
Contract
No. HY/2011/03
Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road
Section between Scenic Hill and Hong Kong Boundary Crossing Facilities
Quarterly EM&A Report No.
13 (Sep 2015 to Nov 2015)
18
April 2016
Revision 1
Main Contractor Designer
Executive Summary
The Hong Kong-Zhuhai-Macao Bridge (HZMB) Hong
Kong Link Road (HKLR) serves to connect the HZMB Main Bridge at the Hong Kong
Special Administrative Region (HKSAR) Boundary and the HZMB Hong Kong Boundary
Crossing Facilities (HKBCF) located at the north eastern waters of the Hong
Kong International Airport (HKIA).
The HKLR project has been separated into two
contracts. They are Contract No.
HY/2011/03 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between
Scenic Hill and Hong Kong Boundary Crossing Facilities (hereafter referred to
as the Contract) and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong
Kong Link Road-Section between HKSAR Boundary and Scenic Hill.
China State Construction Engineering (Hong Kong)
Ltd. was awarded by Highways Department as the Contractor to undertake the
construction works of Contract No. HY/2011/03. The main works of the Contract include
land tunnel at Scenic Hill, tunnel underneath Airport Road and Airport Express
Line, reclamation and tunnel to the east coast of the Airport Island, at-grade
road connecting to the HKBCF and highway works of the HKBCF within the Airport
Island and in the vicinity of the HKLR reclamation. The Contract is part of the HKLR Project
and HKBCF Project, these projects are considered to be ¡§Designated Projects¡¨,
under Schedule 2 of the Environmental Impact Assessment (EIA) Ordinance (Cap
499) and EIA Reports (Register No. AEIAR-144/2009 and AEIAR-145/2009) were
prepared for the Project. The
current Environmental Permit (EP) EP-352/2009/D for HKLR and EP-353/2009/K for
HKBCF were issued on 22 December 2014 and 11 April 2016, respectively. These
documents are available through the EIA Ordinance Register. The construction
phase of Contract was commenced on 17 October 2012.
BMT Asia Pacific Limited has been appointed by
the Contractor to implement the Environmental Monitoring & Audit (EM&A)
programme for the Contract in accordance with the Updated EM&A Manual for
HKLR (Version 1.0) and will be providing environmental team services to the
Contract.
This is the thirteenth Quarterly EM&A report
for the Contract which summarizes the monitoring results and audit findings of
the EM&A programme during the reporting period from 1 September 2015 to 30 November 2015.
Environmental
Monitoring and Audit Progress
The EM&A programme
were undertaken in accordance with the Updated EM&A Manual for HKLR
(Version 1.0). A summary of the
monitoring activities during this reporting period is presented as below:
Monitoring Activity
|
Monitoring Date
|
September 2015
|
October
2015
|
November
2015
|
Air
Quality
|
1-hr TSP
|
2, 8, 14, 18, 24 and 30
|
6, 12, 16, 22 and 27
|
2, 6, 12, 18, 24 and 30
|
24-hr TSP
|
1, 7, 11, 17, 23 and 29
|
AMS5: 5, 9, 15, 20, 26 and 30
AMS6: 5, 9, 15, 20 and 26
|
AMS5: 5, 11, 17, 23 and 27
AMS6: 5, 11, 17 and 27
|
Noise
|
4, 8, 14, 24 and 30
|
6, 12, 22 and 27
|
2, 12, 18, 24 and 30
|
Water
Quality
|
2, 4, 7, 9, 11, 14, 16, 18, 21, 23, 25, 28
and 30
|
2, 5, 7, 9, 12, 14, 16, 19, 21, 23, 26, 28
and 30
|
2, 4, 6, 9, 11, 13, 16, 18, 20, 23, 25, 27
and 30
|
Chinese
White Dolphin
|
2, 11, 17 and 29
|
6, 13, 19 and 26
|
2, 6, 10 and 16
|
Mudflat
Monitoring (Ecology)
|
5, 6, 10, 12 and
13
|
-
|
-
|
Mudflat
Monitoring (Sedimentation rate)
|
10
|
-
|
-
|
Site Inspection
|
2, 9, 16, 25 and 30
|
7, 14, 22 and 30
|
4, 11, 18 and 27
|
Due to bad weather
condition on 2 Sep 2015, noise monitoring at NMS5 was rescheduled from 2 Sep
2015 to 4 Sep 2015.
Due to boat
availability issue, the dolphin monitoring schedule was rescheduled from 15 Sep
2015 to 17 Sep 2015, from 21 Sep 2015 to 29 Sep 2015 and from 9 October 2015 to
13 October 2015.
Due to weather
condition, the dolphin monitoring schedule was rescheduled from 5 October 2015
to 6 October 2015, from 23 October 2015 to 26 October 2015, from 5 November
2015 to 6 November 2015 and from 13 November 2015 to 16 November 2015.
Due to malfunctioning of HVS at station AMS6,
the 24-hr TSP monitoring at station AMS6 on 30 October 2015 was cancelled.
Due to power interruption at station
AMS6 on 23 November 2015, the 24-hr TSP monitoring result obtained at AMS6 on
23 November 2015 was not completed and considered invalid.
Breaches
of Action and Limit Levels
A summary of environmental exceedances for this
reporting period is as follows:
Environmental Monitoring
|
Parameters
|
Action Level (AL)
|
Limit Level (LL)
|
Air
Quality
|
1-hr TSP
|
0
|
0
|
24-hr TSP
|
0
|
0
|
Noise
|
Leq
(30 min)
|
0
|
0
|
Water
Quality
|
Suspended
solids level (SS)
|
10
|
0
|
Turbidity
level
|
0
|
0
|
Dissolved
oxygen level (DO)
|
0
|
0
|
Dolphin
Monitoring
|
Quarterly
Analysis (Sep to Nov 2015)
|
2
|
0
|
The Environmental Team investigated all
exceedances and found that they were not project related.
All investigation reports for exceedances of the
Contract have been submitted to ENPO/IEC for comments and/or follow up to
identify whether the exceedances occurred related to other HZMB contracts.
Implementation of Mitigation Measures
Site inspections were carried out on a weekly
basis to monitor the implementation of proper environmental pollution control
and mitigation measures for the Project.
Potential environmental impacts due to the construction activities were
monitored and reviewed.
Complaint Log
There
was one complaint received in relation to the environmental impact during the
reporting period.
A summary of environmental complaints for this
reporting period is as follows:
Environmental Complaint No.
|
Date of Complaint Received
|
Description of Environmental
Complaints
|
COM-2015-079
|
7 December 2015
|
Water Quality
|
Notifications of Summons and Prosecutions
There were no notifications of summons or
prosecutions received during this reporting period.
Reporting Changes
This report has been developed in compliance
with the reporting requirements for the quarterly summary EM&A reports as
required by the Updated EM&A Manual for HKLR (Version 1.0).
The proposal for the change of Action Level and
Limit Level for suspended solid and turbidity was approved by EPD on 25 March
2013.
The revised Event and Action Plan for dolphin monitoring was approved by EPD on 6 May 2013.
The original monitoring station at IS(Mf)9
(Coordinate- East:813273, North 818850) was observed inside the perimeter silt
curtain of Contract HY/2010/02 on 1 July 2013, as such the original impact
water quality monitoring location at IS(Mf)9 was temporarily shifted outside
the silt curtain. As advised by the
Contractor of HY/2010/02 in August 2013, the perimeter silt curtain was shifted
to facilitate safe anchorage zone of construction barges/vessels until end of
2013 subject to construction progress.
Therefore, water quality monitoring station IS(Mf)9 was shifted to
813226E and 818708N since 1 July 2013.
According to the water quality monitoring team¡¦s observation on 24 March
2014, the original monitoring location of IS(Mf)9 was no longer enclosed by the
perimeter silt curtain of Contract HY/2010/02. Thus, the impact water quality
monitoring works at the original monitoring location of IS(Mf)9 has been
resumed since 24 March 2014.
Transect lines 1, 2, 7, 8, 9 and 11 for dolphin
monitoring have been revised due to the obstruction of the permanent structures
associated with the construction works of HKLR and the southern viaduct of
TM-CLKL, as well as provision of adequate buffer distance from the Airport
Restricted Areas. The EPD issued a
memo and confirmed that they had no objection on the revised transect lines on
19 August 2015.
1.1.2 The HKLR project has been separated into two contracts. They are Contract
No. HY/2011/03 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section
between Scenic Hill and Hong Kong Boundary Crossing Facilities (hereafter
referred to as the Contract) and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao
Bridge Hong Kong Link Road-Section between HKSAR Boundary and Scenic Hill.
