and 8 days of underwater noise monitoring were conducted at R1 and R2 respectively during the bored piling activities for P48 and P52. The underwater noise monitoring schedule for the reporting period is shown in Appendix D. The underwater noise monitoring will be continued so that 30 days results from the start of the bored piling activities for the first three pier sites can be 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.
Table 6.4 Summary Table of
Underwater Noise Monitoring Results during the Reporting Month
|
Date |
Station |
Underwater Noise (dB re
1µPa) |
||
|
Max |
RMS |
Min |
||
|
*2-Apr-13 |
R2 |
155.8 |
129.5 |
110.8 |
|
*3-Apr-13 |
R2 |
147.1 |
125.5 |
111.8 |
|
*5-Apr-13 |
R2 |
156.7 |
129.8 |
111.6 |
|
*8-Apr-13 |
R2 |
157.2 |
128.7 |
109.4 |
|
*9-Apr-13 |
R2 |
155.2 |
130.3 |
112.3 |
|
*10-Apr-13 |
R2 |
146.6 |
129.1 |
112.7 |
|
11-Apr-13 |
R2 |
145.0 |
128.8 |
111.0 |
|
*25-Apr-13 |
R1 |
156.6 |
129.8 |
112.3 |
|
*26-Apr-13 |
R1 |
163.9 |
129.3 |
113.9 |
|
*27-Apr-13 |
R2 |
149.8 |
134.0 |
118.5 |
|
*29-Apr-13 |
R2 |
160.1 |
133.9 |
113.8 |
|
*30-Apr-13 |
R1 |
146.9 |
132.3 |
112.9 |
Remarks: *
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 Further analysis on PSD and within audiological range of frequencies of Chinese white dolphin will be carried out after completion of the whole impact monitoring work.
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 April 2013, a total of 8 days of acoustic monitoring surveys were conducted on the 1st, 2nd, 3rd, 5th, 7th, 8th, 10th and 11th April 2013, when bored piling activities were concurrently conducted at Piers 48 and 52. The schedule is shown in Appendix D. The acoustic monitoring surveys will be continued so that 30 days results during the bored piling activities will be collected.
6.32 In April, 524.4 km of survey effort were conducted to search for dolphins in the western and northwestern waters of Lantau. A total of four groups, numbering seven dolphins, were sighted during these surveys. In addition, two sound samples with 10 minutes of recordings were taken from some of these dolphin groups. Moreover, the EARs were deployed since February 25th, 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.
6.38 In April 2013, a total of 9 sessions with 52.67 hours of theodolite tracking were conducted from Sham Wat shore-based station on April 1st, 2nd, 4th, 5th, 7th, 8th, 9th, 10th and 11th April 2013, when bored piling activities were concurrently conducted at Piers 48 and 52. The schedule is shown in Appendix D. The land-based theodolite tracking will be continued so that 30 days results during the bored piling activities will be collected.
6.39 More than 80% of effort was conducted in favourable weather conditions during those days. Dolphins were successfully tracked from shore on two of the nine days of efforts, and a total of three dolphin groups were tracked. A total of 93 fixes of their positions were collected, and another 2,314 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.