Highway Logo2.jpg

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.3 (March 2013 to May 2013)

 

2 September 2013

 

Revision 4

 

 

 

 

 

 

 

 

 

 

 

 

 

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. 14

3.7                          Solid and Liquid Waste Management Status. 20

3.8                          Environmental Licenses and Permits. 20

4....... Environmental Complaint and Non-compliance. 21

4.1                          Environmental Exceedances. 21

4.2                          Summary of Environmental Complaint, Notification of Summons and Successful Prosecution. 24

5....... COMMENTS, RECOMMENDATIONS AND CONCLUSION.. 25

5.1                          Comments. 25

5.2                          Recommendations. 26

5.3                          Conclusions. 27

 

 

 

 

 

 

 

 

 

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

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 Environmental Impact Assessment (EIA) Reports (Register No. AEIAR-144/2009 and AEIAR-145/2009) were prepared for the Project.  The current Environmental Permit (EP) EP-352/2009/A for HKLR and EP-353/2009/F for HKBCF were issued on 31 October 2011 and 24 April 2013, 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 third Quarterly EM&A report for the Contract which summaries the monitoring results and audit findings of the EM&A programme during the reporting period from 1 March 2013 to 31 May 2013.

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 2013

April 2013

May 2013

Air Quality

1-hr TSP

4, 8, 14, 20 and 26

3, 9, 15, 19 and 25

AMS5: 2, 7, 13, 16, 22 and 28

 AMS6: 2, 7, 13, 16, 24 and 28

24-hr TSP

1, 7, 13, 19 and 25

2, 8, 12, 18, 24 and 30

AMS5: 6, 10, 15, 28 and 31

AMS6: 6, 10, 15, 21, 27 and 31

Noise

4, 14, 20 and 26

3, 9, 19 and 25

2, 7, 13, 22 and 28

Water Quality

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

1, 3, 5, 8, 10, 12, 15, 17, 19, 22, 24, 26 and 29

1, 3, 6, 8, 10, 13, 15, 17, 20, 22, 24, 27, 29 and 31

Chinese White Dolphin

6, 11, 13 and 20

2, 3, 8 and 12

8, 13, 25 and 28

Mudflat Monitoring

2, 3, 10, 11, 12 and 16

-

-

Site Inspection

5, 12, 19 and 26

2, 9, 17, 26 and 30

7, 14, 21 and 31

Due to adverse weather condition, the water monitoring for mid-ebb tide were cancelled on 5 and 19 April 2013 and 22 May 2013. 

The high volume sampler (HVS) for AMS5 was out of order on 21 May 2013 and the 24-hr dust monitoring at AMS5 was cancelled on 21 May 2013.  The HVS was repaired on 27 May 2013 and the 24-hr dust monitoring was postponed to 28 May 2013.

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)

4

0

Water Quality

Suspended solids level (SS)

16

87

Turbidity level

8

78

Dissolved oxygen level (DO)

0

0

Dolphin

Ecology (Chinese White Dolphin Monitoring)

1

0

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

There was one Action Level exceedance of dolphin monitoring for the quarterly monitoring data (March – May 2013).

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

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

Environmental Complaint No. (1)

Date of Complaint Received

Description of Environmental Complaints

COM-2013-018

1 March 2013

Noise

COM-2013-022

8 April 2013

Water

COM-2013-018 (6), (7) & (9)

15 April 2013

Noise

COM-2013-018 (11)

30 April 2013

Noise

COM-2013-023

2 May 2013

Noise

COM-2013-024

23 May 2013

Noise

COM-2013-022(2)

23 May 2013

Water

Remarks:

(1) If a complainant makes complaint for the same environmental issue, only one complaint number will be assigned for the complaint. 

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).  There are no reporting changes.


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 Environmental Impact Assessment (EIA) Reports (Register No. AEIAR-144/2009 and AEIAR-145/2009) were prepared for the Project.  The current Environmental Permit (EP) EP-352/2009/A for HKLR and EP-353/2009/F for HKBCF were issued on 31 October 2011 and 24 April 2013, 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 Third Quarterly Environmental Monitoring and Audit (EM&A) report for the Contract which summaries the monitoring results and audit findings of the EM&A programme during the reporting period from 1 March 2013 to 31 May 2013.

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 Y

Access Shaft Construction for SHT & HAT

Utility culvert excavation

Portion X

Removal of existing rock for existing seawall

Stone Column installation

Sand filling behind stone platform in according to EP requirement

Temporary stone platform construction

Band Drains Installation

Kwo Lo Wan Road/ Airport Road

Works for diversion of Airport Road and Kwo Lo Wan Road

Kwo Lo Wan/ Airport Road/ AEL

Pre-grouting and pipe piling works for AEL access shafts

Utilities detection

Establishment of site access

Works for East access shaft

West Portal

Site formation

Tree Felling

Slope protection/ stabilization (soil nailing works)

Boulder removal/ stabilization works

 


 

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

·    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 trigger 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 trigger 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 Contractors carried out corrective actions.  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 were observed.  The relevant records were kept properly. 