1.1.3
China State Construction
Engineering (Hong Kong) Ltd. was awarded by Highways Department (HyD) as the
Contractor to undertake the construction works of Contract No. HY/2011/03. The Contract is part of the HKLR
Project and HKBCF Project, these projects are considered to be ¡§Designated
Projects¡¨, under Schedule 2 of the Environmental Impact Assessment (EIA)
Ordinance (Cap 499) and EIA Reports (Register No. AEIAR-144/2009 and
AEIAR-145/2009) were prepared for the Project. The current Environmental Permit (EP)
EP-352/2009/D for HKLR and EP-353/2009/K for HKBCF were issued on 22 December
2014 and 11 April 2016, respectively. These documents are available through the
EIA Ordinance Register. The construction
phase of Contract was commenced on 17 October
2012. Figure 1.1 shows the project site boundary.
1.1.5
This is the thirteenth Quarterly Environmental Monitoring and Audit
(EM&A) report for the Contract which summarizes the monitoring results and
audit findings of the EM&A programme during the reporting period from 1
September 2015 to 30 November 2015.
1.2.1 The project organization structure and lines of
communication with respect to the on-site environmental management structure
with the key personnel contact names and numbers are shown in Appendix A.
1.3
Construction
Programme
1.3.1
A copy of the Contractor¡¦s construction programme
is provided in Appendix B.
1.4
Construction Works Undertaken During
the Reporting Period
1.4.1
A summary of the construction activities
undertaken during this reporting period is shown in Table
1.1. The Works areas of the Contract are
showed in Appendix
C.
Table 1.1 Construction
Activities during Reporting Period
Description of Activities
|
Site Area
|
Dismantling/trimming of temporary 40mm stone platform for construction
of seawall
|
Portion X
|
Filling works behind stone platform
|
Portion X
|
Construction of seawall
|
Portion X
|
Loading and unloading of filling materials
|
Portion X
|
Band drains installation
|
Portion X
|
Excavation and lateral support works for Scenic Hill Tunnel (Cut &
Cover Tunnel)
|
Portion X
|
Socket H-Piling work for Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Laying blinding layer for tunnel box structure at Scenic Hill Tunnel
(Cut & Cover Tunnel)
|
Portion X
|
Construction of
Sheet Pile
at Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Construction of tunnel box structure at Scenic Hill Tunnel (Cut &
Cover Tunnel)
|
Portion X
|
Pipe piling works for HKBCF to Airport Tunnel East (Cut & Cover
Tunnel)
|
Portion X
|
Excavation for HKBCF to Airport Tunnel
|
Portion X
|
Sheet Piling Works for
HKBCF to Airport Tunnel East (Cut & Cover Tunnel)
|
Portion X
|
Socket H-Piling Works for
HKBCF to Airport Tunnel East (Cut &Cover Tunnel)
|
Portion X
|
Excavation for Scenic Hill Tunnel
|
West
Portal
|
Ventilation building foundation and superstructure works
|
West
Portal
|
Superstructure works for
Scenic Hill Tunnel West Portal Ventilation building
|
West
Portal
|
Pipe piling works for
HKBCF to Airport Tunnel West (Cut & Cover Tunnel)
|
Airport
Road
|
Works for diversion of Airport Road
|
Airport
Road
|
Utilities detection
|
Airport
Road/ Airport Express Line/ East Coast Road
|
Establishment of Site Access
|
Airport
Road/ Airport Express Line/ East Coast Road
|
Canopy pipe drilling underneath Airport Express Line
|
Airport
Express Line
|
Excavation and lateral support works at shaft 3 extension north shaft
& south shaft
|
Kwo Lo Wan
Road
|
Excavation and Lateral Support Works for HKBCF to Airport Tunnel West
(Cut & Cover Tunnel)
|
Airport Road
|
Utility culvert excavation
|
Portion Y
|
Foundation works, sub-structure works and superstructure works for Highway
Operation and Maintenance Area Building
|
Portion Y
|
2.1
Summary of
EM&A Requirements
2.1.1
The EM&A programme requires environmental monitoring
of air quality, noise, water quality, dolphin monitoring and mudflat monitoring
as specified in the approved EM&A Manual.
2.1.2
A summary of Impact EM&A requirements is
presented in Table 2.1. The
locations of air quality, noise and water quality monitoring stations are shown
as in Figure 2.1. The transect line layout in Northwest
and Northeast Lantau Survey Areas is presented in Figure 2.2.
Table 2.1 Summary
of Impact EM&A Requirements
Environmental
Monitoring
|
Description
|
Monitoring
Station
|
Frequencies
|
Remarks
|
Air Quality
|
1-hr TSP
|
AMS 5 & AMS 6
|
At least 3 times every 6 days
|
While the highest dust impact was expected.
|
24-hr TSP
|
At least once every 6 days
|
--
|
Noise
|
Leq (30mins),
L10 (30mins) and
L90 (30mins)
|
NMS5
|
At least once per week
|
Daytime on normal weekdays
(0700-1900 hrs).
|
Water Quality
|
¡P Depth
¡P Temperature
¡P Salinity
¡P Dissolved
Oxygen (DO)
¡P Suspended
Solids (SS)
¡P DO
Saturation
¡P Turbidity
¡P pH
|
¡P Impact
Stations:
IS5, IS(Mf)6, IS7, IS8, IS(Mf)9 & IS10,
¡P Control/Far
Field Stations:
CS2 & CS(Mf)5,
¡P Sensitive
Receiver Stations:
SR3, SR4, SR5, SR10A & SR10B
|
Three times per week
during mid-ebb and mid-flood tides (within ¡Ó 1.75 hour of the predicted time)
|
3
(1 m below water surface,
mid-depth and 1 m above sea bed, except where the water depth is less than 6
m, in which case the mid-depth station may be omitted. Should the water depth be less than 3
m, only the mid-depth station will be monitored).
|
Dolphin
|
Line-transect
Methods
|
Northeast Lantau survey
area and Northwest Lantau survey area
|
Twice per month
|
--
|
Mudflat
|
Horseshoe crabs, seagrass beds, intertidal soft shore communities,
sedimentation rates and water quality
|
San Tau and Tung Chung Bay
|
Once every 3 months
|
--
|
2.2.1
Table 2.2 presents
the Action and Limit Levels for the 1-hour TSP, 24-hour TSP and noise level.
Table 2.2 Action
and Limit Levels for 1-hour TSP, 24-hour TSP and Noise
Environmental Monitoring
|
Parameters
|
Monitoring Station
|
Action Level
|
Limit Level
|
Air
Quality
|
1-hr TSP
|
AMS 5
|
352 µg/m3
|
500 µg/m3
|
AMS 6
|
360 µg/m3
|
24-hr TSP
|
AMS 5
|
164 µg/m3
|
260 µg/m3
|
AMS 6
|
173 µg/m3
|
Noise
|
Leq
(30 min)
|
NMS 5
|
When one documented complaint is received
|
75 dB(A)
|
2.2.2
The Action and Limit
Levels for water quality monitoring are given as in Table 2.3.
Table 2.3 Action
and Limit Levels for Water Quality
Parameter
(unit)
|
Water
Depth
|
Action
Level
|
Limit
Level
|
Dissolved Oxygen (mg/L)
|
Surface and Middle
|
5.0
|
4.2 except 5 for Fish Culture
Zone
|
Bottom
|
4.7
|
3.6
|
Turbidity (NTU)
|
Depth average
|
27.5 or 120% of upstream
control station¡¦s turbidity at the same tide of the same day;
The action level has been
amended to ¡§27.5 and 120% of upstream control station¡¦s turbidity at the same
tide of the same day¡¨ since 25 March 2013.
|
47.0 or 130% of turbidity
at the upstream control station at the same tide of same day;
The limit level has been
amended to ¡§47.0 and 130% of turbidity at the upstream control station at the
same tide of same day¡¨ since 25 March 2013.
|
Suspended Solid (SS)
(mg/L)
|
Depth average
|
23.5 or 120% of upstream
control station¡¦s SS at the same tide of the same day;
The action level has been
amended to ¡§23.5 and 120% of upstream control station¡¦s SS at the same tide of
the same day¡¨ since 25 March 2013.
|
34.4 or 130% of SS at the
upstream control station at the same tide of same day and 10mg/L for Water
Services Department Seawater Intakes;
The limit level has been
amended to ¡§34.4 and 130% of SS at the upstream control station at the same
tide of same day and 10mg/L for Water Services Department Seawater Intakes¡¨
since 25 March 2013
|
Notes:
(1) Depth-averaged
is calculated by taking the arithmetic means of reading of all three depths.
(2) For DO,
non-compliance of the water quality limit occurs when monitoring result is
lower that the limit.
(3) For SS
& turbidity non-compliance of the water quality limits occur when
monitoring result is higher than the limits.
