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.7 (Mar 2014 to May 2014)
24 July 2014
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 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/C for HKLR and EP-353/2009/G for HKBCF were issued on 5 September
2013 and 6 August 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 Seventh 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 to 31 May 2014.
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 2014
|
April 2014
|
May 2014
|
Air
Quality
|
1-hr TSP
|
5, 11,
17, 21 and 27
|
2, 8, 14,
17, 23 and 29
|
5, 9, 15,
21, and 27
|
24-hr TSP
|
4, 10,
14, 20 and 26
|
AMS5: 1,
7, 11, 16, 22 and 28
AMS6: 1, 14, 15, 16, 22 and 28
|
2, 8, 14,
20, 26 and 30
|
Noise
|
5, 11, 17
and 27
|
2, 8, 14,
23 and 29
|
5, 15, 21
and 29
|
Water
Quality
|
3, 5, 7,
10, 12, 14, 17, 19, 21, 24, 26, 28 and 31
|
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
|
Chinese
White Dolphin
|
5, 11, 17
and 25
|
4, 14, 16
and 24
|
2, 19, 21
and 26
|
Mudflat
Monitoring (Ecology)
|
1, 2, 15,
16, 17 and 20
|
-
|
-
|
Mudflat
Monitoring (Sedimentation rate)
|
17
|
-
|
-
|
Site Inspection
|
5, 12, 19
and 28
|
2, 9, 16,
25 and 30
|
7, 14, 21
and 30
|
Due to the windy condition, the dolphins monitoring schedule was rescheduled
on 11, 17 and 25 March 2014.
The mudflat
monitoring was rescheduled from 19 March 2014 to 20 March 2014 as the weather
forecast indicated that the weather would be better on 20 March 2014 when
compared to those of 19 March 2014.
The motor of high
volume sampler (HVS) at AMS6 was malfunction on 7 April 2014. There was a
problem with power supply for the HVS at AMS6 on 11 April 2014. Therefore, the
dust monitoring on 7 and 11 April 2014 was rescheduled for 14 and 15 April
2014.
Due to boat availability issue, the dolphins monitoring schedule was
rescheduled from 15 April 2014 for 14 April 2014, from 17 April 2014 for 16 April
2014, from 22 April 2014 for
24 April 2014, from 7 May 2014 for 2
May 2014, and from 13 May 2014 for 21 May 2014.
The noise monitoring
on 27 May 2014 was rescheduled for 29 May 2014 due to the annual calibration.
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
|
1
|
0
|
Noise
|
Leq
(30 min)
|
0
|
0
|
Water
Quality
|
Suspended
solids level (SS)
|
13
|
2
|
Turbidity
level
|
0
|
0
|
Dissolved
oxygen level (DO)
|
0
|
0
|
Dolphin
Monitoring
|
Quarterly
Analysis (March to May 2014)
|
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
A summary of environmental complaints for this
reporting period is as follows:
Environmental Complaint No.
|
Date of Complaint Received
|
Description of Environmental Complaints
|
COM-2014-050
|
24 March
2014
|
Other: Dredged marine sediment
|
COM-2014-051
|
29 April
2014
|
Noise
|
COM-2014-052
|
2 May
2014
|
Noise
|
Notifications of Summons and Prosecutions
There were no notifications of summons or
prosecutions received during this reporting period.
Reporting Changes
This report has been developed in compliance
with the reporting requirements for the quarterly summary EM&A reports as
required by the Updated EM&A Manual for HKLR (Version 1.0).
The proposal for the change of Action Level and
Limit Level for suspended solid and turbidity was approved by EPD on 25 March
2013.
The revised Event and Action Plan for dolphin
Monitoring was approved by EPD on 6 May 2013.
The original monitoring station at IS(Mf)9
(Coordinate- East:813273, North 818850) was observed inside the perimeter silt
curtain of Contract HY/2010/02 on 1 July 2013, as such the original impact
water quality monitoring location at IS(Mf)9 was temporarily shifted outside
the silt curtain. As advised by the
Contractor of HY/2010/02 in August 2013, the perimeter silt curtain was shifted
to facilitate safe anchorage zone of construction barges/vessels until end of
2013 subject to construction progress.
Therefore, water quality monitoring station IS(Mf)9 was shifted to
813226E and 818708N since 1 July 2013.
According to the water quality monitoring team¡¦s observation on 24 March
2014, the original monitoring location of IS(Mf)9 was no longer enclosed by the
perimeter silt curtain of Contract HY/2010/02. Thus, the impact water quality monitoring
works at the original monitoring location of IS(Mf)9 has been resumed since 24
March 2014.
.
1.1.2 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/C for HKLR and EP-353/2009/G for HKBCF were issued on 5 September
2013 and 6 August 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.
1.1.5
This is the Seventh 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 to 31 May 2014.
1.2.1 The project organization structure and lines of
communication with respect to the on-site environmental management structure
with the key personnel contact names and numbers are shown in Appendix A.
1.3
Construction
Programme
1.3.1
A copy of the Contractor¡¦s construction programme
is provided in Appendix B.
1.4
Construction Works Undertaken During
the Reporting Period
1.4.1
A summary of the construction activities
undertaken during this reporting period is shown in Table
1.1. The Works areas of the Contract are
showed in Appendix C.
Table 1.1 Construction
Activities during Reporting Period
Site
Area
|
Description
of Activities
|
Portion X
|
¡P
Stone column
installation
¡P
Filling works
behind stone platform
¡P
Temporary stone
platform construction
¡P
Band drains
installation
¡P
Dismantling/trimming
of temporary 40mm stone platform for construction of seawall
¡P
Piling Works
|
Portion Y
|
¡P
Access shaft
construction for Scenic Hill Tunnel (SHT) & HKBCF to Airport Tunnel (HAT)
¡P
Utility culvert
excavation
¡P
Pipe piling works
for depressed roundabout
|
West Portal
|
¡P
Pipe roofing installation and excavation of SHT
|
Kwo Lo Wan /Airport Road
|
¡P
Works for
diversion of Airport Road and Kwo Lo Wan Road
|
Airport Express Line
|
¡P
Pre-grouting and
pipe piling works for Airport Express Line (AEL) access shafts
|
Kwo Lo Wan /Airport Road /Airport Express Line
|
¡P
Utilities
detection
¡P
Establishment of
site access
¡P
Works for east
access shaft
|
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 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.
2.3.1 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
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 inside the silt curtain were observed. The relevant records were kept
properly.
3.2.1
The monitoring results for 1-hour TSP and
24-hour TSP are summarized in Tables 3.1 and 3.2
respectively. Detailed impact air quality monitoring results and relevant graphical
plots are presented in Appendix G.
Table 3.1 Summary
of 1-hour TSP Monitoring Results During the Reporting Period
Reporting
Period
|
Monitoring
Station
|
Average (mg/m3)
|
Range (mg/m3)
|
Action Level (mg/m3)
|
Limit Level (mg/m3)
|
March 2014
|
AMS5
|
101
|
19 ¡V 275
|
352
|
500
|
AMS6
|
68
|
21 ¡V 144
|
360
|
April 2014
|
AMS5
|
65
|
10 ¡V 203
|
352
|
AMS6
|
46
|
16 ¡V 118
|
360
|
May 2014
|
AMS5
|
19
|
9 ¡V 36
|
352
|
AMS6
|
21
|
15 ¡V 32
|
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 2014
|
AMS5
|
97
|
47 ¡V 136
|
164
|
260
|
AMS6
|
121
|
74 ¡V 190
|
173
|
April 2014
|
AMS5
|
63
|
51 ¡V 86
|
164
|
AMS6
|
86
|
56 ¡V 158
|
173
|
May 2014
|
AMS5
|
26
|
19 ¡V 35
|
164
|
AMS6
|
46
|
28 ¡V 86
|
173
|
3.2.2
For 1-hr TSP, no Action and Limit Level exceedances were reocorded for
air during daytime on normal weekdays of the reporting period.