3.1.5       A dolphin exclusion zone of 250m was implemented during the installation of silt curtains on 2, 3, 6, 9, 13, 15 and 18 May 2013.  No dolphins 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 2013

AMS5

53

1598

352

500

AMS6

62

13 133

360

April 2013

AMS5

93

35215

352

AMS6

3.2.2       84

3.2.3       17 205

360

May 2013

AMS5

26

765

352

AMS6

24

15 43

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 2013

AMS5

55

28 90

164

260

AMS6

58

22 105

173

April 2013

AMS5

57

22 103

164

AMS6

60

25 108

173

May 2013

AMS5

23

9 58

164

AMS6

26

17 51

173

 

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 2013

NMS5

59

5561

When one documented complaint is received

75

April 2013

60

5960

May 2013

62

5868

*+3dB(A) Facade correction included

3.3.2       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       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 (STG) and total number of dolphins (ANI) by the amount of survey effort for the entire quarterly period (March-May 2013).

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 reporting period, 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 887.74 km of survey effort was collected, with 89.5% 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, 340.62 km and 547.12 km of survey effort were conducted in NEL and NWL survey areas respectively.  In addition, the total survey effort conducted on primary lines was 660.79 km, while the effort on secondary lines was 226.95 km.  Survey effort conducted on primary and secondary lines were both considered as on-effort survey data. 

3.5.11    During the six sets of monitoring surveys in March to May 2013, a total of 39 groups of 127 Chinese White Dolphins were sighted.  All except two sightings were made during on-effort search.  Thirty-two on-effort sightings were made on primary lines, while another five on-effort sightings were made on secondary lines.  Among the two survey areas, only two groups of two dolphins were sighted in NEL, while the other 37 groups of 125 dolphins were sighted in NWL. 

Distribution

3.5.12    Distribution of dolphin sightings made during monitoring surveys in March April and May 2013 was shown in Figure 1 of Appendix J.  Most dolphins sightings were made in the northwest portion of North Lantau region, concentrating along the Urmston Road section between Black Point and Lung Kwu Chau.  Other sightings were made around Sha Chau, between Pillar Point and the airport platform, as well as to the west of the airport platform.  The two lone dolphins sighted in NEL were found near Tai Mo To and Yam O.

3.5.13    No dolphin was sighted in the vicinity of the HKLR03 reclamation site (Figure 1 of Appendix J). The lone dolphin sighted near Tai Mo To was in the vicinity of the HKBCF reclamation site, but dolphins generally were absent from the surrounding waters of the reclamation area. On the other hand, a few dolphin sightings were made near the HKLR09 alignment to the west of the airport platform (Figure 1 of Appendix J).

3.5.14    When compared with the sighting distribution of dolphins during baseline monitoring surveys in September to November 2011, dolphins very rarely occurred in NEL region during the present impact monitoring period, in contrast with their frequent occurrence around the Brothers Islands and HKBCF reclamation site during the baseline period (Figure 1 of Appendix J). However, dolphin occurrence in the northwest portion of North Lantau region was similar between the two periods (Figure 1 of Appendix J).

Encounter Rate

3.5.15    For the three-month study period in March, April and May 2013,  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) from each of the survey areas 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 in September to November 2011 (See Table 3.5).

Table 3.4         Dolphin Encounter Rates (Sightings Per 100 km of Survey Effort) During three Reporting Period (March 2013 – May 2013) 

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 (6 & 11 Mar 2013)

0.00

0.00

Set 2 (13 & 20 Mar 2013)

2.53

2.53

Set 3 (2 & 3 Apr 2013)

0.00

0.00

Set 4 (8 & 12 Apr 2013)

0.00

0.00

Set 5 (8 & 13 May 2013)

0.00

0.00

Set 6 (25 & 28 May 2013)

0.00

0.00

Northwest Lantau

Set 1 (6 & 11 Mar 2013)

9.57

33.49

Set 2 (13 & 20 Mar 2013)

13.82

49.76

Set 3 (2 & 3 Apr 2013)

4.38

10.94

Set 4 (8 & 12 Apr 2013)

4.16

5.54

Set 5 (8 & 13 May 2013)

9.88

36.24

Set 6 (25 & 28 May 2013)

4.69

9.39

 

Table 3.5         Comparison of Average Dolphin Encounter Rates between Reporting Period (March 2013 – May 2013) and Baseline Monitoring Period (Sep– Nov 2011) (Note: 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)

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

0.42 ± 1.03

6.00 ± 5.05

0.42 ± 1.03

22.19 ± 26.81

Northwest Lantau

7.75 ± 3.96

9.85 ± 5.85

24.23 ± 18.05

44.66 ± 29.85

 

3.5.16    In NEL, the average dolphin encounter rates (both STG and ANI) in the present three-month study period were close to nil, which was much lower than the ones recorded in the 3-month baseline period (Table 3.5).  It should be noted that dolphin occurrence in NEL was generally lower in spring months (March-May), and hence it is noteworthy to determine whether the recorded occurrence of dolphins in the habitat of NEL during this impact phase monitoring period was due to seasonal fluctuation. For example, the encounter rates deduced from the advance HZMB monitoring data in spring 2011 were 5.4 (STG) and 11.8 (ANI) respectively. By pooling both HZMB and AFCD monitoring data, the encounter rates in spring 2011 were 3.8 (STG) and 13.3 (ANI) respectively.

