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Contract No. HY/2011/03

Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road

Section between Scenic Hill and Hong Kong Boundary Crossing Facilities

 

 

 

 

 

 

Quarterly EM&A Report No. 13 (Sep 2015 to Nov 2015)

 

18 April 2016

 

Revision 1

 

 

 

 

 

 

 

 

 

 

 

 

 

Main Contractor                                                                                                                     Designer

Atkins new logo
 

 


 


Contents

Executive Summary

1...... Introduction.. 1

1.1                          Basic Project Information. 1

1.2                          Project Organisation. 1

1.3                          Construction Programme. 1

1.4                          Construction Works Undertaken During the Reporting Period. 1

2....... EM&A Requirement 1

2.1                          Summary of EM&A Requirements. 1

2.2                          Action and Limit Levels. 2

2.3                          Event Action Plans. 3

2.4                          Mitigation Measures. 3

3....... Environmental Monitoring and Audit 4

3.1                          Implementation of Environmental Measures. 4

3.2                          Air Quality Monitoring Results. 4

3.3                          Noise Monitoring Results. 5

3.4                          Water Quality Monitoring Results. 5

3.5                          Dolphin Monitoring Results. 5

3.6                          Mudflat Monitoring Results. 15

3.7                          Solid and Liquid Waste Management Status. 26

3.8                          Environmental Licenses and Permits. 26

4....... Environmental Complaint and Non-compliance. 27

4.1                          Environmental Exceedances. 27

4.2                          Summary of Environmental Complaint, Notification of Summons and Successful Prosecution. 28

5....... Comments, Recommendations and Conclusion.. 30

5.1                          Comments. 30

5.2                          Recommendations. 31

5.3                          Conclusions. 31

 

 

 

 

 

 

 

 

 

Figures

 

Figure 1.1        Location of the Site

Figure 2.1         Environmental Monitoring Stations     

Figure 2.2         Transect Line Layout in Northwest and Northeast Lantau Survey Areas

 

                           

Appendices

 

Appendix A       Environmental Management Structure

Appendix B       Construction Programme

Appendix C       Location of Works Areas

Appendix D       Event and Action Plan  

Appendix E       Implementation Schedule of Environmental Mitigation Measures

Appendix F       Site Audit Findings and Corrective Actions

Appendix G      Air Quality Monitoring Data and Graphical Plots

Appendix H       Noise Monitoring Data and Graphical Plots

Appendix I         Water Quality Monitoring Data and Graphical Plots

Appendix J        Dolphin Monitoring Results

Appendix K       Waste Flow Table

Appendix L       Summary of Environmental Licenses and Permits

Appendix M      Record of ¡§Notification of Environmental Quality Limit Exceedances¡¨ and Record of ¡§Notification of Summons and Prosecutions¡¨

Appendix N       Cumulative Statistics on Complaints

Appendix O      Mudflat Monitoring Results


Executive Summary

The Hong Kong-Zhuhai-Macao Bridge (HZMB) Hong Kong Link Road (HKLR) serves to connect the HZMB Main Bridge at the Hong Kong Special Administrative Region (HKSAR) Boundary and the HZMB Hong Kong Boundary Crossing Facilities (HKBCF) located at the north eastern waters of the Hong Kong International Airport (HKIA).

The HKLR project has been separated into two contracts.  They are Contract No. HY/2011/03 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between Scenic Hill and Hong Kong Boundary Crossing Facilities (hereafter referred to as the Contract) and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between HKSAR Boundary and Scenic Hill.

China State Construction Engineering (Hong Kong) Ltd. was awarded by Highways Department as the Contractor to undertake the construction works of Contract No. HY/2011/03.  The main works of the Contract include land tunnel at Scenic Hill, tunnel underneath Airport Road and Airport Express Line, reclamation and tunnel to the east coast of the Airport Island, at-grade road connecting to the HKBCF and highway works of the HKBCF within the Airport Island and in the vicinity of the HKLR reclamation.  The Contract is part of the HKLR Project and HKBCF Project, these projects are considered to be ¡§Designated Projects¡¨, under Schedule 2 of the Environmental Impact Assessment (EIA) Ordinance (Cap 499) and EIA Reports (Register No. AEIAR-144/2009 and AEIAR-145/2009) were prepared for the Project.  The current Environmental Permit (EP) EP-352/2009/D for HKLR and EP-353/2009/K for HKBCF were issued on 22 December 2014 and 11 April 2016, respectively. These documents are available through the EIA Ordinance Register. The construction phase of Contract was commenced on 17 October 2012.

BMT Asia Pacific Limited has been appointed by the Contractor to implement the Environmental Monitoring & Audit (EM&A) programme for the Contract in accordance with the Updated EM&A Manual for HKLR (Version 1.0) and will be providing environmental team services to the Contract.

This is the thirteenth Quarterly EM&A report for the Contract which summarizes the monitoring results and audit findings of the EM&A programme during the reporting period from 1 September 2015 to 30 November 2015.

Environmental Monitoring and Audit Progress

The EM&A programme were undertaken in accordance with the Updated EM&A Manual for HKLR (Version 1.0).  A summary of the monitoring activities during this reporting period is presented as below:

Monitoring Activity

Monitoring Date

September 2015

October 2015

November 2015

Air Quality

1-hr TSP

2, 8, 14, 18, 24 and 30

6, 12, 16, 22 and 27

2, 6, 12, 18, 24 and 30

24-hr TSP

1, 7, 11, 17, 23 and 29

AMS5: 5, 9, 15, 20, 26 and 30

AMS6: 5, 9, 15, 20 and 26

AMS5: 5, 11, 17, 23 and 27

AMS6: 5, 11, 17 and 27

Noise

4, 8, 14, 24 and 30

6, 12, 22 and 27

2, 12, 18, 24 and 30

Water Quality

2, 4, 7, 9, 11, 14, 16, 18, 21, 23, 25, 28 and 30

2, 5, 7, 9, 12, 14, 16, 19, 21, 23, 26, 28 and 30

2, 4, 6, 9, 11, 13, 16, 18, 20, 23, 25, 27 and 30

Chinese White Dolphin

2, 11, 17 and 29

6, 13, 19 and 26

2, 6, 10 and 16

Mudflat Monitoring (Ecology)

5, 6, 10, 12 and 13

-

-

Mudflat Monitoring (Sedimentation rate)

10

-

-

Site Inspection

2, 9, 16, 25 and 30

7, 14, 22 and 30

4, 11, 18 and 27

 

 

 

Due to bad weather condition on 2 Sep 2015, noise monitoring at NMS5 was rescheduled from 2 Sep 2015 to 4 Sep 2015.

Due to boat availability issue, the dolphin monitoring schedule was rescheduled from 15 Sep 2015 to 17 Sep 2015, from 21 Sep 2015 to 29 Sep 2015 and from 9 October 2015 to 13 October 2015. 

Due to weather condition, the dolphin monitoring schedule was rescheduled from 5 October 2015 to 6 October 2015, from 23 October 2015 to 26 October 2015, from 5 November 2015 to 6 November 2015 and from 13 November 2015 to 16 November 2015. 

Due to malfunctioning of HVS at station AMS6, the 24-hr TSP monitoring at station AMS6 on 30 October 2015 was cancelled.

Due to power interruption at station AMS6 on 23 November 2015, the 24-hr TSP monitoring result obtained at AMS6 on 23 November 2015 was not completed and considered invalid.

Breaches of Action and Limit Levels

A summary of environmental exceedances for this reporting period is as follows:

Environmental Monitoring

Parameters

Action Level (AL)

Limit Level (LL)

Air Quality

1-hr TSP

0

0

24-hr TSP

0

0

Noise

Leq (30 min)

0

0

Water Quality

Suspended solids level (SS)

10

0

Turbidity level

0

0

Dissolved oxygen level (DO)

0

0

Dolphin Monitoring

Quarterly Analysis (Sep to Nov 2015)

2

0

The Environmental Team investigated all exceedances and found that they were not project related.

All investigation reports for exceedances of the Contract have been submitted to ENPO/IEC for comments and/or follow up to identify whether the exceedances occurred related to other HZMB contracts.

Implementation of Mitigation Measures

Site inspections were carried out on a weekly basis to monitor the implementation of proper environmental pollution control and mitigation measures for the Project.  Potential environmental impacts due to the construction activities were monitored and reviewed.

Complaint Log

There was one complaint received in relation to the environmental impact during the reporting period.

A summary of environmental complaints for this reporting period is as follows:

Environmental Complaint No.