3.2.3
For 24-hr TSP, one Action level exceedance was recorded at station
AMS6 on 20 March 2014.
3.2.4
The general weather conditions at Tung Chung were
foggy and haze during the dust sampling period on 20 March 2014. The Air Quality Health Index (AQHI) recorded by EPD at the Tung Chung
station during the sampling time ranged from 3 (low) to 8 (very high). Therefore, it was considered that the exceedance was not related to the construction activities
of the Contract and was caused
by poor weather.
3.3
Noise Monitoring Results
3.3.1
The monitoring results for construction noise
are summarized in Table 3.3 and the
monitoring results and relevant graphical plots for this reporting
period are provided in Appendix H.
Table 3.3 Summary
of Construction Noise Monitoring Results During the Reporting Period
Reporting period
|
Monitoring
Station
|
Average Leq (30 mins), dB(A)*
|
Range of Leq
(30 mins), dB(A)*
|
Action Level
|
Limit Level Leq
(30 mins), dB(A)
|
March 2014
|
NMS5
|
60
|
59 ¡V 60
|
When one documented complaint is received
|
75
|
April 2014
|
60
|
58 ¡V 62
|
May 2014
|
59
|
56 ¡V 61
|
3.3.2
There were no Action and Limit Level exceedances for noise during
daytime on normal weekdays of the
reporting period.
3.3.3
Major noise sources during the noise monitoring
included construction activities of the Contract and nearby traffic noise.
3.4.1
Impact water quality monitoring was conducted at
all designated monitoring stations during the reporting period. Impact water quality monitoring results and
relevant graphical plots are provided in
Appendix I.
3.4.2
During the reporting period, there were thirteen
Action Level exceedances and two
Limit Level
exceedances of suspended solids level.
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 entire
quarterly period (March ¡V May 2014).
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 March to
May 2014, 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
891.87 km of survey effort was collected with 87.4% 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, 350.40 km and 541.47 km of survey effort were
conducted in NEL and NWL survey areas respectively.
3.5.11
The
total survey effort conducted on primary lines was 642.67 km, while the effort on secondary lines was 249.20 km. Both survey effort conducted on primary and secondary lines were
considered as on-effort survey data.
Summary table of the survey effort is shown in Annex I of Appendix J.
3.5.12
During the six sets of monitoring surveys in March to May 2014, a total of 31 groups of 103
Chinese White Dolphins were sighted. All except one
sighting were made during on-effort search. Twenty-five on-effort sightings were made on primary
lines, while another
five on-effort
sightings were made on secondary lines.
In this
quarterly period, all dolphin groups were sighted in NWL, while none was sighted in NEL Summary
table of the dolphin sightings is shown in Annex II of Appendix J.
Distribution
3.5.13
Distribution of dolphin sightings made during monitoring surveys in March, April and May 2014 was shown in Figure 1 of Appendix J
. Consistent with the dolphin distribution
patterns in the previous quarterly periods, the majority of dolphin sightings
were made in the northwestern portion of the North Lantau
region. Dolphin sightings were
particularly concentrated to the northern and northwestern sides of Lung Kwu
Chau, and at the mouth of Deep
Bay near Black Point
(Figure 1). Other dolphin sightings
were scattered between Lung Kwu Chau and Sha Chau, near Pillar Point, Tap Shek
Kok and the airport platform. No
dolphin was sighted in NEL survey area during the present quarterly period (Figure 1 of Appendix J).
3.5.14
None of the dolphin groups were sighted in the
vicinity of the HKLR03/ HKBCF reclamation sites or along the entire alignment
of Tuen Mun-Chek Lap Kok Link (TMCLKL) (Figure 1 of Appendix J).
3.5.15
Sighting distribution of the present impact
phase monitoring period (March to May 2014) was compared to the one during the
baseline monitoring period (September to November 2011). During the present quarter, dolphin
disappeared from the NEL region, which was in stark contrast to their frequent
occurrence around the Brothers Islands and in the vicinity of HKBCF reclamation
site during the baseline period (Figure
1 of Appendix J).
3.5.16
Dolphin occurrence in the northwestern portion
of North Lantau region was largely similar between the baseline and impact
phase quarters. However, during the
present impact monitoring period, there appeared to be much fewer dolphins
occurred in the middle portion of North Lantau region, where dolphins
supposedly moved between their core areas around Lung Kwu Chau and the Brothers
Islands (Figure 1 of Appendix J). Moreover, a
number of dolphin sightings were made to the west of Chek Lap Kok airport
(especially near the HKLR09 alignment) during the baseline period, but only one
sighting was made there during the present impact phase period.
3.5.17
As the baseline monitoring period was in
autumn season while the present monitoring period was in spring season, a
direct comparison in dolphin distribution between the two quarterly periods of
spring months in 2013 and 2014 was also made to avoid the potential bias in
seasonal variation (Figure 2 of Appendix J).
Between the two spring periods, none of the dolphin sightings was made
in NEL in spring 2014, while there were two sightings made in spring 2013. Moreover, more dolphin sightings were
made in the middle portion of North Lantau
waters and to the west of the airport platform (especially near the HKLR09
alignment) in spring 2013 than in spring 2014.
Encounter
Rate
3.5.18
For the three-month study
period in March, April and May 2014, 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 (Mar ¡V May 2014)
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 (5 & 11 Mar
2014)
|
0.00
|
0.00
|
Set 2 (17 & 25 Mar
2014)
|
0.00
|
0.00
|
Set 3 (4 & 14 Apr 2014)
|
0.00
|
0.00
|
Set 4 (16 & 24 Apr 2014)
|
0.00
|
0.00
|
Set 5 (2 & 19 May 2014)
|
0.00
|
0.00
|
Set 6 (21 & 26 May 2014)
|
0.00
|
0.00
|
Northwest Lantau
|
Set 1 (5 & 11 Mar
2014)
|
6.43
|
23.57
|
Set 2 (17 & 25 Mar
2014)
|
13.15
|
24.83
|
Set 3 (4 & 14 Apr 2014)
|
4.89
|
26.88
|
Set 4 (16 & 24 Apr 2014)
|
4.94
|
11.54
|
Set 5 (2 & 19 May 2014)
|
5.47
|
18.24
|
Set 6 (21 & 26 May 2014)
|
4.18
|
9.75
|
Table 3.5 Comparison
of Average Dolphin Encounter Rates between Reporting Period (Mar ¡VMay 2014) and
Baseline Monitoring Period (Sep ¡V Nov 2011)
Survey Area
|
Encounter
rate (STG)
(no. of on-effort dolphin sightings per 100 km of survey effort)
|
Encounter
rate (ANI)
(no. of dolphins from all on-effort sightings per 100 km of survey effort)
|
Reporting Period
|
Baseline
Monitoring Period
|
Reporting Period
|
Baseline
Monitoring Period
|
Northeast Lantau
|
0.00
|
6.00 ¡Ó 5.05
|
0.00
|
22.19 ¡Ó 26.81
|
Northwest Lantau
|
6.51 ¡Ó 3.34
|
9.85 ¡Ó 5.85
|
19.14 ¡Ó 7.19
|
44.66 ¡Ó 29.85
|
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)
3.5.19
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 6.00 sightings and 17.34
dolphins per 100 km of survey effort respectively, while the encounter rates of
sightings (STG) and dolphins (ANI) in NEL were both zero as no sighting was
made in this area.
3.5.20
In NEL, the average dolphin encounter rates (both STG and ANI) in the
present three-month impact phase were zero, which was the lowest since the
HKLR03 dolphin monitoring commenced in October 2012. Notably, dolphin encounter rates in
spring 2013 were also exceptionally low (Table 4), but dolphin occurrence have
even worsened in spring 2014.
