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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. 11 (Mar 2015 to May 2015)

 

31 August 2015

 

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 3

2.1                    Summary of EM&A Requirements. 3

2.2                    Action and Limit Levels. 4

2.3                    Event Action Plans. 5

2.4                    Mitigation Measures. 5

3....... Environmental Monitoring and Audit 6

3.1                    Implementation of Environmental Measures. 6

3.2                    Air Quality Monitoring Results. 6

3.3                    Noise Monitoring Results. 7

3.4                    Water Quality Monitoring Results. 7

3.5                    Dolphin Monitoring Results. 7

3.6                    Mudflat Monitoring Results. 17

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/H for HKBCF were issued on 22 December 2014 and 19 January 2015, 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 eleventh 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 March 2015 to 31 May 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

March 2015

April 2015

May 2015

Air Quality

1-hr TSP

2, 6, 12, 18, 24 and 30

2, 8, 14, 20, 24 and 29

5, 11, 15, 21 and 27

24-hr TSP

5, 11, 17, 23 and 27

1, 8, 13, 17, 23 and 28

AMS5: 4, 8, 14, 20 and 26

AMS6: 4, 12, 15, 20 and 26

Noise

2, 12, 18, 24 and 30

8, 14, 20 and 29

5, 11, 21 and 27

Water Quality

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

1, 3, 6, 8, 10, 13, 15, 17, 20, 22, 24, 27 and 29

1, 4, 6, 8, 11, 13, 15, 18, 20, 22, 25, 27 and 29

Chinese White Dolphin

4, 11, 17 and 26

8, 10, 17 and 22

4, 8, 14 and 18

Mudflat Monitoring (Ecology)

7, 8, 10, 20, 21 and 22

-

-

Mudflat Monitoring (Sedimentation rate)

20

-

-

Site Inspection

4, 11, 18 and 27

1, 8, 15, 22 and 30

6, 13, 20 and 29

 

 

 

Due to change of tide pattern and weather condition, mudflat monitoring (ecology) was rescheduled from 24 March to 20 March 2015.

Due to malfunction of HVS at AMS6 on 8 May 2015, the 24-hr TSP monitoring result obtained on 8 May 2015 was considered invalid. The 24-hr TSP monitoring was rescheduled from 8 May to 12 May 2015.

Due to power interruption of HVS at station AMS6 on 14 May 2015, the 24-hr TSP monitoring at station AMS6 was rescheduled from 14 May 2015 to 15 May 2015.

Due to change of weather condition on 21 May 2015, the dolphin monitoring was rescheduled from 21 May 2015 to 18 May 2015.

Due to boat availability issue, the dolphins monitoring was rescheduled from 9 March 2015 to 11 March 2015, from 23 March 2015 to 26 March 2015, from 14 April 2015 to 10 April 2015 and from 11 May 2015 to 8 May 2015.

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

1

1

24-hr TSP

0

0

Noise

Leq (30 min)

0

0

Water Quality

Suspended solids level (SS)

4

0

Turbidity level

0

0

Dissolved oxygen level (DO)

0

0

Dolphin Monitoring

Quarterly Analysis (Mar to May 2015)

0

1

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 were two environmental complaints 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-2015-066

8 April 2015

Air Quality

COM-2015-068

10 April 2015

Noise


 

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.


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/H for HKBCF were issued on 22 December 2014 and 19 January 2015, 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.  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 eleventh 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 March 2015 to 31 May 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

Site Area

Description of Activities

Portion X

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

Portion X

Filling works behind stone platform

Portion X

Temporary stone platform construction

Portion X

Sheet piling

Portion X

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

Portion X

Sheet Piling Work for Scenic Hill Tunnel (Cut & Cover Tunnel)