Date of Complaint Received

Description of Environmental Complaints

COM-2015-079

7 December 2015

Water Quality

Notifications of Summons and Prosecutions

There were no notifications of summons or prosecutions received during this reporting period.


 

Reporting Changes

This report has been developed in compliance with the reporting requirements for the quarterly summary EM&A reports as required by the Updated EM&A Manual for HKLR (Version 1.0). 

The proposal for the change of Action Level and Limit Level for suspended solid and turbidity was approved by EPD on 25 March 2013.

The revised Event and Action Plan for dolphin monitoring was approved by EPD on 6 May 2013.

The original monitoring station at IS(Mf)9 (Coordinate- East:813273, North 818850) was observed inside the perimeter silt curtain of Contract HY/2010/02 on 1 July 2013, as such the original impact water quality monitoring location at IS(Mf)9 was temporarily shifted outside the silt curtain.  As advised by the Contractor of HY/2010/02 in August 2013, the perimeter silt curtain was shifted to facilitate safe anchorage zone of construction barges/vessels until end of 2013 subject to construction progress.  Therefore, water quality monitoring station IS(Mf)9 was shifted to 813226E and 818708N since 1 July 2013.  According to the water quality monitoring team¡¦s observation on 24 March 2014, the original monitoring location of IS(Mf)9 was no longer enclosed by the perimeter silt curtain of Contract HY/2010/02.  Thus, the impact water quality monitoring works at the original monitoring location of IS(Mf)9 has been resumed since 24 March 2014.

Transect lines 1, 2, 7, 8, 9 and 11 for dolphin monitoring have been revised due to the obstruction of the permanent structures associated with the construction works of HKLR and the southern viaduct of TM-CLKL, as well as provision of adequate buffer distance from the Airport Restricted Areas.  The EPD issued a memo and confirmed that they had no objection on the revised transect lines on 19 August 2015.

 


1        Introduction

1.1.1       The Hong Kong-Zhuhai-Macao Bridge (HZMB) Hong Kong Link Road (HKLR) serves to connect the HZMB Main Bridge at the Hong Kong Special Administrative Region (HKSAR) Boundary and the HZMB Hong Kong Boundary Crossing Facilities (HKBCF) located at the north eastern waters of the Hong Kong International Airport (HKIA).

1.1.2       The HKLR project has been separated into two contracts. They are Contract No. HY/2011/03 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between Scenic Hill and Hong Kong Boundary Crossing Facilities (hereafter referred to as the Contract) and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between HKSAR Boundary and Scenic Hill.

1.1.3       China State Construction Engineering (Hong Kong) Ltd. was awarded by Highways Department (HyD) as the Contractor to undertake the construction works of Contract No. HY/2011/03.  The Contract is part of the HKLR Project and HKBCF Project, these projects are considered to be ¡§Designated Projects¡¨, under Schedule 2 of the Environmental Impact Assessment (EIA) Ordinance (Cap 499) and EIA Reports (Register No. AEIAR-144/2009 and AEIAR-145/2009) were prepared for the Project.  The current Environmental Permit (EP) EP-352/2009/D for HKLR and EP-353/2009/K for HKBCF were issued on 22 December 2014 and 11 April 2016, respectively. These documents are available through the EIA Ordinance Register. The construction phase of Contract was commenced on 17 October 2012.  Figure 1.1 shows the project site boundary.

1.1.4       BMT Asia Pacific Limited has been appointed by the Contractor to implement the EM&A programme for the Contract in accordance with the Updated EM&A Manual for HKLR (Version 1.0) for HKLR and will be providing environmental team services to the Contract.  Ramboll  Environ Hong Kong Ltd. was employed by HyD as the Independent Environmental Checker (IEC) and Environmental Project Office (ENPO) for the Project. The project organization with regard to the environmental works is provided in Appendix A.

1.1.5       This is the thirteenth Quarterly Environmental Monitoring and Audit (EM&A) report for the Contract which summarizes the monitoring results and audit findings of the EM&A programme during the reporting period from 1 September 2015 to 30 November 2015.

1.2.1       The project organization structure and lines of communication with respect to the on-site environmental management structure with the key personnel contact names and numbers are shown in Appendix A. 

1.3                Construction Programme

1.3.1       A copy of the Contractor¡¦s construction programme is provided in Appendix B. 

1.4                Construction Works Undertaken During the Reporting Period

1.4.1       A summary of the construction activities undertaken during this reporting period is shown in Table 1.1.  The Works areas of the Contract are showed in Appendix C.

Table 1.1          Construction Activities during Reporting Period

Description of Activities

Site Area

Dismantling/trimming of temporary 40mm stone platform for construction of seawall

Portion X

Filling works behind stone platform

Portion X

Construction of seawall

Portion X

Loading and unloading of filling materials

Portion X

Band drains installation

Portion X

Excavation and lateral support works for Scenic Hill Tunnel (Cut & Cover Tunnel)

Portion X

Socket H-Piling work for Scenic Hill Tunnel (Cut & Cover Tunnel)

Portion X

Laying blinding layer for tunnel box structure at Scenic Hill Tunnel (Cut & Cover Tunnel)

Portion X

Construction of Sheet Pile at Scenic Hill Tunnel (Cut & Cover Tunnel)

Portion X

Construction of tunnel box structure at Scenic Hill Tunnel (Cut & Cover Tunnel)

Portion X

Pipe piling works for HKBCF to Airport Tunnel East (Cut & Cover Tunnel)

Portion X

Excavation for HKBCF to Airport Tunnel

Portion X

Sheet Piling Works for HKBCF to Airport Tunnel East (Cut & Cover Tunnel)

Portion X

Socket H-Piling Works for HKBCF to Airport Tunnel East (Cut &Cover Tunnel)

Portion X

Excavation for Scenic Hill Tunnel

West Portal

Ventilation building foundation and superstructure works

West Portal

Superstructure works for Scenic Hill Tunnel West Portal Ventilation building

West Portal

Pipe piling works for HKBCF to Airport Tunnel West (Cut & Cover Tunnel)

Airport Road

Works for diversion of Airport Road

Airport Road

Utilities detection

Airport Road/ Airport Express Line/ East Coast Road

Establishment of Site Access

Airport Road/ Airport Express Line/ East Coast Road

Canopy pipe drilling underneath Airport Express Line

Airport Express Line

Excavation and lateral support works at shaft 3 extension north shaft & south shaft

Kwo Lo Wan Road

Excavation and Lateral Support Works for HKBCF to Airport Tunnel West (Cut & Cover Tunnel)

Airport Road

Utility culvert excavation

Portion Y

Foundation works, sub-structure works and superstructure works for Highway Operation and Maintenance Area Building

Portion Y

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


2        EM&A Requirement

2.1                Summary of EM&A Requirements

2.1.1       The EM&A programme requires environmental monitoring of air quality, noise, water quality, dolphin monitoring and mudflat monitoring as specified in the approved EM&A Manual.

2.1.2       A summary of Impact EM&A requirements is presented in Table 2.1. The locations of air quality, noise and water quality monitoring stations are shown as in Figure 2.1.  The transect line layout in Northwest and Northeast Lantau Survey Areas is presented in Figure 2.2.

Table 2.1          Summary of Impact EM&A Requirements

Environmental Monitoring

Description

Monitoring Station

Frequencies

Remarks

Air Quality

1-hr TSP

AMS 5 & AMS 6

At least 3 times every 6 days

While the highest dust impact was expected.

24-hr TSP

At least once every 6 days

--

Noise

Leq (30mins),
L10
(30mins) and
L90
(30mins)

NMS5

At least once per week

Daytime on normal weekdays (0700-1900 hrs).

Water Quality

¡P    Depth

¡P    Temperature

¡P    Salinity

¡P    Dissolved Oxygen (DO)

¡P    Suspended Solids (SS)

¡P    DO Saturation

¡P    Turbidity

¡P    pH

¡P    Impact Stations:
IS5, IS(Mf)6, IS7, IS8, IS(Mf)9 & IS10,

¡P    Control/Far Field Stations:
CS2 & CS(Mf)5,

¡P    Sensitive Receiver Stations:
SR3, SR4, SR5, SR10A & SR10B

Three times per week during mid-ebb and mid-flood tides (within ¡Ó 1.75 hour of the predicted time)

3

(1 m below water surface, mid-depth and 1 m above sea bed, except where the water depth is less than 6 m, in which case the mid-depth station may be omitted.  Should the water depth be less than 3 m, only the mid-depth station will be monitored).