3.5.21
It is a serious concern that dolphin occurrence in NEL in the past five
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). In fact, the present
quarter was the sixth consecutive quarters being accessed that have triggered
the Action Level under the Event and Action Plan. As discussed recently in Hung (2014),
the dramatic decline in dolphin usage of NEL waters in 2012 and 2013 (including
decline in abundance, encounter rate and habitat use, as well as shifts of individual
core areas and ranges away from NEL waters) was possibly related to the HZMB
construction works that were commenced in 2012.
3.5.22
On the other hand, the average dolphin encounter rates (STG and ANI) in
NWL during the present impact phase monitoring period were much lower
(reductions of 34% and 57% respectively) than the ones recorded in the 3-month
baseline period, indicating a reduced dolphin usage of this survey area during
the present construction period. In
fact, both encounter rates in spring 2014 were lower than ones in the previous
five quarterly periods. (Table 3.7).
Table 3.6 Comparison of Average Dolphin Encounter Rates in Northeast Lantau
Survey Area from All Quarters of Impact Monitoring Period and Baseline
Monitoring Period (Sep ¡V Nov 2011)
|
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
|
Note:
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.
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)
|
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
|
Note:
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.
3.5.23
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).
3.5.24
For the comparison between the baseline period and the present quarter
(sixth quarter of the impact phase being assessed), the p-value for the
differences in average dolphin encounter rates of STG and ANI were 0.0337 and
0.0535 respectively. If the alpha
value is set at 0.1, significant difference was detected between the baseline
and present quarters in both dolphin encounter rates of STG and ANI.
3.5.25
For the comparison between the baseline period and the cumulative quarters
in impact phase (i.e. first six quarters of the impact phase being assessed),
the p-value for the differences in average dolphin encounter rates of STG and
ANI were 0.0080 and 0.0032 respectively.
Even if the alpha value is set at 0.01, significant differences were
detected in both the average dolphin encounter rates of STG and ANI (i.e.
between the two periods and the locations)
3.5.26
As indicated in both dolphin distribution
patterns and encounter rates, dolphin usage has been significantly reduced in NEL
waters (especially around the Brothers Islands
and Shum Shui Kok) in the present quarterly period, and such low occurrence has
been consistently documented in previous quarters. This raises serious concern,
as the decline in dolphin usage could possibly link to the HZMB-related
construction activities in NEL waters, which include the 150 hectares of
habitat loss due to HKBCF reclamation, 23 hectares of habitat loss due to
HKLR03 reclamation, as well as the recently commenced TMCLKL construction that
involves intensive bored piling activities for the southern viaduct and further
reclamation of 16.5 hectares for the northern landfall.
3.5.27
To ensure the continuous usage of NEL waters
by the dolphins, every possible measure should be implemented by the contractors
and relevant authorities to minimize all disturbances to the dolphins, as a
future marine park around the Brothers Islands will be established in this
important dolphin habitat as a compensation measure for the habitat loss
resulted from the HKBCF reclamation works Unless such declining trend can be
reverted after the establishment of the Brothers Islands Marine Park, there
should be a presumption against further reclamation in North Lantau waters as
suggested in Hung
(2013, 2014).
Group
Size
3.5.28
Group size of Chinese White Dolphins ranged from 1-13 individuals per
group in North Lantau region during March ¡V May 2014. 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 (Mar ¡V May 2014) and Baseline Monitoring
Period (Sep¡V Nov 2011)
|
Average Dolphin Group Size
|
Reporting Period
|
Baseline Monitoring Period
|
Overall
|
3.32 ¡Ó 2.87 (n = 31)
|
3.72 ¡Ó 3.13 (n = 66)
|
Northeast Lantau
|
0.0
|
3.18 ¡Ó 2.16 (n = 17)
|
Northwest Lantau
|
3.32 ¡Ó 2.87 (n = 31)
|
3.92 ¡Ó 3.40 (n = 49)
|
3.5.29
The average dolphin group sizes in the entire North Lantau region as
well as in NWL waters during March ¡V May 2014 were lower than the ones recorded
during the three-month baseline period. (Table 3.8). In fact, 21 of the 31 groups were composed of 1-3 individuals only,
while only one group of dolphins was composed of more than 10 individuals.
3.5.30
Distribution of dolphins with larger group sizes (five individuals or
more per group) during the present quarter is shown in Figure 3
of Appendix J, with
comparison to the one in baseline period. In spring
2014, all larger dolphin groups were clustered to the south and north of Lung
Kwu Chau (Figure 3
of Appendix J). This distribution pattern was
quite different from the baseline period, when the larger dolphin groups were
distributed more evenly in NWL waters and a few more in NEL waters with no
particular concentration (Figure 3
of Appendix J). Notably none of the larger
dolphin groups were sighted near the HKLR03 reclamation site in the present
monitoring period. (Figure 3
of Appendix J).
Habitat
Use
3.5.31
From March to May 2014, the most heavily
utilized habitats by Chinese White Dolphins mainly concentrated to the north and northeast of Lung Kwu Chau. (Figures 4a and 4b
of Appendix J). None of the grids in NEL recorded the presence
of dolphins. Moreover, all grids
near HKLR03/HKBCF reclamation sites, HKLR09 or TMCLKL alignment did not record
any presence of dolphins during on-effort search in the present quarterly
period.
3.5.32
However, 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 will be presented when
more survey effort for each grid will be collected throughout the impact phase
monitoring programme.
3.5.33
When compared with the habitat use patterns
during the baseline period, dolphin usage in NEL was dramatically different
from the present impact monitoring period (Figure 5
of Appendix J). During the baseline period, nine grids between
Siu Mo To and Shum Shui Kok recorded moderately high to high dolphin densities,
which was in contrast to the complete absence of dolphins during the present
impact phase period (Figure 5
of Appendix J). On the other hand, the density patterns between the baseline and
impact phase monitoring periods were also different in NWL, with higher dolphin
usage near Sha Chau, between Pillar Point and airport platform, and along the
west boundary of Hong Kong territorial waters during the baseline period (Figure 5
of Appendix J).
3.5.34
The absence of dolphins in the identified
important habitats around the Brothers Islands and Shum Shui Kok in consecutive
quarters in 2013-14 is of serious concern. The future Brothers Islands Marine Park will be
established in this area upon the completion of HKBCF reclamation works, as an
important compensation measure for the associated habitat loss. As suggested recently in Hung (2014),
such low usage of dolphins in this important habitat in the past two years was
possibly related to the on-going HZMB-related construction works. Continuous monitoring of such diminished
use should be continued in this important dolphin habitat in the upcoming quarters.
Mother-calf Pairs
3.5.35
During the three-month
study period, a
total of five unspotted juveniles (UJ) were sighted in
NWL survey areas. These young calves comprised of 4.9% of all animals sighted, which was lower than the percentage recorded during the baseline
monitoring period (6.8%).
3.5.36
These young calves were only present near Lung
Kwu Chau or at the mouth of Deep Bay (Figure 6 of Appendix J), which was very different from their
distribution pattern during the baseline period when young calves were sighted
throughout the NWL survey area as well as a few sighted in NEL waters. None of these young calves were sighted
in the vicinity of the HKBCF/HKLR03 reclamation sites and HKLR09/TMCLKL
alignments during the present quarter (Figure 6 of Appendix J).
Activities
and Associations with Fishing Boats
3.5.37
A total of five dolphin sightings were associated with feeding and socializing activities
during the three-month study period. The percentage of feeding
activities comprised of 9.7%
of the total number of dolphin sightings, which was slightly lower than the one
recorded during the baseline period (11.6%). On the contrary, the percentage of
socializing activities during the present impact phase monitoring period (6.5%)
was slightly higher than the one recorded during the baseline period (5.4%).