3.5.17    In NWL, the average dolphin encounter rates (STG and ANI) during the present impact phase monitoring period were also noticeably lower (reductions of 21% and 46% respectively) than the ones recorded in the 3-month baseline period, indicating a reduced dolphin usage of this survey area.

3.5.18    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).

3.5.19    For the comparison between the baseline period and the present quarter (third quarter of the impact phase), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.0858 and 0.0931 respectively, and therefore no significant difference is detected based on the alpha value of 0.05.

3.5.20    For the comparison between the baseline period and the cumulative quarters in impact phase (i.e. first three quarters of the impact phase), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.1336 and 0.0507 respectively, and therefore no significant difference is detected based on the alpha value of 0.05.

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 7.27 sightings and 26.00 dolphins per 100 km of survey effort respectively, while the encounter rates of sightings (STG) and dolphins (ANI) in NEL were 0.59 sightings and 0.59 dolphins per 100 km of survey effort respectively.

Group Size

3.5.22    Group size of Chinese White Dolphins ranged from 1-20 individuals per group in North Lantau region during March to May 2013.  The average dolphin group sizes from these three months were compared with the one deduced from the baseline period in September to November 2011, as shown in Table 3.6.

Table 3.6         Comparison of Average Dolphin Group Sizes between Reporting Period (March 2013 to May 2013) and Baseline Monitoring Period (Sep– Nov 2011)

 

Average Dolphin Group Size

Reporting Period

Baseline Monitoring Period

Overall

3.26 ± 3.89 (n = 39)

3.72 ± 3.13 (n = 66)

Northeast Lantau

1.00 ± 0.00 (n = 2)

3.18 ± 2.16 (n = 17)

Northwest Lantau

3.38 ± 3.96 (n = 37)

3.92 ± 3.40 (n = 49)

 

3.5.23    The average dolphin group sizes in the entire North Lantau region during March to May 2013 was slightly lower than the ones recorded in the 3-month baseline period (Table 3.6).  Notably, the two sightings made in NEL during the present monitoring period were comprised of two lone dolphins, hence the average dolphin group size was much lower than the baseline period.  On the other hand, the average dolphin group size in NWL during the present monitoring period was slightly lower than the baseline period (Table 3.6).

3.5.24    Distribution of dolphins with larger group sizes during March – May 2013 is shown in Figure 2 of Appendix J. There were much fewer large dolphin groups recorded (four groups with more than 10 animals and one group with more than 5 animals) during the present monitoring period when compared with the baseline period (two groups with more than 10 animals and 16 groups with more than 5 animals). These five large dolphin groups were scattered within and around the Sha Chau and Lung Kwu Chau Marine Park (Figure 2 of Appendix J).

Habitat Use

3.5.25    From March-May 2013, the most heavily utilized habitats by Chinese White Dolphins mainly concentrated along the Urmston Road section between Lung Kwu Chau and Black Point as well as around Sha Chau (Figures 3a and 3b of Appendix J). Only two grids in NEL recorded the presence of dolphins in very low density based on two sightings of two lone dolphins.  None of the grid around HKLR03 or HKBCF work site recorded the presence of dolphins.     

3.5.26    It should be noted that the amount of survey effort collected in each grid during the three-month period was still 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 will be presented when more survey effort for each grid will be collected throughout the impact phase monitoring programme.

3.5.27    When compared with the habitat use patterns during the baseline period, the usage of NEL was significantly less as well as overall number of grids with presence of dolphins were much fewer during the present impact monitoring period (Figure 4 of Appendix J). Moreover, dolphins were generally absent from the habitat around the Brothers and near Shum Shui Kok in NEL that was identified during the baseline period.  From the same comparison between the two quarterly periods, it appears that dolphins have been less found in the construction sites of HKLR03 in the present monitoring period (Figure 4 of Appendix J) and it should be noted that the construction site of HKLR03 situates in waters which has rarely been used by dolphins in the past. Hence there is no evidence showing that the sources of impact were directly related to the construction works of HKLR03 that may have affected the dolphin usage in the NEL region. 

Mother-calf Pairs

3.5.28    During the three-month study period, a total of six unspotted juveniles (UJ) were sighted in NEL and NWL survey areas, while no unspotted calves (UC) were sighted.  These young calves comprised 4.7% of all animals sighted, which was lower than the percentage recorded during the baseline monitoring period (6.8%).