Dolphin

Line-transect Methods

Northeast Lantau survey area and Northwest Lantau survey area

Twice per month

--

Mudflat

Horseshoe crabs, seagrass beds, intertidal soft shore communities, sedimentation rates and water quality

San Tau and Tung Chung Bay

Once every 3 months

--

 

2.2.1       Table 2.2 presents the Action and Limit Levels for the 1-hour TSP, 24-hour TSP and noise level.

Table 2.2         Action and Limit Levels for 1-hour TSP, 24-hour TSP and Noise

Environmental Monitoring

Parameters

Monitoring Station

Action Level

Limit Level

Air Quality

1-hr TSP

AMS 5

352 µg/m3

500 µg/m3

AMS 6

360 µg/m3

24-hr TSP

AMS 5

164 µg/m3

260 µg/m3

AMS 6

173 µg/m3

Noise

Leq (30 min)

NMS 5

When one documented complaint is received

75 dB(A)

 

2.2.2       The Action and Limit Levels for water quality monitoring are given as in Table 2.3.

Table 2.3         Action and Limit Levels for Water Quality

Parameter (unit)

Water Depth

Action Level

Limit Level

Dissolved Oxygen (mg/L)

Surface and Middle

5.0

4.2 except 5 for Fish Culture Zone

Bottom

4.7

3.6

Turbidity (NTU)

Depth average

27.5 or 120% of upstream control station¡¦s turbidity at the same tide of the same day;

The action level has been amended to ¡§27.5 and 120% of upstream control station¡¦s turbidity at the same tide of the same day¡¨ since 25 March 2013.

47.0 or 130% of turbidity at the upstream control station at the same tide of same day;

The limit level has been amended to ¡§47.0 and 130% of turbidity at the upstream control station at the same tide of same day¡¨ since 25 March 2013.

Suspended Solid (SS) (mg/L)

Depth average

23.5 or 120% of upstream control station¡¦s SS at the same tide of the same day;

The action level has been amended to ¡§23.5 and 120% of upstream control station¡¦s SS at the same tide of the same day¡¨ since 25 March 2013.

34.4 or 130% of SS at the upstream control station at the same tide of same day and 10mg/L for Water Services Department Seawater Intakes;

The limit level has been amended to ¡§34.4 and 130% of SS at the upstream control station at the same tide of same day and 10mg/L for Water Services Department Seawater Intakes¡¨ since 25 March 2013

Notes:

               (1)    Depth-averaged is calculated by taking the arithmetic means of reading of all three depths.

               (2)    For DO, non-compliance of the water quality limit occurs when monitoring result is lower that the limit.

               (3)    For SS & turbidity non-compliance of the water quality limits occur when monitoring result is higher than the limits.

               (4)     The change to the Action and limit Levels for Water Quality Monitoring for the EM&A works was approved by EPD on 25 March 2013. Therefore, the amended Action and Limit Levels are applied for the water monitoring results obtained on and after 25 March 2013.

2.2.3       The Action and Limit Levels for dolphin monitoring are shown in Tables 2.4 and 2.5.

Table 2.4          Action and Limit Level for Dolphin Impact Monitoring

 

North Lantau Social Cluster

NEL

NWL

Action Level

STG < 70% of baseline &
ANI < 70% of baseline

STG < 70% of baseline &
ANI  < 70% of baseline

Limit Level

STG < 40% of baseline &
ANI < 40% of baseline

Remarks:

                 (1)        STG means quarterly average encounter rate of number of dolphin sightings.

                 (2)        ANI means quarterly average encounter rate of total number of dolphins.

                 (3)        For North Lantau Social Cluster, AL will be triggered if either NEL or NWL fall below the criteria; LL will be triggered if both NEL and NWL fall below the criteria.

Table 2.5          Derived Value of Action Level (AL) and Limit Level (LL)

 

North Lantau Social Cluster

NEL

NWL

Action Level

STG < 4.2  & ANI < 15.5

STG < 6.9 & ANI < 31.3

Limit Level

(STG < 2.4 & ANI < 8.9) and (STG < 3.9 & ANI < 17.9)

Remarks:

                 (1)        STG means quarterly average encounter rate of number of dolphin sightings.

                 (2)        ANI means quarterly average encounter rate of total number of dolphins.

                 (3)        For North Lantau Social Cluster, AL will be triggered if either NEL or NWL fall below the criteria; LL will be triggered if both NEL and NWL fall below the criteria.

 

2.3                Event Action Plans

2.3.1      The Event Actions Plans for air quality, noise, water quality and dolphin monitoring are annexed in Appendix D.

2.4                Mitigation Measures

2.4.1       Environmental mitigation measures for the contract were recommended in the approved EIA Report.  Appendix E lists the recommended mitigation measures and the implementation status. 


 

3        Environmental Monitoring and Audit

3.1                Implementation of Environmental Measures

3.1.1       In response to the site audit findings, the Contractor have rectified all observations identified in environmental site inspections undertaken during the reporting period. Details of site audit findings and the corrective actions during the reporting period are presented in Appendix F.

3.1.2       A summary of the Implementation Schedule of Environmental Mitigation Measures (EMIS) is presented in Appendix E. 

3.1.3       Regular marine travel route for marine vessels were implemented properly in accordance to the submitted plan and relevant records were kept properly.

3.1.4       Dolphin Watching Plan was implemented during the reporting period. No dolphins inside the silt curtain were observed. The relevant records were kept properly. 

3.2.1       The monitoring results for 1-hour TSP and 24-hour TSP are summarized in Tables 3.1 and 3.2 respectively. Detailed impact air quality monitoring results and relevant graphical plots are presented in Appendix G.

Table 3.1         Summary of 1-hour TSP Monitoring Results Obtained During the Reporting Period

Reporting Period

Monitoring

Station

Average (mg/m3)

Range (mg/m3)

Action Level (mg/m3)

Limit Level (mg/m3)

September 2015

AMS5

95

58 - 151

352

500

AMS6

97

66 - 138

360

October 2015

AMS5

123

87 - 204

352

AMS6

105

73 - 255

360

November 2015

AMS5

125

65 - 312

352

AMS6

127

78 - 316

360

 

 

 

 

 

 

 

 

 

 

 

Table 3.2         Summary of 24-hour TSP Monitoring Results Obtained During the Reporting Period

Reporting Period

Monitoring

Station

Average (mg/m3)

Range (mg/m3)

Action Level (mg/m3)

Limit Level (mg/m3)

September 2015

AMS5

36

18 - 77

164

260

AMS6

61

34 - 119

173

October 2015

AMS5

51

14 - 92

164

AMS6

80

27 - 136

173

November 2015

AMS5

55

37 - 71

164

AMS6

71

42 - 93

173

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.2.2       There were no Action and Limit Level exceedances of 1-hour TSP and 24-hour TSP were recorded at AMS5 and AMS6 during the reporting period.

3.3                Noise Monitoring Results

3.3.1       The monitoring results for construction noise are summarized in Table 3.3 and the monitoring results and relevant graphical plots for this reporting period are provided in Appendix H.

Table 3.3          Summary of Construction Noise Monitoring Results Obtained During the Reporting Period

Reporting period

Monitoring Station

Average Leq (30 mins), dB(A)*

Range of Leq (30 mins), dB(A)*

Action Level

Limit Level Leq (30 mins), dB(A)

September 2015

NMS5

56

55 ¡V 58

When one documented complaint is received

75

October 2015

58

58 ¡V 59

November 2015

60

58 ¡V 67

*A correction factor of +3dB(A) from free field to facade measurement was included. 

3.3.2       There were no Action and Limit Level exceedances for noise during daytime on normal weekdays of the reporting period.

3.3.3       Major noise sources during the noise monitoring included construction activities of the Contract and nearby traffic noise and insect noise.

3.4.1       Impact water quality monitoring was conducted at all designated monitoring stations during the reporting period. Impact water quality monitoring results and relevant graphical plots are provided in Appendix I.

3.4.2       During the reporting period, ten Action Level exceedances for suspended solid level were recorded. Record of ¡§Notification of Environmental Quality Limit Exceedances¡¨ is provided in Appendix M. No exceedance of Limit Level for suspended solid level was recorded. No exceedances of Action and Limit Level for dissolved oxygen level and turbidity were recorded.

3.4.3       Water quality impact sources during the water quality monitoring were the construction activities of the Contract, nearby construction activities by other parties and nearby operating vessels by other parties.

Data Analysis

3.5.1       Distribution Analysis ¡V The line-transect survey data was integrated with the Geographic Information System (GIS) in order to visualize and interpret different spatial and temporal patterns of dolphin distribution using sighting positions.  Location data of dolphin groups were plotted on map layers of Hong Kong using a desktop GIS (ArcView© 3.1) to examine their distribution patterns in details.  The dataset was also stratified into different subsets to examine distribution patterns of dolphin groups with different categories of group sizes, young calves and activities.