None of the dolphin groups was engaged in traveling or milling/resting activity during the present impact monitoring periods.
3.5.38
Distribution of dolphins engaged in feeding and socializing activities during the present three-month period is shown in Figure 7
of Appendix J. The sightings associated with these activities were only found near Lung
Kwu Chau but not elsewhere in North Lantau waters, which was drastically
different from the distribution pattern of these activities during the baseline
period (Figure 7
of Appendix J).
3.5.39
During the three-month period, none of the 31 dolphin groups was
found to be associated with an operating fishing vessels in North Lantau waters.
The rare
events of fishing
boat association in
the present and previous quarters were consistently
found, and were likely
related to the recent trawl ban being implemented in December 2012 in Hong Kong waters.
Photo-identification
and Individual Range Use
3.5.40
From
March to May 2014, over 3,000 digital photographs of Chinese White Dolphins were taken
during the impact phase monitoring surveys for the photo-identification work.
3.5.41
In
total, 45 individuals sighted 74 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.
3.5.42
Most
identified individuals were sighted only once or twice
during the three-month period, with the exception of six individuals being
sighted thrice, and another two individuals (NL48 and NL261) being sighted four
to five times on different survey days
during the three-month period.
3.5.43
Notably
six of these 45 individuals (i.e. NL33, NL182, NL295,
WL04, WL05 and WL199) were also sighted in West Lantau
waters during the HKLR09 monitoring surveys during the same three-month period,
showing their extensive movement between North and West Lantau regions.
3.5.44
Six
well-recognized females (NL33, NL46, NL104, NL145, NL202 and NL233) were
accompanied with their calves during their re-sightings. All of these mothers
were frequently sighted with their calves throughout the HKLR03 impact phase
monitoring period since October 2012.
3.5.45
Ranging patterns of the 45 individuals identified during the three-month
study period were determined by fixed kernel method, and are shown in Annex V of Appendix J.
3.5.46
All individuals sighted in this quarter were utilizing their range use
in NWL (especially around Lung Kwu Chau) but have avoided NEL, where some of
these individuals 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
during the baseline period.
3.5.47 For many individuals that have
previously utilized the Brothers Islands as their major core area of activities, they have apparently shifted their range use away from
this important habitat (e.g. EL01, NL24, NL33, NL120, NL191, NL260; Annex V of Appendix J). Such shifts of range use
and core area use were also well documented by Hung (2014).
3.5.48
The diminished or abandoned usage of NEL waters by a large number of
individual dolphins coincided well with the noticeable decline in dolphin
occurrence in NEL as discussed in Sections 3.5.13 to 3.5.27. This is of serious
concern, as the Brothers Islands in NEL was once identified an important
habitat for many year-round residents that focused their core area use there
(Hung 2008, 2013). Therefore, the
ranging pattern of individual dolphins should be continuously monitored around
Lantau waters, and measures should be taken to ensure that dolphins will
continue to move between NWL and NEL without any hindrance as a result of the
HZMB-related construction works
Action
Level / Limit Level Exceedance
3.5.49
There
was two Action Level exceedance of dolphin monitoring for the quarterly
monitoring data (March ¡V May 2014). According to the contractor¡¦s information, the marine activities undertaken for HKLR03
during the two quarterly periods (December 2013 to February 2014 and March 2014
to May 2014) included stone platform construction, reclamation, stone column
installation and excavation of stone platform, surcharge activities,
construction of seawall and geotextile tube installation works. There is no
evidence showing the current AL non-compliance directly related to the
construction works of HKLR03, although the generally increased amount of vessel
traffic in NEL during the impact phase has been partly contributed by HKLR03
works since 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.
3.5.50
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)).
3.5.51
For the comparison
between the baseline period and the present quarter (sixth quarter of the impact phase being assessed),), the p-value for
the differences in average dolphin encounter rates of STG and ANI were 0.0337
and 0.0535 respectively. If the
alpha value is set at 0.1, significant difference was detected between the
baseline and present quarters in both encounter rates of STG and ANI.
3.5.52
For
the comparison between the baseline period and the cumulative quarters in
impact phase (i.e. sixth quarter of the impact phase
being assessed), the p-value for the differences in average dolphin
encounter rates of STG and ANI were 0.0080 and 0.0032 respectively. Even if
the alpha value is set at 0.01, significant difference was detected in both the
average dolphin encounter rates of STG and ANI (i.e. between the two periods
and the locations).
3.5.53
The
AFCD monitoring data during March to May 2014 has been reviewed by the
dolphin specialist, and only one group of three dolphins was sighted from 88.43
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
2014 in NEL is accurate.
3.5.54
There
is no evidence showing that the sources of impact directly related to the
construction works of HKLR03 that may have affected the dolphin usage in the
NEL region.
3.5.55
All
dolphin protective measures are fully and properly implemented in
accordance with the EM&A Manual. The Contractor will continue to 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 practicable.
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 17 March 2014. The mudflat surface levels at the four
established monitoring stations and the corresponding XYZ HK1980 GRID
coordinates are presented in Table 3.8 and Table 3.9.
Table 3.8 Measured
Mudflat Surface Level Results
|
Baseline Monitoring
(September 2012)
|
Impact Monitoring
(March 2014)
|
Monitoring Station
|
Easting (m)
|
Northing (m)
|
Surface Level
|
Easting (m)
|
Northing (m)
|
Surface Level
|
(mPD)
|
(mPD)
|
S1
|
810291.160
|
816678.727
|
0.950
|
810291.185
|
816678.731
|
0.997
|
S2
|
810958.272
|
815831.531
|
0.864
|
810958.291
|
815831.495
|
0.920
|
S3
|
810716.585
|
815953.308
|
1.341
|
810716.576
|
815953.305
|
1.405
|
S4
|
811221.433
|
816151.381
|
0.931
|
811221.438
|
816151.359
|
0.984
|
Table 3.9 Comparison
of measurement
|
Comparison of measurement
|
Remarks and Recommendation
|
Monitoring Station
|
Easting (m)
|
Northing (m)
|
Surface Level
(mPD)
|
S1
|
0.025
|
0.004
|
0.047
|
Within tolerance, no
significant change
|
S2
|
0.019
|
-0.037
|
0.056
|
Within tolerance, no
significant change
|
S3
|
-0.009
|
-0.003
|
0.064
|
Level increased
|
S4
|
0.005
|
-0.022
|
0.053
|
Within tolerance, no
significant change
|
3.6.2
This measurement result was generally and relatively higher than the
baseline measurement at S3. The mudflat level is continuously increased. For
S1, S2 and S4 showed that 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 2014.
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 3.10 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)
|
03-Mar-14
|
7.76
|
13.8
|
7.4
|
7.81
|
8.30
|
4.15
|
05-Mar-14
|
7.48
|
7.85
|
9.5
|
7.38
|
7.15
|
8.30
|
07-Mar-14
|
7.03
|
1.55
|
7.4
|
7.19
|
3.85
|
8.90
|
10-Mar-14
|
7.45
|
8.10
|
13.9
|
7.20
|
4.15
|
4.20
|
12-Mar-14
|
7.53
|
7.75
|
9.3
|
7.25
|
6.95
|
7.35
|
14-Mar-14
|
7.32
|
15.6
|
12.95
|
7.57
|
10.35
|
12.10
|
17-Mar-14
|
7.34
|
18.75
|
29.2
|
7.34
|
8.05
|
11.9
|
19-Mar-14
|
7.11
|
22.05
|
36.7
|
7.15
|
10.10
|
11.25
|
21-Mar-14
|
6.64
|
18.55
|
15.65
|
7.17
|
11.70
|
17.7
|
24-Mar-14
|
6.91
|
1.55
|
8.85
|
7.26
|
3.80
|
9.45
|
26-Mar-14
|
7.50
|
5.65
|
7.80
|
7.56
|
5.90
|
6.20
|
28-Mar-14
|
7.94
|
8.60
|
11.35
|
8.90
|
6.85
|
11.65
|
31-Mar-14
|
7.35
|
9.45
|
16.9
|
7.13
|
8.50
|
15.60
|
Average
|
7.33
|
10.71
|
14.38
|
7.45
|
7.36
|
9.90
|
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 present survey was conducted on 1, 2, 15, 16, 17 and 20
March 2014. The locations of
sampling zones are shown in Annex I of
Appendix O.