Portion X

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

Portion X

Construction of Seawall

Portion X

Loading and unloading of filling materials

Portion X

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

Portion X

Excavation works for HKBCF to Airport Tunnel

West Portal

Pipe roofing installation and excavation for  Scenic Hill Tunnel

West Portal

Ventilation Building Foundation Works

West Portal

Excavation for Scenic Hill Tunnel

Kwo Lo Wan / Airport Road

Works for diversion of Airport Road and Kwo Lo Wan Road

Airport Road

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

Airport Road

Mini-piling work for  HKBCF to Airport Tunnel West (Cut & Cover Tunnel)

Airport Road

Pipe Piling Cofferdam Works for  HKBCF to Airport Tunnel West (Cut & Cover Tunnel)

Airport Road

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

Airport Express Line

Pre-grouting and pipe piling works for Airport Express Line access shafts

Airport Express Line

Canopy pipe drilling underneath Airport Express Line

Kwo Lo Wan/ Airport Road/ Airport Express Line

Utilities detection

Airport Road/ Airport Express Line/ East Coast Road

Establishment of Site Access

Kwo Lo Wan Road

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

Portion Y

Utility culvert excavation

Portion Y

Highway Operation and Maintenance Area Building  Foundation Works

 


 

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

·    Depth

·    Temperature

·    Salinity

·    Dissolved Oxygen (DO)

·    Suspended Solids (SS)

·    DO Saturation

·    Turbidity

·    pH

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

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

·    Sensitive Receiver Stations:
SR3, SR4, SR5, SR10A & SR10B

Three times per week during mid-ebb and mid-flood tides (within ± 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 most of the observations as identified during environmental site inspection during the reporting period. Follow-up actions for outstanding observations will be inspected during the next 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 During the Reporting Period

Reporting Period

Monitoring

Station

Average (mg/m3)

Range (mg/m3)

Action Level (mg/m3)

Limit Level (mg/m3)

March 2015

AMS5

151

69 - 508

352

500

AMS6

115

65 - 173

360

April 2015

AMS5

99

67 - 176

352

AMS6

93

65 - 150

360

May 2015

AMS5

69

59 – 83

352

AMS6

75

63 - 107

360

 

 

 

 

 

 

 

 

 

 

 

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

Reporting Period

Monitoring

Station

Average (mg/m3)

Range (mg/m3)

Action Level (mg/m3)

Limit Level (mg/m3)

March 2015

AMS5

60

32 - 103

164

260

AMS6

75

42 - 112

173

April 2015

AMS5

48

31 - 101

164

AMS6

67

36 - 118

173

May 2015

AMS5

21

14 - 27

164

AMS6

43

22 - 64

173

 

 

 

 

 

 

 

 

 

 

3.2.2       An Action Level exceedance and a Limit Level exceedance of 1-hr TSP level at AMS5 were recorded during the reporting period. No Action Level exceedances of 24-hr TSP level at AMS5 were recorded during the reporting period.

3.2.3       No Action and Limit Level exceedances of 1-hour TSP and 24-hour TSP were recorded at 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 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)

March 2015

NMS5

59

57 - 60

When one documented complaint is received

75

April 2015

61

58 - 63

May 2015

63

56 – 74

*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.

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, four Action Level exceedances for suspended solid level were recorded. 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 – 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 – 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 entire quarterly period (March – May 2015).

3.5.5       Quantitative grid analysis on habitat use – 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 – 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 – 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 March to May 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 899.81 km of survey effort was collected, with 97.7% 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, 344.55 km and 555.26 km of survey effort were conducted in NEL and NWL survey areas respectively. 

3.5.11    The total survey effort conducted on primary lines was 655.32 km, while the effort on secondary lines was 244.49 km.  Both survey effort conducted on 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 March to May 2015, a total of 7 groups of 25 Chinese White Dolphins were sighted.  Four of the seven dolphin sightings were made during on-effort search.  Two of the four on-effort sightings were made on primary lines, while the other two were made on secondary lines.  In this quarterly period, all dolphin groups were sighted in NWL, while none of them were sighted in NEL.  In fact, no dolphin was sighted in NEL since July 2014, and only one group of four dolphins was sighted there since December 2013 during HKLR03 monitoring surveys. A summary table of the dolphin sightings is shown in Annex II of Appendix J.

