The Hong Kong-Zhuhai-Macao Bridge (HZMB) Hong
Kong Link Road (HKLR) serves to connect the HZMB Main Bridge at the Hong Kong
Special Administrative Region (HKSAR) Boundary and the HZMB Hong Kong Boundary
Crossing Facilities (HKBCF) located at the north eastern waters of the Hong
Kong International Airport (HKIA).
The HKLR project has been separated into two
contracts.They are Contract No.
HY/2011/03 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between
Scenic Hill and Hong Kong Boundary Crossing Facilities (hereafter referred to
as the Contract) and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong
Kong Link Road-Section between HKSAR Boundary and Scenic Hill.
China State Construction Engineering (Hong Kong)
Ltd. was awarded by Highways Department as the Contractor to undertake the
construction works of Contract No. HY/2011/03. The main works of the Contract
include land tunnel at Scenic Hill, tunnel underneath Airport Road and Airport
Express Line, reclamation and tunnel to the east coast of the Airport Island,
at-grade road connecting to the HKBCF and highway works of the HKBCF within the
Airport Island and in the vicinity of the HKLR reclamation.The Contract is part of the HKLR Project
and HKBCF Project, these projects are considered to be “Designated Projects”,
under Schedule 2 of the Environmental Impact Assessment (EIA) Ordinance (Cap
499) and EIA Reports (Register No. AEIAR-144/2009 and AEIAR-145/2009) were
prepared for the Project.The
current Environmental Permit (EP) EP-352/2009/D for HKLR and EP-353/2009/K for
HKBCF were issued on 22 December 2014 and 11 April 2016, respectively. These
documents are available through the EIA Ordinance Register. The construction
phaseof 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 fourteenth Quarterly EM&A report
for the Contract which summarizes the monitoring results and audit findings of
the EM&A programme during the reporting period from 1 December 2015to 29 February 2016.
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
December 2015
January
2016
February
2016
Air
Quality
1-hr TSP
4, 10, 15, 21, 24 and 30
5, 11, 15, 21 and 27
2, 6, 12, 18 and 24
24-hr TSP
AMS5: 3, 9, 14, 18, 23 and 29
AMS6: 3, 9, 14, 18 and 29
AMS5: 4, 8, 14, 20
and 26
AMS6: 5, 8, 14, 20 and 26
AMS5: 1, 5, 17, 18,
23 and 29
AMS6: 1, 5, 11, 17, 23 and 29
Noise
10, 15, 21 and 30
5, 11, 21 and 27
2, 12, 18 and 24
Water
Quality
2, 4, 7, 9, 11, 14, 16, 18, 21, 23, 25, 28
and 30
1, 4, 6, 8, 11, 13, 15, 18, 20, 22, 25, 27
and 29
1, 3, 5, 11, 13, 15, 17, 19, 22, 24, 26 and
29
Chinese
White Dolphin
2, 7, 9 and 15
8, 11, 13 and 19
2, 3, 16 and 22
Mudflat
Monitoring (Ecology)
5, 12, 13, 16, 19
and 20
--
--
Mudflat
Monitoring (Sedimentation rate)
1
--
--
Site Inspection
2, 9, 17, 23 and 29
6, 13, 20 and 29
3, 12, 15 and 26
Due to weather
condition/boat availability, the dolphin monitoring schedule was rescheduled
from 10 December 2015 to 9 December 2015, from 14 December 2015 to 15 December
2015, from 12 January 2016 to 13 January 2016, from 18 January 2016 to 19
January 2016, from 1 February 2016 to 2 February 2016.
Due to
clash of schedule, the dolphin monitoring schedule was rescheduled from 4
January 2016 to 11 January 2016.
Due to power interruption of HVS at
AMS6 on 23 December 2015, the 24-hr TSP monitoring result obtained at AMS6 on
23 December 2015 was considered invalid.
Due to malfunctioning
of timer of HVS at AMS6 on 4 January 2016, the 24-hr TSP monitoring at AMS6 on
4 January 2016 was cancelled. The timer was replaced and was used for 24hr TSP
monitoring on 5 January 2016.
The monitoring period
of the 24-hr TSP monitoring on 11 February 2016 was less than 24 hours due to
malfunction of HVS at AMS5. Therefore, the 24-hr TSP monitoring on 11 February
2016 was rescheduled to 18 February 2016.
As
informed by the Contractor on 29 January 2016, no marine work was undertaken by
Contract no. HY/2011/03 during the Chinese New Year Period from 7 - 10 February
2016.Therefore, the scheduled
impact water quality monitoring on 8 February 2016 was cancelled and water
quality monitoring on 10 and 12 February 2016 were rescheduled to 11 and 13
February 2016.