3.5.2       Encounter rate analysis ¡V Encounter rates of Chinese White Dolphins (number of on-effort sightings per 100 km of survey effort, and total number of dolphins sighted on-effort per 100 km of survey effort) were calculated in NEL and NWL survey areas in relation to the amount of survey effort conducted during each month of monitoring survey. Dolphin encounter rates were calculated in two ways for comparisons with the HZMB baseline monitoring results as well as to AFCD long-term marine mammal monitoring results. 

3.5.3       Firstly, for the comparison with the HZMB baseline monitoring results, the encounter rates were calculated using primary survey effort alone, and only data collected under Beaufort 3 or below condition would be used for encounter rate analysis.  The average encounter rate of sightings (STG) and average encounter rate of dolphins (ANI) were deduced based on the encounter rates from six events during the present quarter (i.e. six sets of line-transect surveys in North Lantau), which was also compared with the one deduced from the six events during the baseline period (i.e. six sets of line-transect surveys in North Lantau). 

3.5.4       Secondly, the encounter rates were calculated using both primary and secondary survey effort collected under Beaufort 3 or below condition as in AFCD long-term monitoring study.  The encounter rate of sightings and dolphins were deduced by dividing the total number of on-effort sightings and total number of dolphins (ANI) by the amount of survey effort for the present quarterly period.

3.5.5       Quantitative grid analysis on habitat use ¡V To conduct quantitative grid analysis of habitat use, positions of on-effort sightings of Chinese White Dolphins collected during the quarterly impact phase monitoring period were plotted onto 1-km2 grids among Northwest Lantau (NWL) and Northeast (NEL) survey areas on GIS.  Sighting densities (number of on-effort sightings per km2) and dolphin densities (total number of dolphins from on-effort sightings per km2) were then calculated for each 1 km by 1 km grid with the aid of GIS.  Sighting density grids and dolphin density grids were then further normalized with the amount of survey effort conducted within each grid.  The total amount of survey effort spent on each grid was calculated by examining the survey coverage on each line-transect survey to determine how many times the grid was surveyed during the study period.  For example, when the survey boat traversed through a specific grid 50 times, 50 units of survey effort were counted for that grid.  With the amount of survey effort calculated for each grid, the sighting density and dolphin density of each grid were then normalized (i.e. divided by the unit of survey effort). 

3.5.6       The newly-derived unit for sighting density was termed SPSE, representing the number of on-effort sightings per 100 units of survey effort.  In addition, the derived unit for actual dolphin density was termed DPSE, representing the number of dolphins per 100 units of survey effort.  Among the 1-km2 grids that were partially covered by land, the percentage of sea area was calculated using GIS tools, and their SPSE and DPSE values were adjusted accordingly.  The following formulae were used to estimate SPSE and DPSE in each 1-km2 grid within the study area:

SPSE = ((S / E) x 100) / SA%

DPSE = ((D / E) x 100) / SA%

 

where        S = total number of on-effort sightings

D = total number of dolphins from on-effort sightings

E = total number of units of survey effort

SA% = percentage of sea area

3.5.7       Behavioural analysis ¡V When dolphins were sighted during vessel surveys, their behaviour was observed.  Different activities were categorized (i.e. feeding, milling/resting, traveling, socializing) and recorded on sighting datasheets.  This data was then input into a separate database with sighting information, which can be used to determine the distribution of behavioural data with a desktop GIS.  Distribution of sightings of dolphins engaged in different activities and behaviours would then be plotted on GIS and carefully examined to identify important areas for different activities of the dolphins. 

3.5.8       Ranging pattern analysis ¡V Location data of individual dolphins that occurred during the 3-month baseline monitoring period were obtained from the dolphin sighting database and photo-identification catalogue.  To deduce home ranges for individual dolphins using the fixed kernel methods, the program Animal Movement Analyst Extension, was loaded as an extension with ArcView© 3.1 along with another extension Spatial Analyst 2.0.  Using the fixed kernel method, the program calculated kernel density estimates based on all sighting positions, and provided an active interface to display kernel density plots.  The kernel estimator then calculated and displayed the overall ranging area at 95% UD level.

Summary of Survey Effort and Dolphin Sightings

3.5.9       During the period of September to November 2015, six sets of systematic line-transect vessel surveys were conducted to cover all transect lines in NWL and NEL survey areas twice per month.

3.5.10    From these surveys, a total of 902.25 km of survey effort was collected, with 95.0% of the total survey effort being conducted under favourable weather conditions (i.e. Beaufort Sea State 3 or below with good visibility).  Among the two areas, 346.64 km and 555.61 km of survey effort were conducted in NEL and NWL survey areas respectively. 

3.5.11    The total survey effort conducted on primary lines 656.41 km, while the effort on secondary lines was 245.84 km.  Survey effort conducted on both primary and secondary lines were considered as on-effort survey data.  A summary table of the survey effort is shown in Annex I of Appendix J.

3.5.12    During the six sets of monitoring surveys in September-November 2015, a total of 18 groups of 95 Chinese White Dolphins were sighted.  A summary table of the dolphin sightings is shown in Annex II of Appendix J.

3.5.13    For the present quarterly period, all dolphin sightings were made during on-effort search, and all except one dolphin sighting were made on primary lines.  Moreover, all dolphin groups were sighted in NWL, while none was sighted at all in NEL.  In fact, since July 2014, only one sighting of a lone dolphin was made in NEL during HKLR03 monitoring surveys.

Distribution

3.5.14    Distribution of dolphin sightings made during monitoring surveys in September to November 2015 is shown in Figure 1 of Appendix J. Dolphin sightings made in the present quarter were mostly clustered around Lung Kwu Chau (Figure 1 of Appendix J).  A few other sightings were also made near Sha Chau and to the west of the airport platform (Figure 1 of Appendix J).

3.5.15    Notably, all dolphin sightings were made far away from the HKLR03/HKBCF reclamation sites as well as along the entire alignment of Tuen Mun-Chek Lap Kok Link (TMCLKL) during the present quarterly period (Figure 1 of Appendix J). On the other hand, two sightings with five dolphins were made in the vicinity of the HKLR09 alignment (Figure 1 of Appendix J).

3.5.16    Sighting distribution of the present impact phase monitoring period (September to November 2015) was compared to the one during the baseline monitoring period (September to November 2011).  In the present quarter, dolphins have disappeared from the NEL region, which was in stark contrast to their frequent occurrence around the Brothers Islands, near Shum Shui Kok and in the vicinity of HKBCF reclamation site during the baseline period (Figure 1 of Appendix J). The nearly complete abandonment of NEL region by the dolphins has been consistently recorded in the past eleven quarters of HKLR03 monitoring, which has resulted in zero to extremely low dolphin encounter rate in this area.

3.5.17    In NWL survey area, dolphin occurrence was also drastically different between the baseline and impact phase periods.  During the present impact monitoring period, fewer dolphins occurred in this survey area than during the baseline period, when many of the dolphin sightings were concentrated between Lung Kwu Chau and Black Point, around Sha Chau, near Pillar Point and to the west of the Chek Lap Kok Airport (Figure 1 of Appendix J). 

3.5.18    Another comparison in dolphin distribution was made between the three quarterly periods of autumn months in 2013, 2014 and 2015 (Figure 2 of Appendix J). Among the three autumn periods, no dolphin was sighted at all in NEL in both 2014 and 2015, while two sightings were made there in 2013 (Figure 2 of Appendix J).

3.5.19    On the other hand, dramatic changes in dolphin distribution in NWL waters were also observed in the autunm months during the three-year period (Figure 2 of Appendix J).  In 2013, dolphins regularly occurred throughout the NWL survey area, with higher concentrations of sightings around Sha Chau, Lung Kwu Chau, near Black Point and Pillar Point.  In 2014, dolphins still frequently occurred around Sha Chau and Lung Kwu Chau, but less frequently in the middle portion of the North Lantau region.  In 2015, they infrequently occurred in NWL survey area with the only concentration of sightings around Lung Kwu Chau, while they generally absent for the rest of this area.  Similar temporal changes in dolphin distribution were also observed in the spring and summer periods of 2013-15.  The temporal trend indicated that dolphin usage in the NWL region has progressively diminished in recent years.

Encounter Rate

3.5.20    During the present three-month study period, the encounter rates of Chinese White Dolphins deduced from the survey effort and on-effort sighting data from the primary transect lines under favourable conditions (Beaufort 3 or below) for each set of the surveys in NEL and NWL are shown in Table 3.4.  The average encounter rates deduced from the six sets of surveys were also compared with the ones deduced from the baseline monitoring period (September ¡V November 2011) (See Table 3.5).