(4) The change
to the Action and limit Levels for Water Quality Monitoring for the EM&A
works was approved by EPD on 25 March 2013. Therefore, the amended Action and
Limit Levels are applied for the water monitoring results obtained on and after
25 March 2013.
2.2.3
The Action and Limit
Levels for dolphin monitoring are shown in Tables
2.4 and 2.5.
Table 2.4 Action
and Limit Level for Dolphin Impact Monitoring
|
North
Lantau Social Cluster
|
NEL
|
NWL
|
Action Level
|
STG < 70% of baseline
&
ANI < 70% of baseline
|
STG < 70% of baseline
&
ANI < 70% of baseline
|
Limit Level
|
STG < 40% of baseline
&
ANI < 40% of baseline
|
Remarks:
(1)
STG means quarterly average encounter rate of
number of dolphin sightings.
(2)
ANI means quarterly average encounter rate of
total number of dolphins.
(3)
For North Lantau Social Cluster, AL will be
triggered if either NEL or NWL fall below the criteria; LL will be triggered if
both NEL and NWL fall below the criteria.
Table 2.5 Derived
Value of Action Level (AL) and Limit Level (LL)
|
North
Lantau Social Cluster
|
NEL
|
NWL
|
Action Level
|
STG < 4.2 & ANI < 15.5
|
STG < 6.9 & ANI
< 31.3
|
Limit Level
|
(STG < 2.4 & ANI
< 8.9) and (STG < 3.9 & ANI < 17.9)
|
Remarks:
(1)
STG means quarterly average encounter rate of
number of dolphin sightings.
(2)
ANI means quarterly average encounter rate of
total number of dolphins.
(3)
For North Lantau Social Cluster, AL will be triggered
if either NEL or NWL fall below the criteria; LL will be triggered if both NEL
and NWL fall below the criteria.
2.3.1 The Event Actions Plans for air quality, noise, water quality and
dolphin monitoring are annexed in Appendix
D.
2.4.1
Environmental
mitigation measures for the contract were recommended in the approved EIA
Report. Appendix E lists the recommended mitigation measures and the
implementation status.
3
Environmental Monitoring and Audit
3.1
Implementation of
Environmental Measures
3.1.1
In response to the site audit findings, the
Contractor have rectified all observations identified in environmental site
inspections undertaken during the reporting period. Details of site audit
findings and the corrective actions during the reporting period are presented
in Appendix
F.
3.1.2
A summary of the Implementation Schedule of
Environmental Mitigation Measures (EMIS) is presented in Appendix E.
3.1.3
Regular marine travel route for
marine vessels were implemented properly in accordance to the submitted plan
and relevant records were kept properly.
3.1.4
Dolphin Watching Plan was
implemented during the reporting period.
No dolphins inside the silt curtain were observed. The relevant records were
kept properly.
3.2.1
The monitoring results for 1-hour TSP and
24-hour TSP are summarized in Tables 3.1 and 3.2
respectively. Detailed impact air quality monitoring results and relevant graphical
plots are presented in Appendix
G.
Table 3.1 Summary
of 1-hour TSP Monitoring Results Obtained During the Reporting Period
Reporting Period
|
Monitoring
Station
|
Average (mg/m3)
|
Range (mg/m3)
|
Action Level (mg/m3)
|
Limit Level (mg/m3)
|
September 2015
|
AMS5
|
95
|
58 - 151
|
352
|
500
|
AMS6
|
97
|
66 - 138
|
360
|
October 2015
|
AMS5
|
123
|
87 - 204
|
352
|
AMS6
|
105
|
73 - 255
|
360
|
November 2015
|
AMS5
|
125
|
65 - 312
|
352
|
AMS6
|
127
|
78 - 316
|
360
|
Table 3.2 Summary
of 24-hour TSP Monitoring Results Obtained During the Reporting Period
Reporting Period
|
Monitoring
Station
|
Average (mg/m3)
|
Range (mg/m3)
|
Action Level (mg/m3)
|
Limit Level (mg/m3)
|
September 2015
|
AMS5
|
36
|
18 - 77
|
164
|
260
|
AMS6
|
61
|
34 - 119
|
173
|
October 2015
|
AMS5
|
51
|
14 - 92
|
164
|
AMS6
|
80
|
27 - 136
|
173
|
November 2015
|
AMS5
|
55
|
37 - 71
|
164
|
AMS6
|
71
|
42 - 93
|
173
|
3.2.2
There were no
Action and Limit Level exceedances of 1-hour TSP and 24-hour TSP were recorded
at AMS5 and AMS6 during the reporting period.
3.3
Noise Monitoring Results
3.3.1
The monitoring results for construction noise
are summarized in Table 3.3 and the
monitoring results and relevant graphical plots for this reporting
period are provided in Appendix H.
Table 3.3 Summary
of Construction Noise Monitoring Results Obtained During the Reporting Period
Reporting period
|
Monitoring
Station
|
Average Leq
(30 mins), dB(A)*
|
Range of Leq
(30 mins), dB(A)*
|
Action Level
|
Limit Level Leq
(30 mins), dB(A)
|
September 2015
|
NMS5
|
56
|
55 ¡V 58
|
When one documented complaint is received
|
75
|
October 2015
|
58
|
58 ¡V 59
|
November 2015
|
60
|
58 ¡V 67
|
3.3.2
There were no Action and Limit Level exceedances for noise during
daytime on normal weekdays of the
reporting period.
3.3.3
Major noise sources during the noise monitoring
included construction activities of the Contract and nearby traffic noise and
insect noise.
3.4.1
Impact water quality monitoring was conducted at
all designated monitoring stations during the reporting period. Impact water quality monitoring results and
relevant graphical plots are provided in
Appendix I.
3.4.2
During the reporting period, ten Action
Level exceedances for suspended solid level were recorded. Record of ¡§Notification
of Environmental Quality Limit Exceedances¡¨ is provided in Appendix M. No exceedance of Limit Level for suspended solid level was recorded. No exceedances of Action and Limit Level for
dissolved oxygen level and turbidity were recorded.
3.4.3
Water quality impact sources during the water
quality monitoring were the construction activities of the Contract, nearby
construction activities by other parties and nearby operating vessels by other
parties.
Data
Analysis
3.5.1
Distribution Analysis ¡V The
line-transect survey data was integrated with the Geographic Information System
(GIS) in order to visualize and interpret different spatial and temporal
patterns of dolphin distribution using sighting positions. Location data of dolphin groups were
plotted on map layers of Hong Kong using a desktop GIS (ArcView© 3.1) to
examine their distribution patterns in details. The dataset was also stratified into
different subsets to examine distribution patterns of dolphin groups with
different categories of group sizes, young calves and activities.
3.5.2
Encounter rate analysis ¡V
Encounter rates of Chinese White Dolphins (number of on-effort sightings per
100 km of survey effort, and total number of dolphins sighted on-effort per 100
km of survey effort) were calculated in NEL and NWL survey areas in relation to
the amount of survey effort conducted during each month of monitoring survey.
Dolphin encounter rates were calculated in two ways for comparisons with the
HZMB baseline monitoring results as well as to AFCD long-term marine mammal
monitoring results.
3.5.3
Firstly, for the comparison
with the HZMB baseline monitoring results, the encounter rates were calculated
using primary survey effort alone, and only data collected under Beaufort 3 or
below condition would be used for encounter rate analysis. The average encounter rate of sightings
(STG) and average encounter rate of dolphins (ANI) were deduced based on the
encounter rates from six events during the present quarter (i.e. six sets of
line-transect surveys in North Lantau), which was also compared with the one
deduced from the six events during the baseline period (i.e. six sets of
line-transect surveys in North Lantau).
3.5.4
Secondly, the encounter rates
were calculated using both primary and secondary survey effort collected under
Beaufort 3 or below condition as in AFCD long-term monitoring study. The encounter rate of sightings and
dolphins were deduced by dividing the total number of on-effort sightings and
total number of dolphins (ANI) by the amount of survey effort for the present
quarterly period.
3.5.5
Quantitative grid analysis on
habitat use ¡V To conduct quantitative grid analysis of habitat use, positions
of on-effort sightings of Chinese White Dolphins collected during the quarterly
impact phase monitoring period were plotted onto 1-km2 grids among
Northwest Lantau (NWL) and Northeast (NEL) survey areas on GIS. Sighting densities (number of on-effort
sightings per km2) and dolphin densities (total number of dolphins
from on-effort sightings per km2) were then calculated for each 1 km
by 1 km grid with the aid of GIS.
Sighting density grids and dolphin density grids were then further
normalized with the amount of survey effort conducted within each grid. The total amount of survey effort spent
on each grid was calculated by examining the survey coverage on each
line-transect survey to determine how many times the grid was surveyed during
the study period. For example, when
the survey boat traversed through a specific grid 50 times, 50 units of survey
effort were counted for that grid.
With the amount of survey effort calculated for each grid, the sighting
density and dolphin density of each grid were then normalized (i.e. divided by
the unit of survey effort).