3.5.29    These young calves mainly occurred within and around the Sha Chau and Lung Kwu Chau Marine Park (Figure 5 of Appendix J).  Notably, no young calves were found in the vicinity of HZMB-related construction sites.

Activities and Associations with Fishing Boats

3.5.30    A total of four dolphin sightings were associated with feeding and socializing activities during the three-month study period, comprising of 7.7% and 2.6% of the total number of dolphin sightings.  Both percentages were lower than the percentages recorded during the baseline period (feeding activity: 11.6%; socializing activity: 5.4%).  Only one group of dolphins was engaged in traveling activity.

3.5.31    Distribution of dolphins engaged in different activities during the three-month study period is shown in (Figure 6 of Appendix J).  Most of the feeding and socializing activities occurred within and around the Sha Chau and Lung Kwu Chau Marine Park.  Moreover, one group of ten dolphins was engaged in traveling activity to the west of Sha Chau close to the Hong Kong-Guangdong border. All these activities were far away from the HZMB-related construction works.

3.5.32    During the three-month period, only one dolphin group were found to be associated with an operating purse-seiner, comprising of 2.6% of all dolphin groups, which was much lower than the percentage recorded in baseline period (5.4%).  The low percentage of fishing boat association was likely related to the recent trawl ban being implemented in 2013 in Hong Kong waters.

Photo-identification and Individual Range Use

3.5.33    From March to May 2013, over 2,000 digital photographs of Chinese White Dolphins were taken during the impact phase monitoring surveys for the for the photo-identification work.

3.5.34    In total, 34 individuals sighted 58 times altogether were identified (see summary table in Annex III and photographs of identified individuals in Annex IV of Appendix J).  Only one of these 58 re-sightings were made in NEL, which involved the individual NL18 that was also the most frequently sighted individuals in NEL during previous months of HKLR03 monitoring works.  On the contrary, a number of year-round residents that occurred in NEL regularly before (e.g. EL01, NL123, NL285, NL179) have disappeared from this survey area during the present monitoring period.

3.5.35    Most identified individuals were sighted only once or twice during the three-month period, with the exception of two individuals being sighted thrice (NL93, NL244) and three individuals being sighted four times (NL104, NL202 and NL286).

3.5.36    Five well-recognized females, including NL33, NL46, NL93, NL104 and NL202, were accompanied with their calves during their re-sightings.  These mother-calf pairs were frequently seen throughout the HKLR03 impact phase monitoring period.

3.5.37    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. 

3.5.38    Only one individual (NL18) was sighted in the NEL survey area while other individuals were mostly found in the NWL survey area during this quarterly period.  In contrast to the extensive movements between NEL and NWL survey areas in previous two impact monitoring periods and the baseline period, most identified individuals have avoided NEL during March-May 2013, even though they were frequently sighted there before and their core areas were centered around the Brothers Islands (i.e. NL24, NL33, NL261) (Annex V of Appendix J). 

3.5.39    Moreover, a number of year-round residents that used to utilize the Brothers Islands as their core areas have not been seen there during the past two quarters.  This apparent shift in range use of many individual dolphins should be continuously monitored in the upcoming quarterly periods to determine whether this is related to the disturbance associated with the HZMB-related construction activities.

3.5.40    It should be noted that a number of individuals that focused their activities in West Lantau waters in the past were also sighted in NWL (e.g. WL44, WL46, WL50, WL98) (Annex V of Appendix J).  The movement of these individuals between North and West Lantau waters should be continuously monitored to determine whether their range use will be affected by the HKLR09 construction works.

Action Level / Limit Level Exceedance

3.5.41    There was one Action Level exceedance of dolphin monitoring for the quarterly monitoring data (March – May 2013). The possible reasons for Action Level non-compliance could be due to the seasonal fluctuation of dolphin occurrence in spring months in the Northeast Lantau region.  According to AFCD long-term monitoring data, dolphins were infrequently sighted in NEL during spring months as compared to the other three seasons (Hung 2011, 2012), and the current AL non-compliance also occurred in NEL during spring months. There is no evidence showing the current AL non-compliance directly related to the construction works of HKLR03.  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 – Sham Shui Kok Anchorage (near Brothers Island) as far as practicable. 

3.5.42    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).  For the comparison between the baseline period and the present quarter (third quarter of the impact phase), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.0858 and 0.0931 respectively.  If the alpha value is set at 0.1 (due to the small sample size with lower statistical power in the analysis), significant difference was detected between the baseline and present quarters. For the comparison between the baseline period and the cumulative quarters in impact phase (i.e. first three quarters of the impact phase), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.1336 and 0.0507 respectively.  If the alpha value is set at 0.1, significant difference is detected in the average dolphin encounter rate of ANI (i.e. between the two periods and the locations), but not in the average dolphin encounter rate of STG.  The AFCD monitoring data during March-May 2013 has been reviewed by the dolphin specialist, and no dolphin sighting was made with 66.04 km of survey effort on primary lines in NEL during the same quarter.  This review has confirmed that the very low occurrence of dolphins reported by the HKLR03 monitoring survey in spring 2013 in NEL is accurate.