Table 3.4         Dolphin Encounter Rates (Sightings Per 100 km of Survey Effort) During Reporting Period (September to November 2015) 

Survey Area

Dolphin Monitoring

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 surve
y effort)

Primary Lines Only

Primary Lines Only

Northeast  Lantau

Set 1 (2 & 11 Sep 2015)

0.00

0.00

Set 2 (17 & 29 Sep 2015)

0.00

0.00

Set 3 (6 & 13 Oct 2015)

0.00

0.00

Set 4 (19 & 26 Oct 2015)

0.00

0.00

Set 5 (2 & 6 Nov 2015)

0.00

0.00

Set 6 (10 & 16 Nov 2015)

0.00

0.00

Northwest Lantau

Set 1 (2 & 11 Sep 2015)

5.47

51.95

Set 2 (17 & 29 Sep 2015)

4.01

21.38

Set 3 (6 & 13 Oct 2015)

5.86

24.91

Set 4 (19 & 26 Oct 2015)

2.73

10.94

Set 5 (2 & 6 Nov 2015)

3.84

15.38

Set 6 (10 & 16 Nov 2015)

1.73

1.73


 

Table 3.5     Comparison of average dolphin encounter rates from impact monitoring period (September to November 2015) and baseline monitoring period (September ¡V November 2011)

Survey Area

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)

Reporting Period

Baseline Monitoring Period

Reporting Period

Baseline Monitoring Period

Northeast Lantau

0.0

6.00 ¡Ó 5.05

0.0

22.19 ¡Ó 26.81

Northwest Lantau

3.94 ¡Ó 1.57

9.85 ¡Ó 5.85

21.05 ¡Ó 17.19

44.66 ¡Ó 29.85

Notes:
1) The encounter rates deduced from the baseline monitoring period have been recalculated based only on the survey effort and on-effort sighting data made along the primary transect lines under favourable conditions.

2) ¡Ó denotes the standard deviation of the average encounter rates.

 

3.5.21    To facilitate the comparison with the AFCD long-term monitoring results, the encounter rates were also calculated for the present quarter using both primary and secondary survey effort.  The encounter rates of sightings (STG) and dolphins (ANI) in NWL were 3.31 sightings and 17.52 dolphins per 100 km of survey effort respectively, while the encounter rates of sightings (STG) and dolphins (ANI) in NEL were both nil for this quarter.

3.5.22    In NEL, the average dolphin encounter rates (both STG and ANI) in the present three-month impact monitoring period were zero with no sighting made, and such low occurrence of dolphins in NEL have been consistently recorded in the past eleven quarters of HKLR03 monitoring (Table 3.6). This is a serious concern as the dolphin occurrence in NEL in the last eleven quarters (0.0-1.0 for ER(STG) and 0.0-3.9 for ER(ANI)) have been exceptionally low when compared to the baseline period (Table 3.6).  Dolphins have almost vacated from NEL waters since January 2014, with only two groups of five dolphins sighted there since then despite consistent and intensive survey effort being conducted in this survey area. 

Table 3.6     Comparison of Average Dolphin Encounter Rates in Northeast Lantau Survey Area from All Quarters of Impact Monitoring Period and Baseline Monitoring Period (Sep ¡V Nov 2011)

Monitoring Period

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)

September-November 2011 (Baseline)

6.00 ¡Ó 5.05

22.19 ¡Ó 26.81

December 2012-February 2013 (Impact)

3.14 ¡Ó 3.21

6.33 ¡Ó 8.64

March-May 2013 (Impact)

0.42 ¡Ó 1.03

0.42 ¡Ó 1.03

June-August 2013 (Impact)

0.88 ¡Ó 1.36

3.91 ¡Ó 8.36

September-November 2013 (Impact)

1.01 ¡Ó 1.59

3.77 ¡Ó 6.49

December 2013-February 2014 (Impact)

0.45 ¡Ó 1.10

1.34 ¡Ó 3.29

March-May 2014 (Impact)

0.00

0.00

June-August 2014 (Impact)

0.42 ¡Ó 1.04

1.69 ¡Ó 4.15

September-November 2014 (Impact)

0.00

0.00

December 2014-February 2015 (Impact)

0.00

0.00

March-May 2015 (Impact)

0.00

0.00

June ¡V August 2015 (Impact)

0.44 ¡Ó 1.08

0.44 ¡Ó 1.08

September-November 2015 (Impact)

0.00

0.00

Notes:
1) The encounter rates deduced from the baseline monitoring period have been recalculated based only on survey effort and on-effort sighting data made along the primary transect lines under favourable conditions.

2) ¡Ó denotes the standard deviation of the average encounter rates.

 

3.5.23    Moreover, the average dolphin encounter rates (STG and ANI) in NWL during the present impact phase monitoring period were also much lower (reductions of 60.0% and 52.9% respectively) than the ones recorded in the 3-month baseline period, indicating a dramatic decline in dolphin usage of this survey area as well during the present impact phase period (Table 3.7). 

3.5.24    Even for the same autumn quarters, the dolphin encounter rates in NWL during autumn 2015 were much lower than the ones recorded in autumn 2013 and 2014 (Table 3.7).

3.5.25    It should be noted that the encounter rates in NWL in the present quarter have slightly rebounded from the exceptionally low level in the previous three quarters (Table 3.7).  Such potential rebound in dolphin occurrence could be an encouraging sign, and should be continuously monitored in the upcoming monitoring quarters.

Table 3.7        Comparison of Average Dolphin Encounter Rates in Northwest Lantau Survey Area from All Quarters of Impact Monitoring Period and Baseline Monitoring Period (Sep ¡V Nov 2011)

Monitoring Period

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)

September-November 2011 (Baseline)

9.85 ¡Ó 5.85

44.66 ¡Ó 29.85

December 2012-February 2013 (Impact)

8.36 ¡Ó 5.03

35.90 ¡Ó 23.10

March-May 2013 (Impact)

7.75 ¡Ó 3.96

24.23 ¡Ó 18.05

June-August 2013 (Impact)

6.56 ¡Ó 3.68

27.00 ¡Ó 18.71

September-November 2013 (Impact)

8.04 ¡Ó 1.10

32.48 ¡Ó 26.51

December 2013-February 2014 (Impact)

8.21 ¡Ó 2.21

32.58 ¡Ó 11.21

March-May 2014 (Impact)

6.51 ¡Ó 3.34

19.14 ¡Ó 7.19

June-August 2014 (Impact)

4.74 ¡Ó 3.84

17.52 ¡Ó 15.12

September-November 2014 (Impact)

5.10 ¡Ó 4.40

20.52 ¡Ó 15.10

December 2014-February 2015 (Impact)

2.91 ¡Ó 2.69

11.27 ¡Ó 15.19

March-May 2015 (Impact)

0.47 ¡Ó 0.73

2.36 ¡Ó 4.07

June ¡V August 2015 (Impact)

2.53 ¡Ó 3.20

9.21 ¡Ó 11.57

September-November 2015 (Impact)

3.94 ¡Ó 1.57

21.05 ¡Ó 17.19

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Notes:

1) The encounter rates deduced from the baseline monitoring period have been recalculated based only on survey effort and on-effort sighting data made along the primary transect lines under favourable conditions.

2) ¡Ó denotes the standard deviation of the average encounter rates.

 

3.5.26    As discussed recently in Hung (2015), the dramatic decline in dolphin usage of NEL waters in the past few years (including the declines in abundance, encounter rate and habitat use in NEL, as well as shifts of individual core areas and ranges away from NEL waters) was possibly related to the HZMB construction works that were commenced since 2012.  It appeared that such noticeable decline has already extended to NWL waters progressively in 2013 to 2015.

3.5.27    A two-way ANOVA with repeated measures and unequal sample size was conducted to examine whether there were any significant differences in the average encounter rates between the baseline and impact monitoring periods.  The two variables that were examined included the two periods (baseline and impact phases) and two locations (NEL and NWL). 

3.5.28    For the comparison between the baseline period and the present quarter (twelfth quarter of the impact phase being assessed), the p-values for the differences in average dolphin encounter rates of STG and ANI were 0.0079 and 0.071 respectively.  If the alpha value is set at 0.05, significant differences were detected between the baseline and present quarters in the dolphin encounter rate of STG, but not in the dolphin encounter rate of ANI.