3.5.6
The newly-derived unit for
sighting density was termed SPSE, representing the number of on-effort
sightings per 100 units of survey effort.
In addition, the derived unit for actual dolphin density was termed
DPSE, representing the number of dolphins per 100 units of survey effort. Among the 1-km2 grids that
were partially covered by land, the percentage of sea area was calculated using
GIS tools, and their SPSE and DPSE values were adjusted accordingly. The following formulae were used to
estimate SPSE and DPSE in each 1-km2 grid within the study area:
SPSE = ((S / E) x 100) /
SA%
DPSE = ((D / E) x 100) /
SA%
where S =
total number of on-effort sightings
D = total number of
dolphins from on-effort sightings
E = total number of units
of survey effort
SA% = percentage of sea
area
3.5.7
Behavioural analysis ¡V When
dolphins were sighted during vessel surveys, their behaviour was observed. Different activities were categorized
(i.e. feeding, milling/resting, traveling, socializing) and recorded on
sighting datasheets. This data was
then input into a separate database with sighting information, which can be
used to determine the distribution of behavioural data with a desktop GIS. Distribution of sightings of dolphins
engaged in different activities and behaviours would then be plotted on GIS and
carefully examined to identify important areas for different activities of the
dolphins.
3.5.8
Ranging pattern analysis ¡V
Location data of individual dolphins that occurred during the 3-month baseline
monitoring period were obtained from the dolphin sighting database and
photo-identification catalogue. To
deduce home ranges for individual dolphins using the fixed kernel methods, the
program Animal Movement Analyst Extension, was loaded as an extension with
ArcView© 3.1 along with another extension Spatial Analyst 2.0. Using the fixed kernel method, the
program calculated kernel density estimates based on all sighting positions,
and provided an active interface to display kernel density plots. The kernel estimator then calculated and
displayed the overall ranging area at 95% UD level.
Summary
of Survey Effort and Dolphin Sightings
3.5.9
During the period of September to November
2015, six sets of systematic line-transect vessel surveys were conducted to
cover all transect lines in NWL and NEL survey areas twice per month.
3.5.10
From these surveys, a total of 902.25 km of survey effort was collected, with 95.0% of the total survey effort being conducted under favourable weather
conditions
(i.e. Beaufort Sea State 3 or below with good visibility). Among the two areas, 346.64 km and 555.61 km of survey effort were
conducted in NEL and NWL survey areas respectively.
3.5.11
The total survey effort conducted on
primary lines 656.41 km, while the effort on secondary lines was 245.84 km. Survey effort conducted on both primary and secondary lines
were considered as on-effort survey data.
A summary table of the survey
effort is shown in Annex I of Appendix
J.
3.5.12
During the six sets of monitoring surveys
in September-November 2015, a total of 18 groups of 95 Chinese White Dolphins were sighted. A summary table of the dolphin sightings is shown in Annex
II of Appendix J.
3.5.13 For the present quarterly period, all dolphin sightings were made during on-effort search, and all
except one dolphin sighting were made on primary lines. Moreover, all
dolphin groups were sighted in NWL, while none was sighted at all in NEL. In fact, since July 2014, only one sighting of a lone dolphin was
made in NEL during HKLR03 monitoring surveys.
Distribution
3.5.14 Distribution of dolphin sightings made during monitoring surveys in
September to November 2015 is shown in Figure 1 of Appendix J. Dolphin sightings made in the present quarter were mostly
clustered around Lung Kwu Chau (Figure 1
of Appendix J). A few other
sightings were also made near Sha Chau and to the west of the airport platform
(Figure 1 of Appendix J).
3.5.15
Notably, all dolphin sightings
were made far away from the HKLR03/HKBCF reclamation sites as well as along the
entire alignment of Tuen Mun-Chek Lap Kok Link (TMCLKL) during the present
quarterly period (Figure 1
of Appendix J). On the other hand, two sightings with five dolphins were
made in the vicinity of the HKLR09 alignment (Figure 1 of Appendix J).
3.5.16
Sighting distribution of the
present impact phase monitoring period (September to November 2015) was
compared to the one during the baseline monitoring period (September to
November 2011). In the present
quarter, dolphins have disappeared from the NEL region, which was in stark
contrast to their frequent occurrence around the Brothers Islands, near Shum
Shui Kok and in the vicinity of HKBCF reclamation site during the baseline
period (Figure 1 of Appendix J). The nearly complete abandonment of NEL
region by the dolphins has been consistently recorded in the past eleven
quarters of HKLR03 monitoring, which has resulted in zero
to extremely low dolphin
encounter rate in this area.
3.5.17
In NWL survey area, dolphin occurrence was
also drastically different between the baseline and impact phase periods. During the present impact monitoring
period, fewer dolphins occurred in this survey area
than during the baseline period, when many of the dolphin sightings were
concentrated between Lung Kwu Chau and Black Point, around Sha Chau, near
Pillar Point and to the west of the Chek
Lap Kok
Airport (Figure
1 of Appendix J).
3.5.18
Another comparison in dolphin
distribution was made between the three quarterly periods of autumn months in
2013, 2014 and 2015 (Figure 2 of Appendix J). Among the three autumn periods, no dolphin
was sighted at all in NEL in both 2014 and 2015, while two sightings were made
there in 2013 (Figure 2 of Appendix J).
3.5.19
On the other hand, dramatic
changes in dolphin distribution in NWL waters were also observed in the autunm
months during the three-year period (Figure 2 of
Appendix J).
In 2013, dolphins regularly occurred throughout the NWL survey area,
with higher concentrations of sightings around Sha Chau, Lung Kwu Chau, near
Black Point and Pillar Point. In
2014, dolphins still frequently occurred around Sha Chau and Lung Kwu Chau, but
less frequently in the middle portion of the North Lantau
region. In 2015, they infrequently
occurred in NWL survey area with the only concentration of sightings around
Lung Kwu Chau, while they generally absent for the rest of this area. Similar temporal changes in dolphin
distribution were also observed in the spring and summer periods of
2013-15. The temporal trend indicated
that dolphin usage in the NWL region has progressively diminished in recent
years.
Encounter Rate
3.5.20
During the present three-month
study period, the encounter rates of Chinese White Dolphins deduced from the
survey effort and on-effort sighting data from the primary transect lines under
favourable conditions (Beaufort 3 or below) for each set of the surveys in NEL
and NWL are shown in Table 3.4.
The average encounter rates deduced from the six
sets of surveys were also compared with the ones deduced from the baseline
monitoring period (September ¡V November 2011) (See Table
3.5).
Table
3.4 Dolphin
Encounter Rates (Sightings Per 100 km of Survey Effort) During Reporting Period
(September to November 2015)
Survey Area
|
Dolphin Monitoring
|
Encounter rate (STG)
(no. of on-effort dolphin sightings per 100 km of survey effort)
|
Encounter rate (ANI)
(no. of dolphins from all on-effort sightings per 100 km of survey effort)
|
Primary Lines Only
|
Primary Lines Only
|
Northeast Lantau
|
Set 1 (2 & 11 Sep 2015)
|
0.00
|
0.00
|
Set 2 (17 & 29 Sep 2015)
|
0.00
|
0.00
|
Set 3 (6 & 13 Oct 2015)
|
0.00
|
0.00
|
Set 4 (19 & 26 Oct 2015)
|
0.00
|
0.00
|
Set 5 (2 & 6 Nov 2015)
|
0.00
|
0.00
|
Set 6 (10 & 16 Nov 2015)
|
0.00
|
0.00
|
Northwest Lantau
|
Set 1 (2 & 11 Sep 2015)
|
5.47
|
51.95
|
Set 2 (17 & 29 Sep 2015)
|
4.01
|
21.38
|
Set 3 (6 & 13 Oct 2015)
|
5.86
|
24.91
|
Set 4 (19 & 26 Oct 2015)
|
2.73
|
10.94
|
Set 5 (2 & 6 Nov 2015)
|
3.84
|
15.38
|
Set 6 (10 & 16 Nov 2015)
|
1.73
|
1.73
|
Table 3.5 Comparison of average dolphin encounter rates from impact monitoring
period (September to November 2015) and baseline monitoring period (September ¡V
November 2011)
Survey Area
|
Encounter rate (STG)
(no. of on-effort dolphin sightings per 100 km of survey effort)
|
Encounter rate (ANI)
(no. of dolphins from all on-effort sightings per 100 km of survey effort)
|
Reporting Period
|
Baseline Monitoring Period
|
Reporting Period
|
Baseline Monitoring Period
|
Northeast Lantau
|
0.0
|
6.00 ¡Ó 5.05
|
0.0
|
22.19 ¡Ó 26.81
|
Northwest Lantau
|
3.94 ¡Ó 1.57
|
9.85 ¡Ó 5.85
|
21.05 ¡Ó 17.19
|
44.66 ¡Ó 29.85
|
Notes:
1) The encounter rates deduced from the baseline monitoring period have been
recalculated based only on the survey effort and on-effort sighting data made
along the primary transect lines under favourable conditions.