3.5.43    All dolphin protective measures are fully and properly implemented in accordance with the EM&A Manual.  In order to minimise disturbance to the Brother’s Island, the Contractor provide training to 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 possible. 

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 23 March 2013.  The mudflat surface levels at the four established monitoring stations and the corresponding XYZ HK1980 GRID coordinates are presented in Table 3.6 and Table 3.7.

Table 3.6          Measured Mudflat Surface Level Results

Baseline Monitoring
(September 2012)

Impact Monitoring
(March 2013)

Monitoring Station

Easting (m)

Northing (m)

Surface Level

Easting (m)

Northing (m)

Surface Level

(mPD)

(mPD)

S1

810291.160

816678.727

0.950

810291.111

816678.640

0.995

S2

810958.272

815831.531

0.864

810958.296

815831.551

0.953

S3

810716.585

815953.308

1.341

810716.583

815953.344

1.422

S4

811221.433

816151.381

0.931

811221.485

816151.324

1.068


 

Table 3.7          Comparison of measurement  

Comparison of measurement

Remarks and Recommendation

Monitoring Station

Easting (m)

Northing (m)

Surface Level
(mPD)

S1

-0.049

-0.087

0.045

Within tolerance, no significant change

S2

0.024

0.019

0.091

Level continuously increased

S3

-0.003

0.036

0.081

Level continuously increased

S4

0.052

-0.057

0.137

Level continuously increased

 

3.6.2       This measurement was generally and relatively higher than the baseline measurement at S3, S2 and S4. The mudflat level is continuously increased.  For S1, the level has increased within tolerance and their sea bed depth would not be considered as significant change.

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 March 2013.  The monitoring parameters included dissolved oxygen (DO), turbidity and suspended solids (SS).

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

Table 3.8          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)

01-Mar-13

8.0

3.35

5.7

7.4

4.5

8.6

04-Mar-13

7.8

3.1

5.95

7.4

4.5

8.6

06-Mar-13

8.2

2.5

3.35

7.8

2.4

3.9

08-Mar-13

8.9

2.25

3.5

8.9

2.4

3.6

11-Mar-13

8.5

4.4

4.25

8.3

6.7

7.1

13-Mar-13

7.7

2.85

3.85

7.6

3.4

5.5

15-Mar-13

7.2

3.15

3.85

7.2

4.1

4.6

18-Mar-13

7.5

4.35

4.7

7.1

4.9

4.3

20-Mar-13

7.7

2.65

2.55

6.8

3.7

3.8

22-Mar-13

7.1

3.5

3.3

7.4

6.5

8.3

25-Mar-13

7.1

10.65

8.85

7.0

7.7

11.4

27-Mar-13

7.1

7.9

14.5

6.9

13.3

17.6

29-Mar-13

6.8

8.15

5.8

6.7

13.5

14.6

Average

7.7

4.5

5.4

7.4

6.0

7.8


 

Mudflat Ecology Monitoring

Sampling Zone

3.6.6       There are two survey areas specified under the updated EM&A Manual for the Contract, namely Tung Chung Bay and San Tau.  Tung Chung Bay survey area is divided into three sampling zones (TC1, TC2 and TC3) and there is one sampling zone at San Tau (ST).  Survey of horseshoe crabs, seagrass beds and intertidal communities were conducted in each sampling zone.  The locations of sampling zones are shown in Figure 2.1. 

Horseshoe Crabs

3.6.7       An active search method was adopted for horseshoe crab survey at each sampling zone. The survey was undertaken by 2 specialists at each 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 was found, the species, size and inhabiting substrate, photographic record and respective GPS coordinate were recorded with reference to Li (2008). The horseshoe crab surveys were conducted on 11th (for zones TC1 and TC2) and 12th (for zones TC3 and ST) March 2013 with windy and cloudy weather.

Seagrass Beds

3.6.8       An active search method was adopted for seagrass bed survey at each sampling zone.  The survey was undertaken by 2 specialists each spending within 2-3 hours in low tide period.  Once seagrass bed was observed, the species, the estimated area (m2), photographic record and respective GPS coordinate were recorded.  The seagrass bed surveys were conducted on 11th (for zones TC1 and TC2) and 12th (for zones TC3 and ST) March 2013 with windy and cloudy weather.

Intertidal Soft Shore Communities

3.6.9       The sandy shore of San Tau and Tung Chung Bay from the uppermost part of the shore and to the water edge was divided into three tidal zones – upper, middle and lower zones, at each sampling zone, TC1, TC2, TC3 and ST.  A 100m transect was laid in each of the three tidal zones for fauna sampling.