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 17th (for zones
TC1 and TC2) and 20th (for zones TC3 and ST) March 2014. The weather
was cloudy and sunny on 17th and 20th March 2014
respectively.
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 17th (for zones
TC1 and TC2) and 20th (for zones TC3 and ST) March 2014. The weather
was cloudy and sunny on 17th and 20th March 2014
respectively.
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 ¡V 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 1st (for ST),
2nd (for TC3), 15th (for TC1) and 16th March
2014 (for TC2).
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¡¦= -£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
3.6.12
Table 3.1 and Figure 3.1 of Appendix O shows the records of horseshoe crab survey at every sampling zone.
In general, Tachypleus tridentatus was
found at sampling zone ST (45 ind.) while Carcinoscorpius rotundicauda was found at all sampling zones
(TC1: 1 ind., TC2: 1 ind., TC3: 3 ind., ST: 16 ind.). All individuals were found on either fine sand
or soft mud substratum. Grouping
was observed while the group
size ranged 2-8 individuals.
3.6.13
Table 3.2 of
Appendix O summarizes the survey
results of horseshoe crab at every sampling zone. For Tachypleus tridentatus, the search record was
7.50 ind. hr-1 person-1 (mean prosomal width: 48.42 mm) at ST. According to Li (2008), the prosomal width of Tachypleus
tridentatus recorded ranged
32.31¡Ð70.59 mm that corresponded to
an estimated
age of
4.0¡V8.3 years old. For Carcinoscorpius rotundicauda, the search records were 0.25 ind. hr-1 person-1 (1 ind., prosomal width: 45.36 mm), 0.25 ind. hr-1 person-1 (1 ind., prosomal width: 44.61 mm), 0.75 ind. hr-1 person-1 (mean prosomal width: 49.81 mm), 2.67 ind. hr-1 person-1 (mean prosomal width: 39.28 mm) at TC1, TC2, TC3 and ST
respectively. The estimated age ranged 4.5-9.5 years old.
3.6.14
Besides, 18 and 3 labeled individuals of Tachypleus tridentatus were recorded in the
survey of Sep. 2013 and Mar. 2014 respectively. 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 and marked 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 to ST on 20 June 2013. All these labeled individuals
were not included in the results of present monitoring programme.
3.6.15
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 every sampling zone along the
sampling months. Among all
the sampling months, high search record was found at ST. In contrast, much lower search record was found at other sampling zones
especially at TC2 (2 ind. in Sep. 2013 and 1 ind. in Mar. 2014 only).
3.6.16 Based on the populations of both horseshoe crab species among the four
sampling zones, it was obvious that ST was an
important nursery ground for horseshoe crab especially newly hatched
individuals due to larger area of suitable substratum (fine sand or soft mud)
and less human disturbance (far from urban district). Relatively, other
sampling zones were not suitable for nursery of horseshoe crab especially TC2.
Possible factors were less area of suitable substratum (especially TC1) and
higher human disturbance (TC1, TC2 and TC3: close to urban district and easily
accessible by people). For TC2, large daily salinity fluctuation was a possible
factor either since it was flushed by two rivers under tidal inundation. The
individuals found in TC1, TC2 and TC3 were believed foraging from the ST during
high tide while it might return to ST over a certain period. It accounted for
the variable search records at the three sampling zones along the sampling
months. Beside there was no spatial difference of horseshoe crab size (prosomal
width) among the sampling zones.
3.6.17 During the survey period from
Sep. 2012 to Mar. 2014, the search record of horseshoe crab declined obviously
during dry season (Dec.) (Figures 3.2 and 3.3 of Appendix O). And no
individual was found at all sampling zones in Dec. 2012.
As mentioned, 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 ind. hr-1 person-1 and 0 ind. hr-1
person-1 in wet season and dry
season respectively (details see Li, 2008). After December, the search record increased
along with the warmer climate.
3.6.18
Relative to Tachypleus tridentatus, Carcinoscorpius rotundicauda was a less common species. During the survey period from Sep. 2012 to
Dec 2013, it was not found except that 4 individuals were found at ST in Dec.
2012. This species was believed present in ST at very low number while
encounter was rare. Until the present survey, it was recorded again at all
sampling zones especially ST. Based on its average size (mean prosomal width
39.28-49.81 mm), it indicated that breeding of Carcinoscorpius rotundicauda had occurred 3-4 years ago. However,
these individuals were still small while their walking trail was less
conspicuous. It leaded to low visual detection in previous sampling months.
3.6.19
For Tachypleus tridentatus, sharp increase of
number of individuals was recorded from Mar. 2013 (15 ind.), Jun. 2013 (59
ind.) to Sep. 2013 (94 ind.) at ST. According to a personal conversation with
Prof. Shin (CityU), his monitoring team had recorded similar increase of
horseshoe crab population during wet season this year. It was believed the
suitable ambient temperature increased its conspicuousness.
3.6.20
Figure 3.4 of Appendix O shows the changes of
prosomal width of horseshoe crab Tachypleus tridentatus and Carcinoscorpius rotundicauda at the important nursery ground ST. For Tachypleus tridentatus, it was believed that
most of individuals (50% records between upper and lower quartile), recorded in
the dry season, had grown to a size of double in Jun. 2013 (prosomal width
increase from 10-20 mm to 30-50 mm). The individuals remained similar in size
in Sep. 2013 followed by further size increase (32-71 mm) in Mar. 2014. It
indicated the moulting period occurring during March-June and December-March.
As mentioned, Carcinoscorpius rotundicauda was less
common in ST while it was found in two sampling months only. Hence the change
of size was yet to be determined.
3.6.21
The present survey was the sixth time of sampling of the EM&A
programme during the construction period. Based on the
results, impact 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 crab individuals
in warm weather, large number of dead
individuals on the shore) is observed, it would be
reported as soon as possible.
Seagrass
Beds
3.6.22 Table 3.3 and Figure 3.5 of Appendix O show the
records of seagrass beds survey at every sampling zone. Seagrass was recorded in ST only summarized in Table 3.4. The most
largest bed was composed
of one long strand and two medium patches of Halophila ovalis nearby the mangrove vegetation on sandy substratum at tidal level 2 m
above C.D.. The estimated total
area was about 713 m2 with vegetation
coverage 90-100%. In Dec. 2013, flowers were observed that
indicated the reproductive period of H. ovalis (Figure 3.6 of Appendix O).
3.6.23 Moreover, 24 small patches and 7 medium patches of H. ovalis
were recorded on soft mud at tidal level between 1.0 m and 1.5 m above C.D..
The estimated area of each patch varied highly and ranged 1-72 m2
with estimated coverage ranging 40-80%. The number of patches has been increasing since Sep. 2013. Seasonal
recruitment and spreading of H. ovalis were occurring along with colder
climate.
3.6.24 Four small patches of Zostera japonica were found within the long strand of Halophila ovalis. The
estimated total area was
3.3 m2 while
the estimated coverage was about 10-60%.
3.6.25 Figure 3.7 of Appendix O shows the changes of estimated total area of seagrass beds at ST along the sampling
months. For seagrass Halophila ovalis, the total area and estimated coverage increased
gradually. It showed that the seagrass was in scattered patches on the shore
during dry season of 2012. Then it grew larger or merged as larger patches
during 2013. However it was doubt that the newly recruited patches of seagrass
would survive the natural heat stress, predation and wave action in the next
wet season.