Distribution

3.5.13    Distribution of dolphin sightings made during monitoring surveys in March to May 2015 is shown in Figure 1 of Appendix J. These sightings made in the present quarter were scattered to the western end of the NWL survey area, with no particular concentration (Figure 1 of Appendix J).  No dolphin was sighted at all in NEL survey area.

3.5.14    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 this quarterly period (Figure 1 of Appendix J). However, one sighting of a lone individual was made adjacent to the HKLR09 alignment (Figure 1 of Appendix J).

3.5.15    Sighting distribution of the present impact phase monitoring period (March to May 2015) was compared to the one during the baseline monitoring period (September to November 2011).  In the present quarter, dolphins have completely avoided 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 nine quarters, which have resulted in extremely low to zero dolphin encounter rate in this area.

3.5.16    In NWL survey area, dolphin occurrence was also drastically different between the baseline and impact phase quarters.  During the present impact monitoring period, much fewer dolphins occurred throughout 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). 

3.5.17    Another comparison in dolphin distribution was made between the three quarterly periods of spring months in 2013, 2014 and 2015 (Figure 2 of Appendix J). Among the three spring periods, no dolphin sighting was made in NEL in 2014 and 2015, while there were a few sightings made there in 2012 (Figure 2 of Appendix J). The near absence of dolphins in this quarter in NEL was probably more related to the seasonal occurrence that has been consistently recorded in the past.

3.5.18    On the other hand, dramatic changes in dolphin distribution in NWL waters have observed in the spring months during the three-year period.  In 2013, dolphin regularly occurred throughout the NWL survey area, with higher concentration around Sha Chau and Lung Kwu Chau as well as near Black Point.  In 2014, dolphin still occurred around Lung Kwu Chau at a high level, but less frequently in the middle portion of North Lantau region.  In 2014, they rarely occurred in NWL survey area with scattered sightings without any particular concentration.  The temporal trend indicated that dolphin usage in the NWL region has greatly diminished during the spring months of the past few years.

Encounter Rate

3.5.19    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 – November 2011) (See Table 3.5).

Table 3.4         Dolphin Encounter Rates (Sightings Per 100 km of Survey Effort) During Reporting Period (March to May 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 (4 & 11 Mar 2015)

0.00

0.00

Set 2 (17 & 26 Mar 2015)

0.00

0.00

Set 3 (8 & 10 Apr 2015)

0.00

0.00

Set 4 (17 & 22 Apr 2015)

0.00

0.00

Set 5 (4 & 8 May 2015)

0.00

0.00

Set 6 (14 & 18 May 2015)

0.00

0.00

Northwest Lantau

Set 1 (4 & 11 Mar 2015)

1.42

9.93

Set 2 (17 & 26 Mar 2015)

0.00

0.00

Set 3 (8 & 10 Apr 2015)

1.40

4.20

Set 4 (17 & 22 Apr 2015)

0.00

0.00

Set 5 (4 & 8 May 2015)

0.00

0.00

Set 6 (14 & 18 May 2015)

0.00

0.00

Table 3.5     Comparison of average dolphin encounter rates from impact monitoring period (March to May 2015) and baseline monitoring period (September – 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

0.00

6.00 ± 5.05

0.00

22.19 ± 26.81

Northwest Lantau

0.47 ± 0.73

9.85 ± 5.85

2.36 ± 4.07

44.66 ± 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) ± denotes the standard deviation of the average encounter rates.

3.5.20    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 0.75 sightings and 3.91 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.

3.5.21    In NEL, the average dolphin encounter rates (both STG and ANI) in the present three-month impact monitoring period were zero, and such low occurrence of dolphins in NEL have been consistently recorded in the past nine quarters (Table 3.6). It is a serious concern that dolphin occurrence in NEL in the nine 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 one group of four dolphins sighted since then. 