3.6.10    At each sampling zone, three 100m horizontal transects were laid at 2.0m, 1.5m and 1.0m above C.D.  Along each transect, ten random quadrats (0.5 m x 0.5m) were placed.  In each quadrat, the epifauna and infauna (within the top 5cm sediment) in each quadrat were identified and their numbers/coverage percentages were recorded.  One core of 10cm diameter x 20cm depth was also collected within each quadrat.  The sediments of the cores were sieved with 2mm mesh-size sieve and the biota inside was identified and counted.  All collected fauna were released after recording except some tiny individuals that in-situ identification was not feasible. These tiny individuals were collected and were identified in the laboratory.  Species and abundance of biota in both cores and quadrats were reported.  The intertidal soft shore community surveys were conducted in low tide period on 2nd (for TC2), 3rd (for TC1), 10th (for ST) and 16th March 2013 (for TC3).

Data Analysis

3.6.11    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’= -Σ ( 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

3.6.12    Table 3.1 and Figure 3.1 of Appendix O show the records of horseshoe crab survey at every sampling zone. In general, horseshoe crab Tachypleus tridentatus was found at TC1 (5 individuals), TC3 (2 individuals) and ST (15 individuals).  All individuals were found on either soft mud or sandy substratum. Grouping was observed while each group consisted of 2 individuals only. One individual was just completed moulting at TC3. Another individual was found with broken prosoma at ST that might be caused by birds’ pecking.  Another horseshoe crab species Carcinoscorpius rotundicauda, reported at ST in previous survey (December 2012) was not encountered in the present survey.

3.6.13    According to Table 3.2 of Appendix I, the search records of Tachypleus tridentatus were
1.25 individuals hr-1 person-1 (mean prosomal widths: 40.68 mm) and 0.50 individuals hr-1 person-1 (34.71 mm) at TC1 and TC3, respectively. Similar to previous surveys, the highest search record of 3.00 individuals hr-1 person-1 (32.46 mm) was reported at ST.  According to Li (2008), the prosomal width of Tachypleus tridentatus recorded ranged 15.0247.98 mm that corresponded to an estimated age of 2.15.8 years old. Summary of prosomal width of horseshoe crab is shown in Table 3.9.

Table 3.9          Summary of Prosomal Width of Horseshoe Crab Survey

Sampling Zone

TC1

TC2

TC3

ST

Search duration (hr)

2

2

2

2.5

Tachypleus tridentatus

No. of individuals

5

N.A.

2

15

Mean prosomal width (mm)

40.68

N.A.

34.71

32.46

Range of prosomal width (mm)

34.31-47.98

N.A.

28.29-41.12

15.02-42.73

Search record
(individual hr-1 person-1)

1.25

N.A.

0.50

3.00

 

3.6.14    Figure 3.2 of Appendix O shows the changes of number of individuals, mean prosomal width and search record of horseshoe crab Tachypleus tridentatus at the four sampling zones along the sampling months. From September to December 2012, the search records declined generally at all sampling zones during dry season. The horseshoe crabs were inactive and burrowed in the sediments during cold weather (<15 ºC).  Similar results of low search record in dry seasons were reported in a previous territory-wide survey of horseshoe crab. For example, the search records at Tung Chung Wan were 0.17 individuals hr-1 person-1 and
0
individual hr-1 person-1
in wet season and dry season respectively (details see Li, 2008). From December 2012 to March 2013 (present survey), the search records increased at the three sampling zones with the increased ambient temperature. Therefore, significant changes of population structure or cohort pattern were not determined.

3.6.15    By comparing the search record and mean prosomal width of Tachypleus tridentatus among the sampling zones, ST was usually inhabited by more individuals of smaller size. Larger individuals were usually found at TC1 and TC3 at lower abundance. ST was believed a more important nursery ground for horseshoe crab especially newly hatched individuals. When reaching larger size of higher mobility, few individuals might migrate to nearby sampling zones TC1 and TC3 for foraging.

3.6.16    The present survey was the second time of sampling of the EM&A programme during the construction period. Based on the results, impacts of the HKLR project could not be detected on horseshoe crabs considering the factor of natural, seasonal variation, In case, abnormal phenomenon (e.g. very few numbers of horseshoe individuals in warm weather) is observed, it would be reported as soon as possible.

Seagrass Beds

3.6.17    Table 3.3 and Figure 3.3 of Appendix O show the records of seagrass beds survey at every sampling zone. Three patches of Halophila ovalis were recorded nearby the mangrove vegetation at tidal level 2 m above C.D. at ST. The estimated total area and mean area were 528.8 m2 and 176.3 m2 respectively while the estimated coverage ranged 70-100%. One of the patches was a long seagrass strand with estimated total area 442.2 m2.

3.6.18    Three small patches of Zostera japonica were found within the long strand of Halophila ovalis. The estimated total area and mean area were 10.4 m2 and 3.5 m2 respectively while the estimated coverage ranged 15-50% only. Since Zostera japonica was not reported in the previous surveys, it indicated the seasonal recruitment of this seagrass species between December and March.

3.6.19    Figure 3.4 of Appendix O shows the changes of estimated total area of seagrass beds Halophila ovalis at ST along the sampling months. Relative to previous surveys, the total area and estimated coverage increased gradually. Since the location of seagrass was the same, it was believed that scattered patches of seagrass grew and merged into single, large patch.