3.5.29    For the comparison between the baseline period and the cumulative quarters in impact phase (i.e first twelve quarters of the impact phase being assessed), the p-values for the differences in average dolphin encounter rates of STG and ANI were 0.00009 and 0.00003 respectively.  Even if the alpha value is set at 0.0001, significant differences were still detected in both the average dolphin encounter rates of STG and ANI (i.e. between the two periods and the locations).

3.5.30    As indicated in both dolphin distribution patterns and encounter rates, dolphin usage has been significantly reduced in both NEL and NWL survey areas during the present quarterly period, and such low occurrence of dolphins has also been consistently documented in previous quarters. This raises serious concern, as the timing of the decline in dolphin usage in North Lantau waters coincided well with the construction schedule of the HZMB-related projects (Hung 2015).

3.5.31    To ensure the continuous usage of North Lantau waters by the dolphins, every possible measure should be implemented by the contractors and relevant authorities of HZMB-related works to minimize all disturbances to the dolphins.

Group Size

3.5.32    Group size of Chinese White Dolphins ranged from one to twelve individuals per group in North Lantau region during September to November 2015.  The average dolphin group sizes from these three months were compared with the ones deduced from the baseline period in September to November 2011, as shown in Table 3.8.


 

Table 3.8         Comparison of Average Dolphin Group Sizes between Reporting Period (Sep ¡V Nov 2015) and Baseline Monitoring Period (Sep ¡V Nov 2011)

Survey Area

Average Dolphin Group Size

Reporting Period

Baseline Monitoring Period

Overall

5.28 ¡Ó 3.54 (n = 18)

3.72 ¡Ó 3.13 (n = 66)

Northeast Lantau

N/A

3.18 ¡Ó 2.16 (n = 17)

Northwest Lantau

5.28 ¡Ó 3.54 (n = 18)

3.92 ¡Ó 3.40 (n = 49)

 

 

 

 

 

 

 

 

 

 

 

Note:

1)       ¡Ó denotes the standard deviation of the average group size.

3.5.33    The average dolphin group sizes in NWL waters during September to November 2015 was higher than the ones recorded during the three-month baseline period (Table 3.8). Seven of the 18 groups were composed of 1-3 individuals only, while five other groups were moderate in size with 4-6 individuals per group.  Moreover, six large dolphin groups were sighted during the present quarterly period, including three groups with 7-9 individuals each, and another three groups with 10-12 individuals each.

3.5.34    Distribution of dolphins with larger group sizes (five individuals or more per group and ten individuals per group) during the present quarter is shown in Figure 3 of Appendix J, with comparison to the one in baseline period.  During the autumn months of 2015, distribution of these large groups of dolphins were all located around Lung Kwu Chau and Sha Chau, with the three exceptionally large groups of dolphins (i.e. with 10 or more individuals) sighted adjacent to Lung Kwu Chau (Figure 3 of Appendix J). This distribution pattern was very different from the baseline period, when the larger dolphin groups were distributed more evenly in NWL waters with a few more sighted in NEL waters (Figure 3 of Appendix J).

Habitat Use

3.5.35    From September to November 2015, the only area being heavily utilized by Chinese White Dolphins was around and to the north of Lung Kwu Chau, as well as both eastern and western sides of Sha Chau in North Lantau region (Figures 4a and 4b of Appendix J). All grids near HKLR03/HKBCF reclamation sites as well as TMCLKL alignment did not record any presence of dolphins during on-effort search in the present quarterly period, but one grid (F19) in the vicinity of HKLR09 alignment recorded moderately high dolphin densities (Figures 4b of Appendix J).

3.5.36    It should be emphasized that the amount of survey effort collected in each grid during the three-month period was fairly low (6-12 units of survey effort for most grids), and therefore the habitat use pattern derived from the three-month dataset should be treated with caution.  A more complete picture of dolphin habitat use pattern should be examined when more survey effort for each grid will be collected throughout the impact phase monitoring programme.

3.5.37    When compared with the habitat use patterns during the baseline period, dolphin usage in NEL and NWL has dramatically diminished in both areas during the present impact monitoring period (Figure 5 of Appendix J).  During the baseline period, many grids between Siu Mo To and Shum Shui Kok recorded moderately high to high dolphin densities, which was in stark contrast to the complete absence of dolphins there during the present impact phase period (Figure 5 of Appendix J). 

3.5.38    The density patterns were also very different in NWL between the baseline and impact phase monitoring periods, with higher dolphin usage around Sha Chau, near Black Point, to the west of the airport, as well as between Pillar Point and airport platform during the baseline period.  In contrast, only the waters around Lung Kwu Chau and Sha Chau recorded high densities of dolphins during the present impact phase period (Figure 5 of Appendix J). 

Mother-calf Pairs

3.5.39    During the present quarterly period, two young calves (i.e. unspotted calf or unspotted juvenile) were spotted with their mothers near Lung Kwu Chau

3.5.40    The rare occurrence of young calves in the present quarter was in stark contrast to their regular occurrence in North Lantau waters during the baseline period.  This should be of a serious concern, and the occurrence of young calves in North Lantau waters should be closely monitored in the upcoming quarters.

Activities and Associations with Fishing Boats

3.5.41    Four of the 18 dolphin groups were engaged in feeding activities, while two other dolphin groups were engaged in socializing activities.  None of the dolphin groups were engaged in traveling or milling/resting activity during the three-month study period.

3.5.42    The percentages of sightings associated with feeding activities (22.2%) and socializing activities (11.1%) during the present impact phase period were both higher than the ones recorded during the baseline period (11.6% and 5.4% respectively).  However, it should be noted the sample sizes on total numbers of dolphin sightings were very different between the two periods

3.5.43    Distribution of dolphins engaged in various activities during the present three-month period and baseline period is shown in Figure 6 of Appendix J.  The four dolphin groups engaged in feeding activities were sighted near Lung Kwu Chau and Sha Chau as well as to the north of Lung Kwu Chau (Figure 6 of Appendix J).  The two groups engaged in socializing activities were both located to the west of Lung Kwu Chau (Figure 6 of Appendix J).

3.5.44    When compared to the baseline period, distribution of various dolphin activities during the present impact phase monitoring period was drastically different with a much more restricted area of occurrences.

3.5.45    As consistently recorded in the past monitoring quarters, none of the 18 dolphin groups was found to be associated with operating fishing vessels in North Lantau waters during the present impact phase period.

Summary Photo-identification works

3.5.46    From September to November 2015, over 2,500 digital photographs of Chinese White Dolphins were taken during the impact phase monitoring surveys for the photo-identification work.

3.5.47    In total, 34 individuals sighted 65 times altogether were identified (see summary table in Annex III of Appendix J and photographs of identified individuals in Annex IV of Appendix J).  All of these re-sightings were made in NWL.

3.5.48    The majority of identified individuals were sighted only once or twice during the three-month period, with the exception of two individuals (NL46 and NL210) being 3-4 times and another three individuals (NL48, NL202 and NL286) being sighted 5-6 times.

3.5.49    Notably, eight of these 34 individuals (NL33, NL123, NL284, NL285, WL05, WL79, WL241 and WL243) were also sighted in West Lantau waters during the HKLR09 monitoring surveys from September to November 2015, implying that they have moved across the HKLR09 bridge alignment during the same three-month period.

Individual range use

3.5.50    Ranging patterns of the 34 individuals identified during the three-month study period were determined by fixed kernel method, and are shown in Annex V of Appendix J.

3.5.51    All identified dolphins sighted in the present quarter were utilizing NWL waters only, but have completely avoided NEL waters where many of them have utilized as their core areas in the past Annex V of Appendix J).  This is in contrary to the extensive movements between NEL and NWL survey areas observed in the earlier impact monitoring quarters as well as the baseline period.

3.5.52    Notably, several individuals (NL33, NL123, NL284, NL285 and WL05) consistently utilized both NWL and NEL waters in the past have extended their range use to WL waters (and even SWL waters in the case of NL33) during the present quarter.  In the upcoming quarters, individual range use and movements should be continuously monitored to examine whether there has been any consistent shifts of individual home ranges from North Lantau to West or Southwest Lantau, as such shift could possibly be related to the HZMB-related construction works (see Hung 2015).