2) ¡Ó denotes the standard deviation of the average
encounter rates.
3.5.21
To facilitate the comparison
with the AFCD long-term monitoring results, the encounter rates were also calculated
for the present quarter using both primary and secondary survey effort. The encounter rates of sightings (STG)
and dolphins (ANI) in NWL were 3.31 sightings and 17.52 dolphins per 100 km of
survey effort respectively, while the encounter rates of sightings (STG) and
dolphins (ANI) in NEL were both nil for this
quarter.
3.5.22
In NEL, the average dolphin
encounter rates (both STG and ANI) in the present three-month impact monitoring
period were zero with no sighting made, and such low occurrence of dolphins in
NEL have been consistently recorded in the past eleven quarters of HKLR03
monitoring (Table 3.6). This is a serious concern as
the dolphin occurrence in NEL in the last eleven quarters (0.0-1.0 for ER(STG)
and 0.0-3.9 for ER(ANI)) have been exceptionally low when compared to the
baseline period (Table 3.6). Dolphins have almost vacated from NEL
waters since January 2014, with only two groups of five dolphins sighted there
since then despite consistent and intensive survey effort being conducted in this
survey area.
Table
3.6 Comparison of Average
Dolphin Encounter Rates in Northeast Lantau Survey Area from All Quarters of
Impact Monitoring Period and Baseline Monitoring Period (Sep ¡V Nov 2011)
Monitoring Period
|
Encounter rate (STG)
(no. of on-effort dolphin sightings per 100 km of survey effort)
|
Encounter rate (ANI)
(no. of dolphins from all on-effort sightings per 100 km of survey effort)
|
September-November 2011
(Baseline)
|
6.00 ¡Ó 5.05
|
22.19 ¡Ó 26.81
|
December 2012-February
2013 (Impact)
|
3.14 ¡Ó 3.21
|
6.33 ¡Ó 8.64
|
March-May
2013 (Impact)
|
0.42 ¡Ó 1.03
|
0.42 ¡Ó 1.03
|
June-August
2013 (Impact)
|
0.88 ¡Ó 1.36
|
3.91 ¡Ó 8.36
|
September-November
2013 (Impact)
|
1.01 ¡Ó 1.59
|
3.77 ¡Ó 6.49
|
December 2013-February
2014 (Impact)
|
0.45 ¡Ó 1.10
|
1.34 ¡Ó 3.29
|
March-May
2014 (Impact)
|
0.00
|
0.00
|
June-August
2014 (Impact)
|
0.42 ¡Ó 1.04
|
1.69 ¡Ó 4.15
|
September-November
2014 (Impact)
|
0.00
|
0.00
|
December
2014-February 2015 (Impact)
|
0.00
|
0.00
|
March-May
2015 (Impact)
|
0.00
|
0.00
|
June
¡V August 2015 (Impact)
|
0.44 ¡Ó 1.08
|
0.44 ¡Ó 1.08
|
September-November 2015 (Impact)
|
0.00
|
0.00
|
Notes:
1) The encounter rates deduced from the baseline monitoring period have been recalculated
based only on survey effort and on-effort sighting data made along the primary
transect lines under favourable conditions.
2) ¡Ó denotes the standard deviation of the average encounter rates.
3.5.23
Moreover, the average dolphin encounter rates (STG and ANI) in NWL
during the present impact phase monitoring period were also much lower (reductions of 60.0% and 52.9% respectively) than the ones recorded
in the 3-month baseline period, indicating a dramatic decline in dolphin usage
of this survey area as well during the present impact phase period (Table 3.7).
3.5.24
Even for the same autumn quarters, the dolphin encounter rates in NWL
during autumn 2015 were much lower than the ones recorded in autumn 2013 and
2014 (Table 3.7).
3.5.25
It should be noted that the encounter
rates in NWL in the present quarter have slightly rebounded from the
exceptionally low level in the previous three quarters (Table 3.7). Such
potential rebound in dolphin occurrence could be an encouraging sign, and
should be continuously monitored in the upcoming monitoring quarters.
Table 3.7 Comparison of Average Dolphin Encounter Rates in Northwest Lantau
Survey Area from All Quarters of Impact Monitoring Period and Baseline
Monitoring Period (Sep ¡V Nov 2011)
Monitoring Period
|
Encounter rate
(STG)
(no. of on-effort
dolphin sightings per 100 km of survey effort)
|
Encounter rate
(ANI)
(no. of dolphins from all on-effort sightings per 100 km of survey
effort)
|
September-November 2011 (Baseline)
|
9.85 ¡Ó 5.85
|
44.66 ¡Ó 29.85
|
December 2012-February
2013 (Impact)
|
8.36 ¡Ó 5.03
|
35.90 ¡Ó 23.10
|
March-May 2013 (Impact)
|
7.75 ¡Ó 3.96
|
24.23 ¡Ó 18.05
|
June-August 2013 (Impact)
|
6.56 ¡Ó 3.68
|
27.00 ¡Ó 18.71
|
September-November 2013 (Impact)
|
8.04 ¡Ó 1.10
|
32.48 ¡Ó 26.51
|
December 2013-February
2014 (Impact)
|
8.21 ¡Ó 2.21
|
32.58 ¡Ó 11.21
|
March-May 2014 (Impact)
|
6.51 ¡Ó 3.34
|
19.14 ¡Ó 7.19
|
June-August 2014 (Impact)
|
4.74 ¡Ó 3.84
|
17.52 ¡Ó 15.12
|
September-November 2014 (Impact)
|
5.10 ¡Ó 4.40
|
20.52 ¡Ó 15.10
|
December 2014-February
2015 (Impact)
|
2.91 ¡Ó 2.69
|
11.27 ¡Ó 15.19
|
March-May 2015
(Impact)
|
0.47 ¡Ó 0.73
|
2.36 ¡Ó 4.07
|
June ¡V August 2015
(Impact)
|
2.53 ¡Ó 3.20
|
9.21 ¡Ó 11.57
|
September-November 2015 (Impact)
|
3.94 ¡Ó 1.57
|
21.05 ¡Ó 17.19
|
Notes:
1) The encounter rates deduced from the
baseline monitoring period have been recalculated based only on survey effort
and on-effort sighting data made along the primary transect lines under
favourable conditions.
2) ¡Ó denotes the standard deviation of the average encounter rates.
3.5.26 As discussed recently in Hung (2015), the dramatic decline in
dolphin usage of NEL waters in the past few years (including the declines in
abundance, encounter rate and habitat use in NEL, as well as shifts of
individual core areas and ranges away from NEL waters) was possibly related to
the HZMB construction works that were commenced since 2012. It appeared that such noticeable decline
has already extended to NWL waters progressively in 2013 to 2015.
3.5.27
A two-way ANOVA with repeated measures and
unequal sample size was conducted to examine whether there were any significant
differences in the average encounter rates between the baseline and impact
monitoring periods. The two
variables that were examined included the two periods (baseline and impact
phases) and two locations (NEL and NWL).
3.5.28
For the comparison between the
baseline period and the present quarter (twelfth quarter of the impact phase
being assessed), the p-values for the differences in average dolphin encounter rates
of STG and ANI were 0.0079 and 0.071 respectively. If the alpha value is set at 0.05,
significant differences were detected between the baseline and present quarters
in the dolphin encounter rate of STG, but not in the dolphin encounter rate of
ANI.
3.5.29 For the
comparison between the baseline period and the cumulative quarters in impact
phase (i.e first twelve quarters of the impact phase
being assessed), the p-values for the differences in average dolphin encounter
rates of STG and ANI were 0.00009 and 0.00003 respectively. Even if the alpha value is set at
0.0001, significant differences were still detected in both the average dolphin
encounter rates of STG and ANI (i.e. between the two periods and the locations).
3.5.30 As
indicated in both dolphin distribution patterns and encounter rates, dolphin
usage has been significantly reduced in both NEL and NWL survey areas during
the present quarterly period, and such low occurrence of dolphins has also been
consistently documented in previous quarters. This
raises serious concern, as the timing of the decline in dolphin usage in North
Lantau waters coincided well with the construction schedule of the HZMB-related
projects (Hung 2015).
3.5.31
To ensure the continuous
usage of North Lantau waters by the dolphins, every possible measure should be
implemented by the contractors and relevant authorities of HZMB-related works
to minimize all disturbances to the dolphins.
Group
Size
3.5.32
Group size of Chinese White Dolphins ranged from
one to twelve individuals per group in North Lantau region during September to
November 2015. The average dolphin
group sizes from these three months were compared with the ones deduced from
the baseline period in September to November 2011, as shown in Table 3.8.