3.5.22    Moreover, the average dolphin encounter rates (STG and ANI) in NWL during the present impact phase monitoring period were also much lower (reductions of 95.2% and 94.7% respectively) than the ones recorded in the 3-month baseline period, indicating a dramatic decline in dolphin usage of this survey area during the present impact phase period (Table 3.7). 

3.5.23    Even within the same spring quarters, the dolphin encounter rates in NWL during spring 2015 were small fractions of the ones recorded in spring (March –May) 2013 and (March – May) 2014 (Table 3.7).

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 – 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 ± 5.05

22.19 ± 26.81

December 2012-February 2013 (Impact)

3.14 ± 3.21

6.33 ± 8.64

March-May 2013 (Impact)

0.42 ± 1.03

0.42 ± 1.03

June-August 2013 (Impact)

0.88 ± 1.36

3.91 ± 8.36

September-November 2013 (Impact)

1.01 ± 1.59

3.77 ± 6.49

December 2013-February 2014 (Impact)

0.45 ± 1.10

1.34 ± 3.29

March-May 2014 (Impact)

0.00

0.00

June-August 2014 (Impact)

0.42 ± 1.04

1.69 ± 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

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) ± denotes the standard deviation of the average encounter rates.

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 – 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 ± 5.85

44.66 ± 29.85

December 2012-February 2013 (Impact)

8.36 ± 5.03

35.90 ± 23.10

March-May 2013 (Impact)

7.75 ± 3.96

24.23 ± 18.05

June-August 2013 (Impact)

6.56 ± 3.68

27.00 ± 18.71

September-November 2013 (Impact)

8.04 ± 1.10

32.48 ± 26.51

December 2013-February 2014 (Impact)

8.21 ± 2.21

32.58 ± 11.21

March-May 2014 (Impact)

6.51 ± 3.34

19.14 ± 7.19

June-August 2014 (Impact)

4.74 ± 3.84

17.52 ± 15.12

September-November 2014 (Impact)

5.10 ± 4.40

20.52 ± 15.10

December 2014-February 2015 (Impact)

2.91 ± 2.69

11.27 ± 15.19

March-May 2015 (Impact)

0.47 ± 0.73

2.36 ± 4.07

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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) ± denotes the standard deviation of the average encounter rates.

3.5.24    Notably, the first eight consecutive quarters have triggered the Action Levels under the Event and Action Plan, while the previous and present quarters have both triggered the Limit Levels.  As discussed recently in Hung (2014), the dramatic decline in dolphin usage of NEL waters in 2012 and 2013 (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 in 2012.  It appeared that such noticeable decline has already extended to NWL waters progressively in 2013 and 2014.

3.5.25    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). 

3.5.26    For the comparison between the baseline period and the present quarter (tenth quarter of the impact phase being assessed), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.0015 and 0.0139 respectively.  If the alpha value is set at 0.05, significant difference was detected between the baseline and present quarters in both dolphin encounter rates of STG and ANI.

3.5.27    For the comparison between the baseline period and the cumulative quarters in impact phase (i.e. first ten quarters of the impact phase being assessed), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.0004 and 0.0001 respectively.  Even if the alpha value is set at 0.01, significant differences were detected in both the average dolphin encounter rates of STG and ANI (i.e. between the two periods and the locations).

3.5.28    As indicated in both dolphin distribution patterns and encounter rates, dolphin usage has been significantly reduced in NEL and NWL waters in the present quarterly period, and such low occurrence has been consistently documented in previous quarters.  This raises serious concern, as the decline in dolphin usage in North Lantau waters could possibly link to the HZMB-related construction activities.

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

Group Size

3.5.30    Group size of Chinese White Dolphins ranged from one to eight individuals per group in North Lantau region during March to May 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 (March to May 2015) and Baseline Monitoring Period (Sep– Nov 2011)

Survey Area

Average Dolphin Group Size

Reporting Period

Baseline Monitoring Period

Overall