3.6.26 For seagrass Zostera
japonica, it was not reported in the surveys of Sep. and Dec. 2012. Seasonal
recruitment of few patches was reported between December and March. Then the
patch size increased and merged gradually with the warmer climate. However the
patch size decreased sharply since Sep. 2013 and remained similar. The patch might
not overcome the high heat stress exerted on shore between June and September
2013.
3.6.27 The present survey was the sixth
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 seagrass. The seagrass area of Halophila ovalis was increasing steadily due to natural growth and seasonal recruitment.
Although that of Zostera
japonica decreased in the Sep. 2013 survey, it would be the
cause of natural heat stress. In case, abnormal
phenomenon (e.g. rapid reduction of seagrass patch size) was observed, it would
be reported as soon as possible.
Intertidal
Soft Shore Communities
3.6.28
Table 3.5 and Figure 3.8 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 the horizontal transect.
3.6.29 The distribution of substratum types varied among tidal levels and sampling zones. At TC1, higher percentages of ¡¥Gravels and Boulders¡¦ (70%) were recorded at high and mid tidal levels followed by ¡¥Sands¡¦ (20-30%). Higher percentage of ¡¥Gravels and Boulders¡¦ (60%) were recorded at low tidal
level followed by ¡¥Sands¡¦ (20%) and ¡¥Soft mud¡¦ (20%). At TC2, high percentage of ¡¥Sands¡¦ (60%) was recorded while the rest was ¡¥Soft mud¡¦ (40%) at high tidal level.
¡¥Sands¡¦ was recorded only at mid tidal level. Higher percentage of ¡¥Soft mud¡¦
(70%) was recorded at low tidal level followed by ¡¥Sands¡¦. At TC3, ¡¥Sands¡¦ (100%) was recorded only
at high tidal level. High percentage of ¡¥Sands¡¦ (70%) was recorded at mid tidal level followed by ¡¥Soft mud¡¦ (30%). ¡¥Gravels and
Boulders¡¦ was recorded only (100%) at low tidal level. At ST, ¡¥Gravels and Boulders¡¦ (90-100%) was the major substratum at high and mid tidal levels. Even
distribution of ¡¥Soft mud¡¦ (50%), ¡¥Sands¡¦ (30%) and ¡¥Gravels and Boulders¡¦
(20%) were recorded at low tidal level.
3.6.30 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.
3.6.31 Table 3.6 of Appendix O lists the total abundance, density and number of taxon of every phylum in the present survey. A total of 14383 individuals were recorded. Mollusks
were significantly the most abundant phylum (total individuals 14165, density 472
ind. m-2, relative abundance 98.5%). The second abundant group was arthropod
(total individuals: 113, density 4 ind. m-2, 0.8%). Relatively
other phyla were very low in abundance (£0.4%).
Similarly, the most diverse phylum were mollusks (40 taxa) followed by arthropods (11 taxa) and annelids (10 taxa). The taxa of
other phyla were relatively less (1 taxon). The complete list of collected specimens
is provided in Annex III of Appendix O.
3.6.32
Table 3.7 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: 1732-4800
ind., relative abundance 95.4-99.0%).
Arthropods were the second abundant phylum (no. of individuals: 16-44 ind., 0.4-2.4%) 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%) except the annelids at TC2 (no. of individuals: 26 ind., relative
abundance 1.4%).
3.6.33
Table 3.8 of Appendix O lists the
abundant species (relative abundance >10%) at every sampling zone. At TC1, gastropod Batillaria multiformis was abundant at all tidal
levels especially high
tidal level (133-526 ind. m-2, relative abundance 26-80%). Rock
oyster Saccostrea cucullata was at moderate abundance at mid and low tidal levels (84-133 ind. m-2, 16-32%). Gastropod Monodonta
labio (43-74 ind. m-2, 10-14%) was the
third abundant at mid and low tidal levels.
3.6.34
At TC2, gastropods Batillaria multiformis (84 ind. m-2, relative
abundance 34%) and Cerithidea
djadjariensis (76 ind. m-2, 31%) were abundant at high tidal level. At mid tidal level, rock oyster Saccostrea cucullata was the most abundant (86 ind. m-2, 32%) followed by less abundant gastropods Cerithidea djadjariensis (45 ind. m-2, 17%) and Batillaria
zonalis (39 ind. m-2, 14%). At low tidal level, gastropod Batillaria zonalis (77 ind. m-2, 37%) was the most abundant species followed by
rock oyster Saccostrea cucullata (33 ind. m-2, 16%), Cerithidea djadjariensis (33 ind. m-2, 16%) and Batillaria multiformis (24 ind. m-2, 12%).
3.6.35 At TC3,
gastropod Batillaria multiformis was highly abundant at all tidal levels (214-444 ind.
m-2, relative
abundance 43-65%). Gastropod Cerithidea
djadjariensis (146 ind. m-2, 21%) and Monodonta labio (97 ind. m-2, 26%) were the second abundant at high and mid
tidal levels respectively. At low tidal level, other
abundant species were rock
oyster Saccostrea cucullata (186 ind. m-2,
21%) and gastropod Cerithidea
djadjariensis (162 ind. m-2, 18%).
3.6.36 At ST,
gastropod Batillaria multiformis
was highly abundant (585 ind. m-2,
relative abundance 73%) at high tidal level followed by gastropod Monodonta labio (81 ind. m-2, 10%). At
mid tidal level, rock oyster Saccostrea cucullata was the most abundant (162 ind. m-2, 31%) while other less abundant taxa were
gastropods Batillaria multiformis (131 ind. m-2, 25%) and Monodonta labio (62 ind. m-2, 12%). At low tidal level, rock oyster Saccostrea cucullata (49 ind. m-2, 32%),
gastropods Cerithidea djadjariensis (24 ind. m-2, 16%) and Batillaria
zonalis (23 ind. m-2, 15%) were abundant taxa with much lower
abundance relative to that at high and mid tidal levels.
3.6.37 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, gastropods Batillaria multiformis (7002 ind., 49%) and Cerithidea djadjariensis (1749 ind., 12%) were the most common
occurring species on sandy substratum mainly among the four sampling zones.
Moreover rock oyster
Saccostrea cucullata (2089 ind.,
15%) and gastropod Monodonta labio (1032 ind., 7%) were commonly occurring species inhabiting
gravel and boulders substratum.
3.6.38
Table 3.9 of Appendix O 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 generally
similar (6-14 spp. 0.25 m-2). The mean densities of TC3 (376-879 ind. m-2) was generally
higher than that of TC1 (417-656 ind. m-2) followed by ST (152-800
ind. m-2) and TC2 (211-270 ind. m-2). The mean
biodiversity index was similar and ranged 1.13-1.53. The species evenness at
TC2 (0.75) was generally higher than that at other sampling zones (0.53-0.61).
3.6.39 Across the tidal levels, there
was no difference of the mean number of species. Higher mean densities were
observed at high and mid tidal levels except the sampling zone TC3. Usually
higher mean biodiversity index and species evenness were observed at mid and
low tidal levels.
3.6.40 Figure 3.9 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 of any biological parameters was observed at all sampling zones.
Although declined densities were observed during dry season (December), 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 along with the hot, wet season.
3.6.41
The present survey was the sixth time of sampling of the EM&A
programme during the construction period. Based on the
results, impacts of the HKLR project were not 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
For air quality, there were no
Action and Limit Level exceedances for 1-hr TSP recorded during this reporting
period. For
24-hour TSP, one Action level exceedance was recorded at station
AMS6 on 20 March 2014.
Noise
4.1.3
No Action and Limit Level exceedances for noise were recorded during
this reporting period.