Table 3.8 Comparison
of Average Dolphin Group Sizes between Reporting Period (Sep ¡V Nov 2015) and
Baseline Monitoring Period (Sep ¡V Nov 2011)
Survey Area
|
Average Dolphin Group Size
|
Reporting Period
|
Baseline Monitoring Period
|
Overall
|
5.28 ¡Ó 3.54 (n = 18)
|
3.72 ¡Ó 3.13 (n = 66)
|
Northeast Lantau
|
N/A
|
3.18 ¡Ó 2.16 (n = 17)
|
Northwest Lantau
|
5.28 ¡Ó 3.54 (n = 18)
|
3.92 ¡Ó 3.40 (n = 49)
|
Note:
1) ¡Ó denotes the standard deviation of the average group size.
3.5.33
The average dolphin group sizes in NWL waters during
September to November 2015 was higher than the ones recorded during the
three-month baseline period (Table 3.8). Seven of the 18 groups were composed
of 1-3 individuals only, while five other groups were moderate in size with 4-6
individuals per group. Moreover,
six large dolphin groups were sighted during the present quarterly period,
including three groups with 7-9 individuals each, and another three groups with
10-12 individuals each.
3.5.34
Distribution of dolphins with
larger group sizes (five individuals or more per group and ten individuals per
group) during the present quarter is shown in Figure 3 of Appendix J, with comparison to the one in baseline
period. During the autumn months of
2015, distribution of these large groups of dolphins were all located around
Lung Kwu Chau and Sha Chau, with the three exceptionally large groups of
dolphins (i.e. with 10 or more individuals) sighted adjacent to Lung Kwu Chau (Figure 3 of Appendix J). This
distribution pattern was very different from the baseline period, when the
larger dolphin groups were distributed more evenly in NWL waters with a few
more sighted in NEL waters (Figure 3 of
Appendix J).
Habitat Use
3.5.35
From September to November 2015, the only area being heavily utilized by Chinese White Dolphins was around and to the
north of Lung Kwu Chau, as well as both eastern and western sides of Sha Chau
in North Lantau region (Figures 4a and 4b of Appendix J). All grids
near HKLR03/HKBCF reclamation sites as well as TMCLKL alignment did not record
any presence of dolphins during on-effort search in the present quarterly
period, but one grid (F19) in the vicinity of HKLR09 alignment recorded
moderately high dolphin densities (Figures
4b of Appendix J).
3.5.36
It should be emphasized that the amount of survey effort collected in
each grid during the three-month period was fairly low (6-12 units of survey
effort for most grids), and therefore the habitat use pattern derived from the
three-month dataset should be treated with caution. A more complete picture of dolphin
habitat use pattern should be examined when more survey effort for each grid will be collected throughout
the impact phase monitoring programme.
3.5.37
When compared with the habitat
use patterns during the baseline period, dolphin usage in NEL and NWL has
dramatically diminished in both areas during the present impact monitoring
period (Figure 5 of Appendix J). During the baseline period, many grids
between Siu Mo To and Shum Shui Kok recorded moderately high to high dolphin
densities, which was in stark contrast to the complete absence of dolphins
there during the present impact phase period (Figure 5 of Appendix J).
3.5.38
The density patterns were also
very different in NWL between the baseline and impact phase monitoring periods,
with higher dolphin usage around Sha Chau, near Black Point, to the west of the
airport, as well as between Pillar Point and airport platform during the
baseline period. In contrast, only
the waters around Lung Kwu Chau and Sha Chau recorded high densities of
dolphins during the present impact phase period (Figure 5 of Appendix J).
Mother-calf Pairs
3.5.39
During the present quarterly period,
two young calves (i.e. unspotted calf or unspotted juvenile) were spotted with
their mothers near Lung Kwu Chau
3.5.40
The rare occurrence of young
calves in the present quarter was in stark contrast to their regular occurrence
in North Lantau waters during the baseline
period. This should be of a serious
concern, and the occurrence of young calves in North
Lantau waters should be closely monitored in the upcoming
quarters.
Activities
and Associations with Fishing Boats
3.5.41
Four of the 18 dolphin groups
were engaged in feeding activities, while two other dolphin groups were engaged
in socializing
activities. None of the dolphin
groups were engaged in traveling or milling/resting activity during the three-month study period.
3.5.42
The percentages of sightings
associated with feeding activities (22.2%) and socializing activities (11.1%)
during the present impact phase period were both higher than the ones recorded
during the baseline period (11.6% and 5.4% respectively). However, it should be noted the sample
sizes on total numbers of dolphin sightings were very different between the two
periods
3.5.43
Distribution of dolphins engaged in various activities during the
present three-month period and baseline period is shown
in Figure 6 of Appendix J. The four dolphin groups engaged in
feeding activities were sighted near Lung Kwu Chau and Sha Chau as well as to
the north of Lung Kwu Chau (Figure 6 of Appendix J). The two groups engaged in socializing
activities were both located to the west of Lung Kwu Chau (Figure 6 of Appendix J).
3.5.44
When compared to the baseline
period, distribution of various dolphin activities during the present impact
phase monitoring period was drastically different with a much more restricted
area of occurrences.
3.5.45
As consistently recorded in the
past monitoring quarters, none
of the 18 dolphin groups was found to be associated with operating
fishing vessels in North Lantau waters during the present impact phase period.
Summary Photo-identification
works
3.5.46
From September to November
2015, over 2,500 digital photographs of Chinese White Dolphins were taken
during the impact phase monitoring surveys for the photo-identification work.
3.5.47
In total, 34 individuals
sighted 65 times altogether were identified (see summary table in Annex III of Appendix J and photographs
of identified individuals in Annex IV of
Appendix J). All of these
re-sightings were made in NWL.
3.5.48
The majority of identified
individuals were sighted only once or twice during the three-month period, with
the exception of two individuals (NL46 and NL210) being 3-4 times and another
three individuals (NL48, NL202 and NL286) being sighted 5-6 times.
3.5.49
Notably, eight of these 34
individuals (NL33, NL123, NL284, NL285, WL05, WL79, WL241 and WL243) were also
sighted in West Lantau waters during the
HKLR09 monitoring surveys from September to November 2015, implying that they
have moved across the HKLR09 bridge alignment during the same three-month
period.
Individual
range use
3.5.50
Ranging patterns of the 34 individuals identified during the three-month
study period were determined by fixed kernel method, and are shown in Annex V of Appendix J.
3.5.51
All identified dolphins sighted
in the present quarter were utilizing NWL waters only, but have completely
avoided NEL waters where many of them have utilized as their core areas in the
past Annex V of Appendix J). This
is in contrary to the extensive movements between NEL and NWL survey areas
observed in the earlier impact monitoring quarters as well as the baseline
period.
3.5.52
Notably, several individuals
(NL33, NL123, NL284, NL285 and WL05) consistently utilized both NWL and NEL
waters in the past have extended their range use to WL waters (and even SWL
waters in the case of NL33) during the present quarter. In the upcoming quarters, individual
range use and movements should be continuously monitored to examine whether
there has been any consistent shifts of individual home ranges from North
Lantau to West or Southwest Lantau, as such shift could possibly be related to
the HZMB-related construction works (see Hung 2015).
Action Level / Limit Level Exceedance
3.5.53
There was two Action Level exceedances of dolphin
monitoring for the quarterly monitoring data (between September - November
2015). According to the contractor¡¦s information, the marine activities
undertaken for HKLR03 during the quarter of September to November 2015 included
reclamation, excavation of stone platform,
construction of seawall, temporary drainage diversion and ground investigation.
There is no evidence showing the
current AL non-compliance directly related to the construction works of HKLR03 (where
the amounts of working vessels for HKLR03 have been decreasing), although the generally increased amount of
vessel traffic in NEL since the impact phase (October 2012). It should also be noted
that reclamation work under HKLR03 (adjoining the Airport Island) situates in
waters which has rarely been used by dolphins in the past, and the working
vessels under HKLR03 have been travelling from source to destination in
accordance with the Marine Travel Route to minimize impacts on Chinese White
Dolphin. In addition, the
contractor will implement proactive mitigation measures such as avoiding
anchoring at Marine Department¡¦s designated anchorage site ¡V Sham Shui Kok
Anchorage (near Brothers Island) as far as practicable.
3.5.54 A two-way ANOVA with repeated measures and unequal
sample size was conducted to examine whether there were any significant
differences in the average encounter rates between the baseline and impact
monitoring periods. The two variables
that were examined included the two periods (baseline and impact phases) and
two locations (NEL and NWL).A).