Intertidal Soft Shore Communities

3.6.20    Table 3.4 and Figure 3.5 of Appendix O show the types of substratum along the horizontal transect at every tidal level of every sampling zone. The relative distribution of different substrata was estimated by investigating the substratum types (Gravels & Boulders / Sands / Soft mud) of the ten random quadrats along every horizontal transect.

3.6.21    The distribution of substratum types varied strongly among tidal levels and sampling zones.  At TC1, even distribution of ‘Gravels and Boulders’ (50%) and ‘Sands(40%) were recorded at high tidal level. Higher percentage of ‘Gravels and Boulders’ (80-90%) was recorded at mid and low tidal levels. At TC2, high percentage of ‘Sands(70-90%) was recorded at high and mid tidal levels while ‘Soft mud’ was recorded only (100%) at low tidal level. At TC3, high percentage of ‘Sands’ (70-90%) was recorded at high and mid tidal levels followed by ‘Soft mud’ (10-30%). ‘Gravels and Boulders’ was recorded only (100%) at low tidal level. At ST, ‘Gravels and Boulders’ (100%) and ‘Soft mud’ (100%) were recorded only at high and low tidal levels respectively. Even distribution of ‘Sands’ (60%) and ‘Gravels and Boulders’ (40%) was recorded at mid tidal level.

3.6.22    There was neither consistent vertical nor horizontal zonation pattern of substratum type in the study site. Such heterogeneous variation should be caused by different hydrology (e.g. wave in different direction and intensity) received by the four sampling zones

3.6.23    Table 3.5 of Appendix O lists the total abundance, density and number of taxon of every phylum in the present survey. A total of 20159 individuals were recorded. Mollusks were significantly the most abundant phylum (total individuals 19714, density 657 individuals m-2, relative abundance 97.8%). The second abundant group was arthropod (total individuals: 339, density 11 individuals m-2, 1.7%) respectively. Relatively other phyla were very low in abundance (£0.4%). Similarly, the most diverse phylum were mollusks (38 taxa) followed by annelids (14 taxa) and arthropods (12 taxa). The number of taxon of other phyla was relatively small (£ 2 taxa). The complete list of collected specimens is provided in Annex III of Appendix O.

3.6.24    Table 3.6 of Appendix O shows the number of individual, relative abundance and density of each phylum at every sampling zone. The results were similar among the four sampling zones. In general, mollusks were the most dominant phylum (no. of individuals: 2708-6491 individuals, relative abundance 92.5-99.3%). Arthropods were the second abundant phylum (no. of individuals: 30-201 individuals, 0.5-6.9%) although the number of individuals was significantly lower than that of mollusks. Relatively, other phyla were very low in abundance across the four sampling zones (< 1%).

3.6.25    Table 3.7 of Appendix O lists the abundant species (relative abundance >10%) at every sampling zone. At TC1, gastropod Batillaria multiformis was a clearly dominant species (203-693 individuals m-2, relative abundance 31-89%) regardless of tidal levels. Rock oyster Saccostrea cucullata was the second abundant species (164-170 individuals m-2, 16-26%) at mid and low tidal levels. Gastropod Monodonta labio was the third abundant species (151 individuals m-2, 23%) at low tidal level.

3.6.26    At TC2, gastropod Batillaria multiformis was highly abundant (308 individuals m-2, relative abundance 62%) at high tidal level followed by gastropod Cerithidea djadjariensis (86 individuals m-2, 17%). At mid tidal level, gastropod Cerithidea djadjariensis was the most abundant (128 individuals m-2, 34%) while rock oyster Saccostrea cucullata (72 individuals m-2, 19%), gastropod Batillaria zonalis (50 individuals m-2, 13%) and Cerithidea cingulata (43 individuals m-2, 11%) were other abundant species at lower density. At low tidal level, the abundant species were gastropod Batillaria zonalis (76 individuals m-2, 26%), Cerithidea djadjariensis (70 individuals m-2, 24%), rock oyster Saccostrea cucullata (64 individuals m-2, 22%) and barnacle Balanus amphitrite (50 individuals m-2, 17%) at similar density. 

3.6.27    At TC3, the high and mid tidal levels were mainly dominated by gastropods Batillaria multiformis (532-652 individuals m-2, relative abundance 65-67%) and Cerithidea djadjariensis (166-214 individuals m-2, 20-22%). At low tidal level, the abundant species were rock oyster Saccostrea cucullata (282 individuals m-2, 34%), gastropods Batillaria multiformis (280 individuals m-2, 34%) and Monodonta labio (154 individuals m-2, 19%) at similar density.