Water Quality
4.1.4 During the reporting period, there were thirteen Action Level exceedances and two Limit Level exceedances of suspended solids
level. No exceedances of turbidity
level and dissolved oxygen level were recorded. There were no specific activities recorded during the
monitoring period that would cause any significant impacts on monitoring
results and no leakage of turbid water or any abnormity or malpractice was
observed during the sampling exercise. Therefore, all exceedances were considered as
non-contract 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 were two Action Level
exceedances of dolphin monitoring for the quarterly monitoring data (March ¡V May 2014). According to the contractor¡¦s information, the marine activities undertaken for HKLR03
during the two quarterly periods (December 2013 to February 2014 and March 2014
to May 2014) included stone platform construction, reclamation, stone column
installation and excavation of stone platform, surcharge activities,
construction of seawall and geotextile tube installation works.
4.1.6
There is no evidence showing the current AL
non-compliance directly related to the construction works of HKLR03, although
the generally increased amount of vessel traffic in NEL during the impact phase
has been partly contributed by HKLR03 works since 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.
4.1.7 All dolphin protective measures
are fully and properly implemented in accordance with the EM&A Manual. The Contractor will continue to 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 practicable.
Table
4.1 Summary
of Water Quality Exceedances
Station
|
Exceedance Level
|
DO (S&M)
|
DO (Bottom)
|
Turbidity
|
SS
|
Total Number of Exceedances
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
IS5
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
17 Mar 2014
19 Mar 2014
2 Apr 2014
|
--
|
3
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS(Mf)6
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
19 Mar 2014
|
--
|
1
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS7
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
31
Mar 2014
|
0
|
1
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS8
|
Action Level
|
--
|
--
|
--
|
--
|
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
|
--
|
--
|
0
|
0
|
IS(Mf)9
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
26
Mar 2014
31 Mar 2014
|
0
|
2
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS10
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
31 Mar 2014
|
17 Mar 2014
19 Mar 2014
|
1
|
2
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR3
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
17 Mar 2014
|
--
|
1
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
19 Mar 2014
|
--
|
1
|
0
|
SR4
|
Action Level
|
--
|
--
|
--
|
--
|
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
14 May 2014
|
0
|
1
|
SR5
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
21 Mar 2014
|
19 Mar 2014
|
1
|
1
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR10A
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR10B
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Total
|
Action
|
0
|
0
|
0
|
0
|
0
|
0
|
7
|
6
|
13**
|
Limit
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
1
|
2**
|
Notes:
S: Surface;
M: Mid-depth;
* The total
exceedances.
4.2
Summary of Environmental Complaint, Notification of
Summons and Successful Prosecution
4.2.1
There were three environmental complaints received during this
reporting period. 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. The summary of environmental
complaints is presented in Table 4.2. The details of environmental
complaints are presented in Appendix N.
Table 4.2 Summary of Environmental
Complaints for the Reporting Period
Environmental Complaint No.
|
Date of Complaint Received
|
Description of Environmental Complaints
|
COM-2014-050
|
24 March 2014
|
Other: Dredged marine sediment
|
COM-2014-051
|
29 April 2014
|
Noise
|
COM-2014-052
|
2 May 2014
|
Noise
|
4.2.2
No notification of
summons and prosecution was received during the reporting period.
4.2.3
Statistics on
notifications of summons and successful prosecutions are summarized in Appendix M.
5
COMMENTS, RECOMMENDATIONS AND CONCLUSION
5.1.1 According to the environmental site inspections undertaken during
the reporting period, the following recommendations were provided:
¡± The
Contractor was reminded to clean up the excess fill materials on the passage
way of vessel Lun Li at S7 and vessel Shing Ming 83.
¡± The
Contractor was reminded to provide maintenance/place properly for the silt
curtains at Portion X.
¡± The
Contractor was reminded to provide the noise emission label for hand held
breaker at N4 and air compressor at N1 and S16.
¡± The
Contractor was reminded to clean up the stagnant water inside the drip tray at
S8/S9 and S15.
¡± The
Contractor was reminded to clean up the muddy water on the public road at
S8/S9, S15, S16 and S25.
¡± The
Contractor was reminded to provide clear labels for waste oil and chemical
containers at S8/S9.
¡± The
Contractor was reminded to clean up the oil film inside the washing wheel bay
at S8/S9.
¡± The
Contractor was reminded to provide cover or water spraying for the dry
stockpiles at S19.
¡± The
Contractor was reminded to provide the drip tray for the oil container at
S15/S11, N4 and at vessel of Hoi Pok 9.
¡± The
Contractor was reminded to provide the drip tray for the waste chemical
containers at N13.
¡± The
Contractor was reminded to clean up the oily film at S8 and S16.
¡± The
Contractor was reminded to clear up the leakage oil and remove the diesel tank
at S16.
¡± 8. The
Contractor was reminded to provide the water spray on the haul road at S19.
¡± The
Contractor was reminded to provide maintenance for the noise barrier at
S16/S11.
¡± The
Contractor was reminded to clean up the oil spillage at S8.
¡± The
Contractor was reminded to provide a drip tray for the oil drum at S16/S11.
¡± The
Contractor was reminded to clean up the oily water and store properly for
disposal at N1.
¡± The Contractor
was reminded to clean up the fill materials on passage way of vessel Shing Ming
98.
¡± The
Contractor was reminded to provide drip trays for the chemical containers at
FB101, N1, S8 and N4.
¡± The
Contractor was reminded to provide a stopper for the drain hole of the drip
tray at S22 and S25.
¡± The
Contractor was reminded to remove construction materials from the drip trays at
S22.
¡± The
Contractor was reminded to remove construction materials and rubbish bin from
the drip trays at S25.
¡± The
Contractor was reminded to clean up the stagnant water and fill up the recesses
for the lifting eyes of concrete blocks at S25.
¡± The
Contractor was reminded to clean up the fill materials on passage way of vessel
Kiu Tak.
¡± The
Contractor was reminded to provide a drip tray for the waste oil container at
N13.
¡± The
Contractor was reminded to provide a cover for the opened cement bags at S11.
¡± The
Contractor was reminded to remove the stagnant water inside the recesses for
lifting eyes of concrete blocks at N1.
¡± The
Contractor was reminded to close the gap for silt curtains at Portion X.
¡± The
Contractor was reminded to clean up the fill materials on passage way of vessel
Shing Ming 83.
¡± The
Contractor was reminded to provide a drip tray for waste oil and chemical
containers at S11/S16.
¡± The
Contractor was reminded to clean up the oily film at S11/S16 and S15.
¡± The
Contractor was reminded to clean up the stagnant water inside the tubes at N4A.
¡± The
¡± The
Contractor was reminded to provide a 3-side sheltered cover for the cement
mixing plant at S8.
¡± The
Contractor was reminded to provide a drip tray for the oil container at
S15/S11.
¡± The
Contractor was reminded to provide water spraying on the dry sand stockpile at
S16.
¡± The
Contractor was reminded to place the chemical inside a drip tray properly at
S16.
¡± The
Contractor was reminded to clean up the stagnant water inside the recesses for
lifting eyes of concrete blocks at N13.
¡± The
Contractor was reminded to provide a proper impervious cover for the cement
bags at S16/S11 and S23.
¡± The
Contractor was reminded to remove the stagnant water inside the bucket at S15.
¡± The
Contractor was reminded to provide a drip tray and clear label for the waste
oil container at Shing Ming 83.
¡± The Contractor
was reminded to close the gaps between the silt curtains at Portion X.
¡± The
Contractor was reminded to clean up the stagnant water at N4.
¡± The
Contractor was reminded to provide a properly cover for the sand stockpiles at
N24.
¡± The
Contractor was reminded to clean up the stagnant water which inside the drip
tray at S8-S9.