3.5.55
For the comparison
between the baseline period and the present quarter (12th quarter of
the impact phase being assessed), the p-value for the differences in average
dolphin encounter rates of STG and ANI were 0.0079 and 0.071 respectively. If the alpha value is set at 0.05,
significant differences were detected between the baseline and present quarters
in dolphin encounter rate of STG, but not in the dolphin encounter rate of ANI.
3.5.56
For the
comparison between the baseline period and the cumulative quarters in impact
phase (i.e. first twelve quarters of the impact phase being assessed), the p-value
for the differences in average dolphin encounter rates of STG and ANI were
0.00009 and 0.00003 respectively.
Even if the alpha value is set at 0.001, significant differences were
detected in both the average dolphin encounter rates of STG and ANI (i.e.
between the two periods and the locations).
3.5.57
The AFCD
monitoring data during September 2015 to November 2015 has been reviewed by the
dolphin specialist. During the same
quarter, no dolphin was sighted from 78.70 km of survey effort on primary lines
in NEL, while seven groups of 24 dolphins were sighted from 144.11 km of survey
effort on primary lines in NWL.
This review has confirmed that the low occurrence of dolphins reported
by the HKLR03 monitoring surveys in autumn 2015 in NEL and NWL survey area is accurate.
3.5.58
All dolphin protective
measures are fully and properly implemented in accordance with the EM&A
Manual. According to the Marine Travel Route Plan, if vessels are crossing
along edge of the proposed marine park, the travelling speed will keep not
exceeding 5 knots when crossing the edge of the proposed marine park. The
Contractor will continue to provide training for skippers to ensure that their
working vessels travel from source to destination to minimize impacts on
Chinese White Dolphin and avoid anchoring at Marine Department¡¦s designated
anchorage site - Sham Shui Kok Anchorage (near Brothers Island) as far as
practicable. Also, it is
recommended to complete the marine works of the Contract as soon as possible so as to reduce the
overall duration of impacts and allow the dolphins population to recover as
early as possible.
3.5.59
A meeting was held on 15
January 2016 with attendance of representative of Highways Department (HyD),
ENPO, Resident Site Staff (RSS), Environmental Team (ET) and dolphin specialist
for Contract Nos. HY/2010/02, HY/2011/03, HY/2012/07, HY/2012/08. Also, main
Contractor for Contract Nos. HY/2012/07 and HY/2012/08 attended the meeting.
The discussion/recommendation as recorded in the minutes of the meeting, which
might be relevant to HKLR03 Contract are summarized below.
3.5.60 It was concluded that the HZMB works is one of the
contributing factors affecting the dolphins. It was also concluded the
contribution of impacts due to the HZMB works as a whole (or individual marine
contracts) cannot be quantified nor separate from the other stress factors.
3.5.61 It was reminded that the ETs shall keep reviewing
the implementation status of the dolphin related mitigation measures and remind
the contractor to ensure the relevant measures were fully implemented.
3.5.62 It was recommended that the marine works of HZMB
projects should be completed as soon as possible so as to reduce the overall
duration of impacts and allow the dolphins population to recover as early as
possible.
3.5.63 It was also recommended that the marine works
footprint (e.g., reduce the size of peripheral silt curtain) and vessels for
the marine works should be reduced as much as possible, and vessels idling /
mooring in other part of the North Lantau shall be avoided whenever possible.
3.5.64 It was suggested that the protection measures (e.g.,
speed limit control) for the proposed Brothers Island Marine Park (BMP) shall
be brought forward as soon as possible before its establishment so as to
provide a better habitat for dolphin recovery. It was noted that under the
Regular Marine Travel Route Plan, the contractors have committed to reduce the
vessel speed in BMP. HyD updated that the proposed BMP will be gazetted in
January 2016. The ETs were reminded to update the BMP boundary in the Regular
Marine Travel Route Plan.
3.5.65
There was a discussion on
exploring possible further mitigation measures, for example, controlling the
underwater noise. It was noted that the EIA reports for the projects suggested
several mitigation measures, all of which have been implemented.
3.6
Mudflat Monitoring Results
Sedimentation
Rate Monitoring
3.6.1
The baseline sedimentation rate
monitoring was in September 2012 and impact sedimentation rate monitoring was
undertaken on 10
September 2015. The mudflat surface levels at the four
established monitoring stations and the corresponding XYZ HK1980 GRID
coordinates are presented in Table 3.9 and Table 3.10.
Table 3.9 Measured
Mudflat Surface Level Results
|
Baseline Monitoring
(September 2012)
|
Impact Monitoring
(September 2015)
|
Monitoring Station
|
Easting
(m)
|
Northing (m)
|
Surface Level
(mPD)
|
Easting
(m)
|
Northing (m)
|
Surface Level
(mPD)
|
S1
|
810291.160
|
816678.727
|
0.950
|
810291.167
|
816678.723
|
1.061
|
S2
|
810958.272
|
815831.531
|
0.864
|
810958.278
|
815831.542
|
0.960
|
S3
|
810716.585
|
815953.308
|
1.341
|
810716.595
|
815953.340
|
1.466
|
S4
|
811221.433
|
816151.381
|
0.931
|
811221.414
|
816151.336
|
1.004
|
Table 3.10 Comparison
of Measurement
|
Comparison of measurement
|
Remarks and Recommendation
|
Monitoring Station
|
Easting
(m)
|
Northing (m)
|
Surface Level
(mPD)
|
S1
|
0.007
|
-0.004
|
0.111
|
Level
continuously increased
|
S2
|
0.006
|
0.011
|
0.096
|
Level
continuously increased
|
S3
|
0.010
|
0.032
|
0.125
|
Level
continuously increased
|
S4
|
-0.019
|
-0.045
|
0.073
|
Level
continuously increased
|
3.6.2
This measurement result was generally and relatively higher than the
baseline measurement at S1, S2,
S3 and S4. The mudflat level is continuously increased.
Water
Quality Monitoring
3.6.3
The mudflat monitoring covered water quality
monitoring data. Reference was made
to the water quality monitoring data of the representative water quality
monitoring station (i.e. SR3) as in the EM&A Manual. The water quality monitoring location
(SR3) is shown in Figure 2.1.
3.6.4 Impact
water quality monitoring in San Tau (monitoring station SR3) was conducted in
September 2015. The monitoring parameters included dissolved oxygen (DO),
turbidity and suspended solids (SS).
3.6.5 The
Impact monitoring result for SR3 were extracted and summarised below:
Table 3.11 Impact
Water Quality Monitoring Results (Depth Average)
Date
|
Mid Ebb Tide
|
Mid Flood Tide
|
DO (mg/L)
|
Turbidity
(NTU)
|
SS (mg/L)
|
DO (mg/L)
|
Turbidity
(NTU)
|
SS (mg/L)
|
2-Sep-15
|
5.69
|
20.40
|
8.30
|
5.46
|
15.85
|
13.50
|
4-Sep-15
|
6.27
|
7.55
|
7.35
|
6.22
|
4.40
|
4.60
|
7-Sep-15
|
6.32
|
3.75
|
3.30
|
6.43
|
4.75
|
5.80
|
9-Sep-15
|
6.89
|
4.65
|
2.95
|
7.75
|
4.80
|
4.10
|
11-Sep-15
|
6.53
|
5.95
|
5.35
|
9.00
|
7.20
|
6.80
|
14-Sep-15
|
5.82
|
6.75
|
6.50
|
5.74
|
5.35
|
7.00
|
16-Sep-15
|
5.86
|
10.70
|
11.90
|
5.64
|
7.50
|
7.70
|
18-Sep-15
|
5.82
|
8.50
|
7.50
|
5.71
|
6.70
|
6.20
|
21-Sep-15
|
6.07
|
6.30
|
5.30
|
6.58
|
3.80
|
2.70
|
23-Sep-15
|
6.15
|
3.80
|
2.45
|
7.39
|
3.30
|
2.60
|
25-Sep-15
|
6.63
|
5.20
|
5.90
|
8.23
|
10.05
|
5.20
|
28-Sep-15
|
5.27
|
7.65
|
7.90
|
6.04
|
8.05
|
8.55
|
30-Sep-15
|
5.64
|
17.15
|
13.75
|
5.47
|
12.45
|
16.00
|
Average
|
6.07
|
8.33
|
6.80
|
6.59
|
7.25
|
6.98
|
Mudflat Ecology Monitoring
Sampling
Zone
3.6.6
In order to collect baseline
information of mudflats in the study site, the study site was divided into three sampling zones (labeled as TC1, TC2, TC3) in Tung Chung Bay and one zone in San Tau (labeled as ST) (Figure 2.1 of Appendix O). The horizontal length of
sampling zones TC1, TC2, TC3 and ST were about 250 m, 300 m, 300 m and 250 m,
respectively. Survey of horseshoe crabs, seagrass beds and intertidal
communities were conducted in every sampling zone. The present survey was conducted in September 2015 (totally 5 sampling days between 5th and 13th September 2015The
locations of sampling zones are shown in Annex
I of Appendix O.