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
5
0
24-hr TSP
0
0
Noise
Leq
(30 min)
0
0
Water
Quality
Suspended
solids level (SS)
1
1
Turbidity
level
0
2
Dissolved
oxygen level (DO)
0
0
Dolphin
Monitoring
Quarterly
Analysis (Dec 2015 to Feb 2016)
0
1
The Environmental Team investigated all
exceedances and found that they were not project related.
All investigation reports for exceedances of the
Contract have been submitted to ENPO/IEC for comments and/or follow up to
identify whether the exceedances occurred related to other HZMB contracts.
Implementation of Mitigation Measures
Site inspections were carried out on a weekly
basis to monitor the implementation of proper environmental pollution control
and mitigation measures for the Project.Potential environmental impacts due to the construction activities were
monitored and reviewed.
Complaint Log
There
were no complaints received in relation to the environmental impacts during the
reporting period.
Notifications of Summons and Prosecutions
There were no notifications of summons or
prosecutions received during this reporting period.
Reporting Changes
This report has been developed in compliance
with the reporting requirements for the quarterly summary EM&A reports as
required by the Updated EM&A Manual for HKLR (Version 1.0).
The proposal for the change of Action Level and
Limit Level for suspended solid and turbidity was approved by EPD on 25 March
2013.
The revised Event and Action Plan for dolphin monitoring was approved by EPD on 6 May 2013.
The original monitoring station at IS(Mf)9
(Coordinate- East:813273, North 818850) was observed inside the perimeter silt
curtain of Contract HY/2010/02 on 1 July 2013, as such the original impact
water quality monitoring location at IS(Mf)9 was temporarily shifted outside
the silt curtain. As advised by the
Contractor of HY/2010/02 in August 2013, the perimeter silt curtain was shifted
to facilitate safe anchorage zone of construction barges/vessels until end of
2013 subject to construction progress.Therefore, water quality monitoring station IS(Mf)9 was shifted to
813226E and 818708N since 1 July 2013.According to the water quality monitoring team’s observation on 24 March
2014, the original monitoring location of IS(Mf)9 was no longer enclosed by the
perimeter silt curtain of Contract HY/2010/02.Thus, the impact water quality monitoring
works at the original monitoring location of IS(Mf)9 has been resumed since 24
March 2014.
Transect lines 1, 2, 7, 8, 9 and 11 for dolphin
monitoring have been revised due to the obstruction of the permanent structures
associated with the construction works of HKLR and the southern viaduct of
TM-CLKL, as well as provision of adequate buffer distance from the Airport
Restricted Areas.The EPD issued a
memo and confirmed that they had no objection on the revised transect lines on
19 August 2015.
1.1.2The 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.
1.1.3China State Construction
Engineering (Hong Kong) Ltd. was awarded by Highways Department (HyD) as the
Contractor to undertake the construction works of Contract No. HY/2011/03.The Contract is part of the HKLR
Project and HKBCF Project, these projects are considered to be “Designated
Projects”, under Schedule 2 of the Environmental Impact Assessment (EIA)
Ordinance (Cap 499) and EIA Reports (Register No. AEIAR-144/2009 and
AEIAR-145/2009) were prepared for the Project.The current Environmental Permit (EP)
EP-352/2009/D for HKLR and EP-353/2009/K for HKBCF were issued on 22 December
2014 and 11 April 2016, respectively. These documents are available through the
EIA Ordinance Register. The construction
phase of Contract was commenced on 17 October
2012.Figure 1.1 shows the project site boundary.
1.1.5This is the fourteenthQuarterly Environmental Monitoring and Audit
(EM&A) report for the Contract which summarizes the monitoring results and
audit findings of the EM&A programme during the reporting period from 1
December 2015 to 29 February 2016.
1.2.1The 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.
1.3Construction
Programme
1.3.1A copy of the Contractor’s construction programme
is provided in Appendix B.