Action Level / Limit Level Exceedance

3.5.53    There was two Action Level exceedances of dolphin monitoring for the quarterly monitoring data (between September - November 2015).  According to the contractor¡¦s information, the marine activities undertaken for HKLR03 during the quarter of September to November 2015 included reclamation, excavation of stone platform, construction of seawall, temporary drainage diversion and ground investigation. There is no evidence showing the current AL non-compliance directly related to the construction works of HKLR03 (where the amounts of working vessels for HKLR03 have been decreasing), although the generally increased amount of vessel traffic in NEL since the impact phase (October 2012). It should also be noted that reclamation work under HKLR03 (adjoining the Airport Island) situates in waters which has rarely been used by dolphins in the past, and the working vessels under HKLR03 have been travelling from source to destination in accordance with the Marine Travel Route to minimize impacts on Chinese White Dolphin.  In addition, the contractor will implement proactive mitigation measures such as avoiding anchoring at Marine Department¡¦s designated anchorage site ¡V Sham Shui Kok Anchorage (near Brothers Island) as far as practicable. 

3.5.54    A two-way ANOVA with repeated measures and unequal sample size was conducted to examine whether there were any significant differences in the average encounter rates between the baseline and impact monitoring periods.  The two variables that were examined included the two periods (baseline and impact phases) and two locations (NEL and NWL).A).

3.5.55    For the comparison between the baseline period and the present quarter (12th quarter of the impact phase being assessed), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.0079 and 0.071 respectively.  If the alpha value is set at 0.05, significant differences were detected between the baseline and present quarters in dolphin encounter rate of STG, but not in the dolphin encounter rate of ANI.

3.5.56    For the comparison between the baseline period and the cumulative quarters in impact phase (i.e. first twelve quarters of the impact phase being assessed), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.00009 and 0.00003 respectively.  Even if the alpha value is set at 0.001, significant differences were detected in both the average dolphin encounter rates of STG and ANI (i.e. between the two periods and the locations).

3.5.57    The AFCD monitoring data during September 2015 to November 2015 has been reviewed by the dolphin specialist.  During the same quarter, no dolphin was sighted from 78.70 km of survey effort on primary lines in NEL, while seven groups of 24 dolphins were sighted from 144.11 km of survey effort on primary lines in NWL.  This review has confirmed that the low occurrence of dolphins reported by the HKLR03 monitoring surveys in autumn 2015 in NEL and NWL survey area is accurate.

3.5.58    All dolphin protective measures are fully and properly implemented in accordance with the EM&A Manual. According to the Marine Travel Route Plan, if vessels are crossing along edge of the proposed marine park, the travelling speed will keep not exceeding 5 knots when crossing the edge of the proposed marine park. The Contractor will continue to provide training for skippers to ensure that their working vessels travel from source to destination to minimize impacts on Chinese White Dolphin and avoid anchoring at Marine Department¡¦s designated anchorage site - Sham Shui Kok Anchorage (near Brothers Island) as far as practicable. Also, it is recommended to complete the marine works of the Contract as soon as possible so as to reduce the overall duration of impacts and allow the dolphins population to recover as early as possible.

3.5.59    A meeting was held on 15 January 2016 with attendance of representative of Highways Department (HyD), ENPO, Resident Site Staff (RSS), Environmental Team (ET) and dolphin specialist for Contract Nos. HY/2010/02, HY/2011/03, HY/2012/07, HY/2012/08. Also, main Contractor for Contract Nos. HY/2012/07 and HY/2012/08 attended the meeting. The discussion/recommendation as recorded in the minutes of the meeting, which might be relevant to HKLR03 Contract are summarized below.

3.5.60    It was concluded that the HZMB works is one of the contributing factors affecting the dolphins. It was also concluded the contribution of impacts due to the HZMB works as a whole (or individual marine contracts) cannot be quantified nor separate from the other stress factors.

3.5.61    It was reminded that the ETs shall keep reviewing the implementation status of the dolphin related mitigation measures and remind the contractor to ensure the relevant measures were fully implemented.

3.5.62    It was recommended that the marine works of HZMB projects should be completed as soon as possible so as to reduce the overall duration of impacts and allow the dolphins population to recover as early as possible.

3.5.63    It was also recommended that the marine works footprint (e.g., reduce the size of peripheral silt curtain) and vessels for the marine works should be reduced as much as possible, and vessels idling / mooring in other part of the North Lantau shall be avoided whenever possible.

3.5.64    It was suggested that the protection measures (e.g., speed limit control) for the proposed Brothers Island Marine Park (BMP) shall be brought forward as soon as possible before its establishment so as to provide a better habitat for dolphin recovery. It was noted that under the Regular Marine Travel Route Plan, the contractors have committed to reduce the vessel speed in BMP. HyD updated that the proposed BMP will be gazetted in January 2016. The ETs were reminded to update the BMP boundary in the Regular Marine Travel Route Plan.

3.5.65    There was a discussion on exploring possible further mitigation measures, for example, controlling the underwater noise. It was noted that the EIA reports for the projects suggested several mitigation measures, all of which have been implemented.

3.6                Mudflat Monitoring Results

Sedimentation Rate Monitoring

3.6.1       The baseline sedimentation rate monitoring was in September 2012 and impact sedimentation rate monitoring was undertaken on 10 September 2015. The mudflat surface levels at the four established monitoring stations and the corresponding XYZ HK1980 GRID coordinates are presented in Table 3.9 and Table 3.10.

Table 3.9          Measured Mudflat Surface Level Results

Baseline Monitoring
(September 2012)

Impact Monitoring
(
September 2015)

Monitoring Station

Easting
(m)

Northing (m)

Surface Level
(mPD)

Easting
(m)

Northing (m)

Surface Level

(mPD)

S1

810291.160

816678.727

0.950

810291.167

816678.723

1.061

S2

810958.272

815831.531

0.864

810958.278

815831.542

0.960

S3

810716.585

815953.308

1.341

810716.595

815953.340

1.466

S4

811221.433

816151.381

0.931

811221.414

816151.336

1.004

Table 3.10       Comparison of Measurement  

Comparison of measurement

Remarks and Recommendation

Monitoring Station

Easting
(m)

Northing (m)

Surface Level
(mPD)

S1

0.007

-0.004

0.111

Level continuously increased

S2

0.006

0.011

0.096

Level continuously increased

S3

0.010

0.032

0.125

Level continuously increased

S4

-0.019

-0.045

0.073

Level continuously increased

 

3.6.2       This measurement result was generally and relatively higher than the baseline measurement at S1, S2, S3 and S4. The mudflat level is continuously increased.

Water Quality Monitoring

3.6.3       The mudflat monitoring covered water quality monitoring data.  Reference was made to the water quality monitoring data of the representative water quality monitoring station (i.e. SR3) as in the EM&A Manual.  The water quality monitoring location (SR3) is shown in Figure 2.1. 

3.6.4       Impact water quality monitoring in San Tau (monitoring station SR3) was conducted in September 2015. The monitoring parameters included dissolved oxygen (DO), turbidity and suspended solids (SS).

3.6.5       The Impact monitoring result for SR3 were extracted and summarised below:

Table 3.11       Impact Water Quality Monitoring Results (Depth Average)

Date

Mid Ebb Tide

Mid Flood Tide

DO (mg/L)

Turbidity (NTU)

SS (mg/L)

DO (mg/L)

Turbidity (NTU)

SS (mg/L)

2-Sep-15

5.69

20.40

8.30

5.46

15.85

13.50

4-Sep-15

6.27

7.55

7.35

6.22

4.40

4.60

7-Sep-15

6.32

3.75

3.30

6.43

4.75

5.80

9-Sep-15

6.89

4.65

2.95

7.75

4.80

4.10

11-Sep-15

6.53

5.95

5.35

9.00

7.20

6.80

14-Sep-15

5.82

6.75

6.50

5.74

5.35

7.00

16-Sep-15

5.86

10.70

11.90

5.64

7.50

7.70

18-Sep-15

5.82

8.50

7.50

5.71

6.70

6.20

21-Sep-15

6.07

6.30

5.30

6.58

3.80

2.70

23-Sep-15

6.15

3.80

2.45

7.39

3.30

2.60

25-Sep-15

6.63

5.20

5.90

8.23

10.05

5.20

28-Sep-15

5.27

7.65

7.90

6.04

8.05

8.55

30-Sep-15

5.64

17.15

13.75

5.47

12.45

16.00

Average

6.07

8.33

6.80

6.59

7.25

6.98

Mudflat Ecology Monitoring

Sampling Zone

3.6.6       In order to collect baseline information of mudflats in the study site, the study site was divided into three sampling zones (labeled as TC1, TC2, TC3) in Tung Chung Bay and one zone in San Tau (labeled as ST) (Figure 2.1 of Appendix O). The horizontal length of sampling zones TC1, TC2, TC3 and ST were about 250 m, 300 m, 300 m and 250 m, respectively. Survey of horseshoe crabs, seagrass beds and intertidal communities were conducted in every sampling zone. The present survey was conducted in September 2015 (totally 5 sampling days between 5th and 13th September 2015The locations of sampling zones are shown in Annex I of Appendix O. 