3.6.28    At ST, gastropod Batillaria multiformis was highly abundant (845 individuals m-2, relative abundance 75%) at high tidal level followed by gastropod Monodonta labio (114 individuals m-2, 10%). At mid tidal level, rocky oyster Saccostrea cucullata (136 individuals m-2, 25%) and gastropod Cerithidea djadjariensis (120 individuals m-2, 22%) were abundant species at mid tidal level followed by gastropod Batillaria multiformis (62 individuals m-2, 11%) at lower density. Relatively, the abundant species rocky oyster Saccostrea cucullata (39 individuals m-2, 26%), gastropod Batillaria zonalis (32 individuals m-2, 21%) and Cerithidea djadjariensis (31 individuals m-2, 20%) were lower in density at low tidal level.

3.6.29    There was no consistent zonation pattern of species distribution observed across sampling zones and tidal levels in Tung Chung Wan and San Tau. The species distribution should be determined by the type of substratum primarily. In general, gastropod Batillaria multiformis (in present survey = 10710 individuals), Cerithidea djadjariensis (2367 individuals), Monodonta labio (1443 individuals) and rocky oyster Saccostrea cucullata (2653 individuals) were the most common occurring species among the four sampling zones.

3.6.30    Table 3.8 shows the mean values of number of species, density, H’ and J of soft shore communities at every tidal level and sampling zone. Among the sampling zones, the mean number of species was similar and ranged 6-13 spp. 0.25 m-2. The mean densities of TC1 (647-1020 individuals m-2), TC3 (819-970 individuals m-2) and ST (151-1126 individuals m-2) were generally higher than that of TC2 (296-498 individuals m-2). For ST, the mean density was obviously higher at high tidal level. The mean biodiversity index and species evenness were similar that ranged 1.12-1.40 and 0.50-0.65 respectively.

3.6.31    Across the tidal levels, there was no consistent pattern of the mean number of species and mean density. In general higher biodiversity index and species evenness were observed at lower tidal levels (1.0-1.5 m above C.D.).

3.6.32    Figure 3.6 of Appendix O shows the temporal changes of number of species, density, H’ and J at every tidal level and sampling zone since the baseline monitoring survey (Sep 2012). No significant temporal change was observed at all sampling zones. Although declined densities were reported at sampling zones TC2 (mid and low tidal levels) and TC3 (high and mid tidal levels) in dry season (Dec 2012), it was believed a natural, seasonal variation due to higher mortality and lower activity rate of intertidal fauna during cold, dry season. The densities of both sampling zones had increased in the present survey with the warm weather.

3.6.33    The present survey was the second time of sampling of the EM&A programme during the construction period. Based on the results, impacts of the HKLR project could not be detected on intertidal soft shore community.

3.7                Solid and Liquid Waste Management Status

3.7.1       The Contractor registered with EPD as a Chemical Waste Producer on 12 July 2012 for the Contract.  Sufficient numbers of receptacles were available for general refuse collection and sorting.

3.7.2       The summary of waste flow table is detailed in Appendix K.

3.7.3       The Contractor was reminded that chemical waste containers should be properly treated and stored temporarily in designated chemical waste storage area on site in accordance with the Code of Practise on the Packaging, Labelling and Storage of Chemical Wastes.

3.8                Environmental Licenses and Permits

3.8.1       The valid environmental licenses and permits during the reporting period are summarized in Appendix L.

 

 


4        Environmental Complaint and Non-compliance

4.1.1       The detailed air quality, noise, water quality and dolphin exceedances are provided in Appendix M. Also, the summaries of the environmental exceedances are presented as followed:

Air Quality

4.1.2       There were no Action and Limit Level exceedance for 1-hr TSP or 24-hr TSP recorded air quality were recorded during the reporting period.

Noise

4.1.3       There were 4 Action Level exceedances of noise were recorded during the reporting period. All noise exceedances were considered not related to project. No Limit Level exceedances for noise were recorded at the monitoring station during the reporting period.  

Water Quality

4.1.4     During the reporting period, there are 16 Action Level exceedances and 87 Limit Level exceedances of suspended solids level.  8 Action Level exceedances and 78 Limit Level exceedances of turbidity level were recorded.  No major marine works were undertaken near the monitoring stations. Geotextile installation, rock filling, silt curtain maintenance work and vessel maintenance work were being carried out within silt curtains near the restricted area during the sampling period. These activities were unlikely to cause adverse water quality impact.  Therefore, all exceedances were considered not project related.  The detailed numbers of exceedances recorded during the reporting period at each impact station are summarised in Table 4.1.

Dolphin

4.1.5     There was one Action Level exceedance of dolphin monitoring for the quarterly monitoring data (March – May 2013). The possible reasons for Action Level non-compliance could be due to the seasonal fluctuation of dolphin occurrence in spring months in the Northeast Lantau region.  According to AFCD long-term monitoring data, dolphins were infrequently sighted in NEL during spring months as compared to the other three seasons (Hung 2011, 2012), and the current AL non-compliance also occurred in NEL during spring months. There is no evidence showing the current AL non-compliance directly related to the construction works of HKLR03.  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 – Sham Shui Kok Anchorage (near Brothers Island) as far as practicable.  All dolphin protective measures are fully and properly implemented in accordance with the EM&A Manual.