1.4Construction Works Undertaken During
the Reporting Period
1.4.1A 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 1.1Construction
Activities during Reporting Period
Description of Activities
Site Area
Dismantling/trimming of
temporary 40mm stone platform for construction of seawall
Portion X
Filling works behind
stone platform
Portion X
Construction of seawall
Portion X
Loading and unloading
of filling materials
Portion X
Band drains
installation
Portion X
Excavation and lateral
support works for Scenic Hill Tunnel (Cut & Cover Tunnel)
Portion X
Socket H-Piling work
for Scenic Hill Tunnel (Cut & Cover Tunnel)
Portion X
Excavation for diversion of culvert PR10
Portion X
Construction of tunnel
box structure at Scenic Hill Tunnel (Cut & Cover Tunnel)
Portion X
Pipe piling works for
HKBCF to Airport Tunnel East (Cut & Cover Tunnel)
Portion X
Excavation for HKBCF to
Airport Tunnel
Portion X
Sheet Piling Works for HKBCF to Airport Tunnel East (Cut & Cover
Tunnel)
Portion X
Socket H-Piling Works for HKBCF to Airport Tunnel East (Cut &Cover
Tunnel)
Portion X
Superstructure works
for Scenic Hill Tunnel West Portal Ventilation building
West Portal
Pipe piling works for HKBCF to Airport Tunnel West (Cut & Cover
Tunnel)
Airport Road
Works for diversion
Kwo Lo Wan Road and Airport Road
Utilities detection
Airport Road/ Airport Express Line/ East Coast Road
Establishment of Site
Access
Airport Road/ Airport Express Line/ East Coast Road
Canopy pipe drilling / Box Jacking underneath Airport
Express Line
Excavation and lateral
support works at shaft 3 extension north shaft
Kwo Lo Wan Road
Excavation and Lateral
Support Works for HKBCF to Airport Tunnel West (Cut & Cover Tunnel)
Airport Road
Utility culvert
excavation
Portion Y
Sub-structure &
superstructure works for Highway Operation and Maintenance Area Building
Portion Y
2EM&A Requirement
2.1Summary of
EM&A Requirements
2.1.1The 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.
2.1.2A 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.
Three times per week during
mid-ebb and mid-flood tides (within ± 1.75 hour of the predicted time)
3
(1 m below water surface,
mid-depth and 1 m above sea bed, except where the water depth is less than 6
m, in which case the mid-depth station may be omitted.Should the water depth be less than 3
m, only the mid-depth station will be monitored).
Dolphin
Line-transect
Methods
Northeast Lantau survey
area and Northwest Lantau survey area
Twice per month
--
Mudflat
Horseshoe crabs, seagrass beds, intertidal soft shore communities,
sedimentation rates and water quality
2.2.1Table 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)
2.2.2The Action and Limit
Levels for water quality monitoring are given as in Table 2.3.
Table 2.3Action
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.
2.2.3The Action and Limit
Levels for dolphin monitoring are shown in Tables
2.4 and 2.5.
Table 2.4Action
and Limit Level for Dolphin Impact Monitoring
North
Lantau Social Cluster
NEL
NWL
Action Level
STG < 70% of baseline
&
ANI < 70% of baseline
STG < 70% of baseline
&
ANI< 70% of baseline
Limit Level
STG < 40% of baseline
&
ANI < 40% of baseline
Remarks:
(1)STG means quarterly average encounter rate of
number of dolphin sightings.
(2)ANI means quarterly average encounter rate of
total number of dolphins.
(3)For North Lantau Social Cluster, AL will be triggered
if either NEL or NWL fall below the criteria; LL will be triggered if both NEL
and NWL fall below the criteria.
Table 2.5Derived
Value of Action Level (AL) and Limit Level (LL)
North
Lantau Social Cluster
NEL
NWL
Action Level
STG < 4.2& ANI < 15.5
STG < 6.9 & ANI
< 31.3
Limit Level
(STG < 2.4 & ANI
< 8.9) and (STG < 3.9 & ANI < 17.9)
Remarks:
(1)STG means quarterly average encounter rate of
number of dolphin sightings.
(2)ANI means quarterly average encounter rate of
total number of dolphins.
(3)For North Lantau Social Cluster, AL will be
triggered if either NEL or NWL fall below the criteria; LL will be triggered if
both NEL and NWL fall below the criteria.
2.3Event Action Plans
2.3.1The Event Actions Plans for air quality, noise, water quality and
dolphin monitoring are annexed in Appendix D.
2.4Mitigation Measures
2.4.1Environmental
mitigation measures for the contract were recommended in the approved EIA
Report.Appendix Elists the recommended mitigation measures and the
implementation status.
3Environmental Monitoring and Audit
3.1Implementation of
Environmental Measures
3.1.1In response to the site audit findings, the
Contractor have rectified all observations identified in environmental site
inspections undertaken during the reporting period. Details of site audit
findings and the corrective actions during the reporting period are presented in
Appendix
F.
3.1.2A summary of the Implementation Schedule of
Environmental Mitigation Measures (EMIS) is presented in Appendix E.
3.1.3Regular marine travel route for
marine vessels were implemented properly in accordance to the submitted plan
and relevant records were kept properly.
3.1.4Dolphin Watching Plan was
implemented during the reporting period.
No dolphins inside the silt curtain were observed. The relevant records were
kept properly.
3.2.1The monitoring results for 1-hour TSP and
24-hour TSP are summarized in Tables 3.1 and 3.2
respectively. Detailed impact air quality monitoring results and relevant graphical
plots are presented in Appendix G.