¡± The
Contractor was reminded to provide a 3-sided shelter for the cement storage
area at S8-S9.
¡± The
Contractor was reminded to remove the oily film inside the wastewater
collection pit at N1.
¡± The
Contractor was reminded to close the gap between the enclosed area and barge
parking place at S7.
¡± The
Contractor was reminded to cover the cement bags entirely by impervious
sheeting or placed them in an area sheltered on the top and 3 sides cement bags
at S19.
¡± The
Contractor was reminded to clean up the stagnant water inside recesses for
lifting eyes of the water crash barrier at WA06.
¡± The
Contractor was reminded to remove stagnant water at N13 and WP4.
¡± The
Contractor was reminded to cover bags of cement entirely with impervious sheets
to avoid dust emission at WP5.
5.2.1
The
impact monitoring programme for air quality, noise, water quality and dolphin
ensured that any deterioration in environmental condition was readily detected
and timely actions taken to rectify any non-compliance. Assessment and analysis
of monitoring results collected demonstrated the environmental impacts of the
contract. With implementation of the recommended environmental mitigation
measures, the contract¡¦s environmental impacts were considered environmentally
acceptable. The weekly environmental site inspections ensured that all the
environmental mitigation measures recommended were effectively implemented.
5.2.2
The
recommended environmental mitigation measures, as included in the EM&A
programme, effectively minimize the potential environmental impacts from the
contract. Also, the EM&A programme effectively monitored the environmental
impacts from the construction activities and ensure the proper implementation
of mitigation measures. No particular recommendation was advised for the
improvement of the programme.
5.3.1
The construction phase and
EM&A programme of the Contract commenced on 17 October 2012. This is the Seventh Quarterly EM&A Report which summarises
the monitoring results and audit findings of the EM&A programme during the
reporting period from 1 March to 31 May 2014.
Air Quality
5.3.2
For air quality, there were no
Action and Limit Level exceedances for 1-hr TSP recorded during this reporting
period.
5.3.3
For 24-hour TSP, one Action level
exceedance was recorded at station AMS6 on 20 March 2014.
Noise
5.3.4
For construction noise, there
were no Action Level and Limit Level exceedances during the reporting
period.
Water Quality
5.3.5
During the reporting period, there were thirteen
Action Level exceedances and two
Limit Level
exceedances of suspended solids level.
Dolphin
5.3.6
There was two Action Level exceedances of dolphin monitoring for the quarterly monitoring
data (March ¡V May 2014).
5.3.7
During this quarter of dolphin
monitoring, no adverse impact from the activities of this construction project
on Chinese White Dolphins was noticeable from general observations.
5.3.8
Although dolphins rarely
occurred in the area of HKLR03 construction in the past and during the baseline
monitoring period, it is apparent that dolphin usage has been significantly
reduced in NEL in 2012 and 2013, and many individuals have shifted away from
the important habitat around the Brothers Islands.
5.3.9
It critical to monitor the
dolphin usage in North Lantau region in the
upcoming quarters, to determine whether the dolphins are continuously affected
by the various construction activities in relation to the HZMB-related works,
and whether suitable mitigation measure can be applied to revert situation.
Mudflat
-Sedimentation Rate
5.3.10 This measurement result was
generally and relatively higher than the baseline measurement at S3. The
mudflat level is continuously increased. For S1, S2 and S4 showed that the
level has increased within tolerance and their sea bed depth would not be considered as significant change.
5.3.11
Impact water quality monitoring
in San Tau (monitoring station SR3) was conducted in March
2014. The monitoring parameters included dissolved
oxygen, turbidity and suspended solids.
Mudflat - Ecology
5.3.12
An active search method was
adopted for horseshoe crab survey at each sampling zone. In general, horseshoe crab Tachypleus tridentatus was found at sampling zone ST (45 ind.) while Carcinoscorpius rotundicauda was found at all sampling zones(TC1: 1 ind., TC2:
1 ind., TC3: 3 ind., ST: 16 ind.). All individuals were found on either fine sand or soft mud substratum. Grouping was observed while the group size ranged 2-8 individuals. Among all the sampling
months, high search record was found at ST. In contrast, much lower search record was found at other sampling zones
especially at TC2 (2 ind. in Sep. 2013 and 1 ind. in Mar. 2014 only). Based on the populations of both horseshoe crab species among the four
sampling zones, it was obvious that ST was an
important nursery ground for horseshoe crab especially newly hatched
individuals due to larger area of suitable substratum (fine sand or soft mud)
and less human disturbance (far from urban district). Relatively, other
sampling zones were not suitable for nursery of horseshoe crab especially TC2.
Possible factors were less area of suitable substratum (especially TC1) and
higher human disturbance (TC1, TC2 and TC3: close to urban district and easily
accessible by people).
5.3.13
In March 2014 survey, Carcinoscorpius
rotundicauda was recorded again at all sampling zones especially ST. Based
on its average size (mean prosomal width 39.28-49.81 mm), it indicated that
breeding of Carcinoscorpius rotundicauda
had occurred 3-4 years ago. However, these individuals were still small while
their walking trail was less conspicuous. It leaded to low visual detection in
previous sampling months.
As mentioned, Carcinoscorpius
rotundicauda was less common in ST while it was found in two sampling
months only. Hence the change of size was yet to be determined.
5.3.14 An active search method was adopted for seagrass bed survey at each
sampling zone. Seagrass was recorded in ST only.
The most largest bed was composed of one long strand and two medium patches of Halophila ovalis nearby the mangrove vegetation on sandy substratum at tidal level 2 m
above C.D.. The estimated total
area was about 713 m2 with vegetation
coverage 90-100%. Moreover, 24 small patches and 7 medium patches of H.
ovalis were recorded on soft mud at tidal level between 1.0 m and 1.5 m
above C.D.. The estimated area of each patch varied highly and ranged 1-72 m2
with estimated coverage ranging 40-80%. The number of patches has been increasing since Sep. 2013. Seasonal recruitment
and spreading of H. ovalis were occurring along with colder climate. Four small patches of Zostera
japonica were found within the long strand of Halophila
ovalis. The estimated total area was
3.3 m2 while
the estimated coverage was about 10-60%.
5.3.15
The intertidal soft shore
community surveys were conducted in low tide period at each sampling zone). A
total of 14383 individuals
were recorded. Mollusks were significantly the most abundant phylum (total
individuals 14165, density 472 ind. m-2, relative abundance
98.5%). The second
abundant group was arthropod (total individuals: 113, density 4
ind. m-2, 0.8%). Relatively other phyla were
very low in abundance (£0.4%).
Similarly, the most diverse phylum were mollusks (40 taxa) followed by arthropods (11 taxa) and annelids (10 taxa). The taxa of
other phyla were relatively less (1 taxon).
5.3.16 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, gastropods Batillaria multiformis (7002 ind., 49%) and Cerithidea djadjariensis (1749 ind., 12%) were the most common
occurring species on sandy substratum mainly among the four sampling zones.
Moreover rock oyster
Saccostrea cucullata (2089
ind., 15%) and gastropod Monodonta labio (1032 ind., 7%) were commonly occurring species inhabiting
gravel and boulders substratum.
5.3.17
The March 2014 survey was the sixth time of sampling of the EM&A programme during the construction
period. Based on the results, impacts of the HKLR
project were not detected on horseshoe crabs, seagrass
and intertidal soft shore community.
Environmental Site
inspection and Audit
5.3.18
Environmental site inspection
was carried out on 5, 12, 19 and 28 March 2014, 2, 9, 16,
25 and 30 April
2014 and 7, 14, 21 and 30 May 2014. Recommendations
on remedial actions were given to the Contractors for the deficiencies
identified during the site inspections.
5.3.19
There were three environmental complaints received during this reporting period.
5.3.20
No notification of summons and
prosecution was received during the reporting period.