Horseshoe
Crabs
3.6.7
Active search method was conducted for
horseshoe crab monitoring by two experienced surveyors at every sampling
zone. During the search period, any accessible and
potential area would be investigated for any horseshoe crab individuals within
2-3 hours in low tide period (tidal level
below 1.2 m above Chart Datum (C.D.)). Once a horseshoe crab individual was found, the
species was identified referencing to Li (2008). The prosomal
width, inhabiting substratum and respective
GPS coordinate were recorded. A photographic
record was taken for
future investigation. Any
grouping behavior of individuals, if found, was recorded. The horseshoe crab surveys were conducted on 6th (for TC1),
10th (for TC3 and ST) and 12th (for TC2) September 2015.
During the survey period, the weather was hot and sunny in TC1, TC3 and ST
while it was rainy in TC2.
Seagrass Beds
3.6.8
Active search method was conducted for seagrass bed monitoring
by two experienced surveyors at every sampling zone. During the search period, any
accessible and potential area would be investigated for any seagrass beds
within 2-3 hours in low tide period. Once seagrass
bed was found, the species, estimated area, estimated coverage percentage and respective GPS coordinate were recorded. A photographic
record was taken for
future investigation. The seagrass beds surveys were
conducted on 6th (for TC1), 10th (for TC3 and ST) and 12th
(for TC2) September 2015. During the survey period, the weather was hot and
sunny in TC1, TC3 and ST while it was rainy in TC2.
Intertidal Soft Shore
Communities
3.6.9 The intertidal soft shore
community surveys were conducted in low tide period on 5th (for ST),
6th (for TC1), 12th (for TC2) and 13th September
2015 (for TC3). At each sampling zone, three 100 m horizontal transects were laid at high tidal level (H: 2.0 m
above C.D.), mid tidal level (M: 1.5 m above C.D.) and
low tidal level (L: 1.0 m above C.D.). Along every horizontal transect, ten random quadrats (0.5 m x 0.5m) were placed.
3.6.10
Inside a quadrat, any visible
epifauna were collected and were in-situ identified to
the lowest practical taxonomical resolution. Whenever possible a hand core sample (10 cm internal diameter ´ 20 cm depth) of sediments was collected in the quadrat. The core sample was gently washed through a sieve of mesh size 2.0 mm in-situ. Any
visible infauna were collected and identified. Finally the top 5 cm surface
sediments were dug for visible infauna
in the quadrat regardless of hand core sample was taken.
3.6.11
All collected fauna were
released after recording except some tiny individuals that are too small to be identified on site. These
tiny individuals were taken to laboratory for identification under dissecting microscope.
3.6.12
The taxonomic classification
was conducted in accordance to the following references: Polychaetes: Fauchald (1977), Yang and Sun (1988); Arthropods: Dai and Yang (1991), Dong (1991);
Mollusks: Chan and Caley (2003), Qi (2004).
Data
Analysis
3.6.13
Data collected from direct search and core
sampling was pooled in every quadrat for data analysis. Shannon-Weaver
Diversity Index (H¡¦) and Pielou¡¦s Species Evenness (J) were calculated for
every quadrat using the formulae below,
H¡¦= -£U ( Ni / N ) ln ( Ni / N ) (Shannon and Weaver,
1963)
J = H¡¦ / ln
S, (Pielou, 1966)
where S is the total number of species in the sample,
N is the total number of individuals, and Ni is the number of individuals of
the ith species.
Mudflat Ecology Monitoring Results and Conclusion
Horseshoe Crabs
3.6.14
In general, two species of
horseshoe crab Carcinoscorpius
rotundicauda (total 196 ind.) and Tachypleus
tridentatus (total 10 ind.) were recorded in the survey area. Individuals
were mainly found on fine sand while few were found on soft mud. The group size varied from 2 to 26 individuals for
every sight record. Although less number of Tachypleus tridentatus was recorded, the
average body size was larger than that of Carcinoscorpius
rotundicauda. Photo records were shown in Figure 3.1 of Appendix O
while the complete records of horseshoe crab survey in every sampling zone were
shown in Annex II of Appendix O.
3.6.15
One big individual of Carcinoscorpius rotundicauda was found trapped in a trash fish net (Figure 3.1 of Appendix O) on ST shore (GPS coordinate: 22¢X 17.385'
N, 113¢X 55.460' E). Its prosomal width reached 130.77 mm. After photo
recording, it was released to water. This big individual should have had
migrated to sub-tidal habitat. It might forage on intertidal habitat
occasionally during high tide period. Since intertidal soft shore was no longer
a nursery ground for this individual, its record was excluded from the data analysis. It was to avoid mixing up with juvenile population living on soft shore.
3.6.16
Table 3.1 of
Appendix O summarizes the survey
results of horseshoe crab in present survey. For Carcinoscorpius rotundicauda, it could be
found in all sampling zones while more individuals were recorded in TC3 and ST
(TC1: 41 ind., TC2: 4 ind., TC3: 70 ind., ST: 81 ind.). The search record was 10.3 ind. hr-1
person-1, 1.0 ind. hr-1 person-1, 11.7 ind. hr-1
person-1,
13.5 ind. hr-1 person-1 in TC1, TC2, TC3 and ST respectively. The size of
individuals was similar among TC1 (mean prosomal width:
39.58
mm), TC2 (36.20 mm) and ST
(37.03mm) while that of TC3 was smaller (27.27 mm).
3.6.17
For Tachypleus
tridentatus, it could be found in TC3 (1
ind.) and ST (9 ind.) only. The search records were 0.2 ind. hr-1
person-1 and 1.5 ind. hr-1 person-1 in TC3 and ST
respectively. The mean prosomal width of TC3 (53.90 mm) was larger than that of ST (48.50mm).
3.6.18
In the previous survey of March 2015, there was one important finding
that a mating pair of Carcinoscorpius rotundicauda was found in ST (prosomal width:
male 155.1 mm, female 138.2 mm) (Figure 3.2 of Appendix O). It indicated the importance of ST as a breeding
ground of horseshoe crab. Moreover, two moults of Carcinoscorpius rotundicauda were found in TC1 with similar prosomal width
130-140 mm (Figure 3.2 of Appendix O). It reflected that a certain numbers of moderately
sized individuals inhabited the sub-tidal habitat of Tung Chung Wan after its
nursery period on soft shore. These individuals might move onto soft shore
during high tide for feeding, moulting and breeding. Then it would return to
sub-tidal habitat during low tide. Because the mating pair should be inhabiting
sub-tidal habitat in most of the time. The record was excluded from the data
analysis to avoid mixing up with juvenile population living on soft shore.
3.6.19
No marked individual of horseshoe crab was
recorded in present survey. Some marked individuals were found in previous
surveys conducted in September 2013, March 2014 and September 2014. All of them
were released through a conservation programme conducted by Prof. Paul Shin
(Department of Biology and Chemistry, The City University of Hong Kong
(CityU)). It was a re-introduction trial of artificial bred horseshoe crab
juvenile at selected sites. So that the horseshoe crabs population might be
restored in the natural habitat. Through a personal conversation with Prof.
Shin, about 100 individuals were released in the sampling zone ST on 20 June
2013. All of them were marked with color tape and internal chip detected by
specific chip sensor. There should be second round of release between June and
September 2014 since new marked individuals were found in the survey of
September 2014.
3.6.20
The artificial bred individuals, if found,
would be excluded from the results of present monitoring programme in order to
reflect the changes of natural population. However, the mark on their prosoma
might have been detached during moulting after a certain period of release. The
artificially released individuals were no longer distinguishable from the
natural population without the specific chip sensor. The survey data collected
would possibly cover both natural population and artificially bred individuals.
Population
difference among the sampling zones
3.6.21
Figures 3.3 and 3.4 of Appendix O show the changes of number of individuals, mean prosomal width and search record of
horseshoe crabs Carcinoscorpius rotundicauda and Tachypleus tridentatus respectively in every sampling zone along the sampling months. In
general, higher search
records (i.e. number of individuals) of both species were always found in ST
followed by TC3 from September 2012 to September 2014. Then the search record
in TC3 was even higher than that in ST from March 2015 to June 2015. In this
sampling month (Sep. 2015), highest search record was found in ST again. For
TC1, the search record was at low to medium level and fluctuated slightly along
the sampling months. In contrast, much lower search record was found in
TC2 (2 ind. in September 2013, 1 ind. in March, June, September. 2014, March and
June 2015, 4 ind. in September. 2015). For spatial difference of horseshoe crab
size, larger individuals were usually found in ST while smaller individuals
were usually found in TC3.
3.6.22 Throughout the monitoring period
conducted, it was obvious
that TC3 and