Horseshoe Crabs

3.6.7       Active search method was conducted for horseshoe crab monitoring by two experienced surveyors at every sampling zone. During the search period, any accessible and potential area would be investigated for any horseshoe crab individuals within 2-3 hours in low tide period (tidal level below 1.2 m above Chart Datum (C.D.)). Once a horseshoe crab individual was found, the species was identified referencing to Li (2008). The prosomal width, inhabiting substratum and respective GPS coordinate were recorded. A photographic record was taken for future investigation. Any grouping behavior of individuals, if found, was recorded. The horseshoe crab surveys were conducted on 6th (for TC1), 10th (for TC3 and ST) and 12th (for TC2) September 2015. During the survey period, the weather was hot and sunny in TC1, TC3 and ST while it was rainy in TC2.

Seagrass Beds

3.6.8       Active search method was conducted for seagrass bed monitoring by two experienced surveyors at every sampling zone. During the search period, any accessible and potential area would be investigated for any seagrass beds within 2-3 hours in low tide period. Once seagrass bed was found, the species, estimated area, estimated coverage percentage and respective GPS coordinate were recorded. A photographic record was taken for future investigation. The seagrass beds surveys were conducted on 6th (for TC1), 10th (for TC3 and ST) and 12th (for TC2) September 2015. During the survey period, the weather was hot and sunny in TC1, TC3 and ST while it was rainy in TC2.

Intertidal Soft Shore Communities

3.6.9       The intertidal soft shore community surveys were conducted in low tide period on 5th (for ST), 6th (for TC1), 12th (for TC2) and 13th September 2015 (for TC3). At each sampling zone, three 100 m horizontal transects were laid at high tidal level (H: 2.0 m above C.D.), mid tidal level (M: 1.5 m above C.D.) and low tidal level (L: 1.0 m above C.D.). Along every horizontal transect, ten random quadrats (0.5 m x 0.5m) were placed.

3.6.10    Inside a quadrat, any visible epifauna were collected and were in-situ identified to the lowest practical taxonomical resolution. Whenever possible a hand core sample (10 cm internal diameter ´ 20 cm depth) of sediments was collected in the quadrat. The core sample was gently washed through a sieve of mesh size 2.0 mm in-situ. Any visible infauna were collected and identified. Finally the top 5 cm surface sediments were dug for visible infauna in the quadrat regardless of hand core sample was taken.

3.6.11    All collected fauna were released after recording except some tiny individuals that are too small to be identified on site. These tiny individuals were taken to laboratory for identification under dissecting microscope.

3.6.12    The taxonomic classification was conducted in accordance to the following references: Polychaetes: Fauchald (1977), Yang and Sun (1988); Arthropods: Dai and Yang (1991), Dong (1991); Mollusks: Chan and Caley (2003), Qi (2004).

Data Analysis

3.6.13    Data collected from direct search and core sampling was pooled in every quadrat for data analysis. Shannon-Weaver Diversity Index (H¡¦) and Pielou¡¦s Species Evenness (J) were calculated for every quadrat using the formulae below,

H¡¦= -£U ( Ni / N ) ln ( Ni / N ) (Shannon and Weaver, 1963)

J = H¡¦ / ln S, (Pielou, 1966)

 

where S is the total number of species in the sample, N is the total number of individuals, and Ni is the number of individuals of the ith species.

Mudflat Ecology Monitoring Results and Conclusion

Horseshoe Crabs

3.6.14    In general, two species of horseshoe crab Carcinoscorpius rotundicauda (total 196 ind.) and Tachypleus tridentatus (total 10 ind.) were recorded in the survey area. Individuals were mainly found on fine sand while few were found on soft mud. The group size varied from 2 to 26 individuals for every sight record. Although less number of Tachypleus tridentatus was recorded, the average body size was larger than that of Carcinoscorpius rotundicauda. Photo records were shown in Figure 3.1 of Appendix O while the complete records of horseshoe crab survey in every sampling zone were shown in Annex II of Appendix O.

3.6.15    One big individual of Carcinoscorpius rotundicauda was found trapped in a trash fish net (Figure 3.1 of Appendix O) on ST shore (GPS coordinate: 22¢X 17.385' N, 113¢X 55.460' E). Its prosomal width reached 130.77 mm. After photo recording, it was released to water. This big individual should have had migrated to sub-tidal habitat. It might forage on intertidal habitat occasionally during high tide period. Since intertidal soft shore was no longer a nursery ground for this individual, its record was excluded from the data analysis. It was to avoid mixing up with juvenile population living on soft shore.

3.6.16    Table 3.1 of Appendix O summarizes the survey results of horseshoe crab in present survey. For Carcinoscorpius rotundicauda, it could be found in all sampling zones while more individuals were recorded in TC3 and ST (TC1: 41 ind., TC2: 4 ind., TC3: 70 ind., ST: 81 ind.). The search record was 10.3 ind. hr-1 person-1, 1.0 ind. hr-1 person-1, 11.7 ind. hr-1 person-1, 13.5 ind. hr-1 person-1 in TC1, TC2, TC3 and ST respectively. The size of individuals was similar among TC1 (mean prosomal width: 39.58 mm), TC2 (36.20 mm) and ST (37.03mm) while that of TC3 was smaller (27.27 mm).

3.6.17    For Tachypleus tridentatus, it could be found in TC3 (1 ind.) and ST (9 ind.) only. The search records were 0.2 ind. hr-1 person-1 and 1.5 ind. hr-1 person-1 in TC3 and ST respectively. The mean prosomal width of TC3 (53.90 mm) was larger than that of ST (48.50mm).

3.6.18    In the previous survey of March 2015, there was one important finding that a mating pair of Carcinoscorpius rotundicauda was found in ST (prosomal width: male 155.1 mm, female 138.2 mm) (Figure 3.2 of Appendix O). It indicated the importance of ST as a breeding ground of horseshoe crab. Moreover, two moults of Carcinoscorpius rotundicauda were found in TC1 with similar prosomal width 130-140 mm (Figure 3.2 of Appendix O). It reflected that a certain numbers of moderately sized individuals inhabited the sub-tidal habitat of Tung Chung Wan after its nursery period on soft shore. These individuals might move onto soft shore during high tide for feeding, moulting and breeding. Then it would return to sub-tidal habitat during low tide. Because the mating pair should be inhabiting sub-tidal habitat in most of the time. The record was excluded from the data analysis to avoid mixing up with juvenile population living on soft shore.

3.6.19    No marked individual of horseshoe crab was recorded in present survey. Some marked individuals were found in previous surveys conducted in September 2013, March 2014 and September 2014. All of them were released through a conservation programme conducted by Prof. Paul Shin (Department of Biology and Chemistry, The City University of Hong Kong (CityU)). It was a re-introduction trial of artificial bred horseshoe crab juvenile at selected sites. So that the horseshoe crabs population might be restored in the natural habitat. Through a personal conversation with Prof. Shin, about 100 individuals were released in the sampling zone ST on 20 June 2013. All of them were marked with color tape and internal chip detected by specific chip sensor. There should be second round of release between June and September 2014 since new marked individuals were found in the survey of September 2014.

3.6.20    The artificial bred individuals, if found, would be excluded from the results of present monitoring programme in order to reflect the changes of natural population. However, the mark on their prosoma might have been detached during moulting after a certain period of release. The artificially released individuals were no longer distinguishable from the natural population without the specific chip sensor. The survey data collected would possibly cover both natural population and artificially bred individuals.

Population difference among the sampling zones

3.6.21    Figures 3.3 and 3.4 of Appendix O show the changes of number of individuals, mean prosomal width and search record of horseshoe crabs Carcinoscorpius rotundicauda and Tachypleus tridentatus respectively in every sampling zone along the sampling months. In general, higher search records (i.e. number of individuals) of both species were always found in ST followed by TC3 from September 2012 to September 2014. Then the search record in TC3 was even higher than that in ST from March 2015 to June 2015. In this sampling month (Sep. 2015), highest search record was found in ST again. For TC1, the search record was at low to medium level and fluctuated slightly along the sampling months. In contrast, much lower search record was found in TC2 (2 ind. in September 2013, 1 ind. in March, June, September. 2014, March and June 2015, 4 ind. in September. 2015). For spatial difference of horseshoe crab size, larger individuals were usually found in ST while smaller individuals were usually found in TC3.

3.6.22    Throughout the monitoring period conducted, it was obvious that TC3 and