Table 3.1 Summary
of 1-hour TSP Monitoring Results Obtained During the Reporting Period
Reporting Period
Monitoring
Station
Average (mg/m3)
Range (mg/m3)
Action Level (mg/m3)
Limit Level (mg/m3)
December 2015
AMS5
188
103 - 390
352
500
AMS6
191
83 - 385
360
January 2016
AMS5
174
81 -
445
352
AMS6
158
76 -
291
360
February 2016
AMS5
138
88 -
213
352
AMS6
134
82 -
181
360
Table 3.2 Summary
of 24-hour TSP Monitoring Results Obtained During the Reporting Period
Reporting Period
Monitoring
Station
Average (mg/m3)
Range (mg/m3)
Action Level (mg/m3)
Limit Level (mg/m3)
December 2015
AMS5
54
25 -
79
164
260
AMS6
88
65 -
114
173
January 2016
AMS5
43
19 -
65
164
AMS6
59
28 -
94
173
February 2016
AMS5
51
18 -
102
164
AMS6
73
27 -
134
173
Three Action Level exceedances 1-hr TSP level at AMS5 and two Action
Level exceedances of 1-hr TSP level at AMS6 were recorded during the reporting
period. Record of “Notification
of Environmental Quality Limit Exceedances” is provided in Appendix M.
3.2.2There were no
Action and Limit Level exceedances of 24-hour TSP were recorded at AMS5 and
AMS6 during the reporting period.
3.3Noise Monitoring Results
3.3.1The monitoring results for construction noise
are summarized in Table 3.3 and the
monitoring results and relevant graphical plots for this reporting
period are provided in Appendix H.
Table 3.3 Summary of Construction Noise
Monitoring Results Obtained During the Reporting Period
3.4.1Impact 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 inAppendix I.
3.4.2During the reporting period, Limit Level
exceedances of turbidity level were recorded at stations IS8 and SR4 during
mid-flood tide on 5 February 2016 respectively. An Action Level exceedance of
suspended solids level was recorded at station IS8 and a Limit Level exceedance
of suspended solid was recorded at station SR4 during mid-flood tide on 5
February 2016. Record of “Notification of Environmental Quality Limit Exceedances” is
provided in Appendix M. No exceedance of Action Level for turbidity level was recorded. No exceedances of Action and Limit Level for
dissolved oxygen level were recorded.
3.4.3Water 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.
3.5.2Encounter rate analysis –
Encounter rates of Chinese White Dolphins (number of on-effort sightings per
100 km of survey effort, and total number of dolphins sighted on-effort per 100
km of survey effort) were calculated in NEL and NWL survey areas in relation to
the amount of survey effort conducted during each month of monitoring survey.
Dolphin encounter rates were calculated in two ways for comparisons with the
HZMB baseline monitoring results as well as to AFCD long-term marine mammal
monitoring results.
3.5.3Firstly, 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).
3.5.4Secondly, the encounter rates
were calculated using both primary and secondary survey effort collected under
Beaufort 3 or below condition as in AFCD long-term monitoring study.The encounter rate of sightings and
dolphins were deduced by dividing the total number of on-effort sightings and
total number of dolphins (ANI) by the amount of survey effort for the present
quarterly period.
3.5.5Quantitative grid analysis on
habitat use – To conduct quantitative grid analysis of habitat use, positions
of on-effort sightings of Chinese White Dolphins collected during the quarterly
impact phase monitoring period were plotted onto 1-km2 grids among
Northwest Lantau (NWL) and Northeast (NEL) survey areas on GIS.Sighting densities (number of on-effort
sightings per km2) and dolphin densities (total number of dolphins
from on-effort sightings per km2) were then calculated for each 1 km
by 1 km grid with the aid of GIS.Sighting density grids and dolphin density grids were then further
normalized with the amount of survey effort conducted within each grid.The total amount of survey effort spent
on each grid was calculated by examining the survey coverage on each
line-transect survey to determine how many times the grid was surveyed during
the study period.For example, when
the survey boat traversed through a specific grid 50 times, 50 units of survey
effort were counted for that grid.With the amount of survey effort calculated for each grid, the sighting
density and dolphin density of each grid were then normalized (i.e. divided by
the unit of survey effort).
3.5.6The 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%
whereS =
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
3.5.7Behavioural analysis – When
dolphins were sighted during vessel surveys, their behaviour was observed.Different activities were categorized
(i.e. feeding, milling/resting, traveling, socializing) and recorded on
sighting datasheets.This data was
then input into a separate database with sighting information, which can be
used to determine the distribution of behavioural data with a desktop GIS.Distribution of sightings of dolphins
engaged in different activities and behaviours would then be plotted on GIS and
carefully examined to identify important areas for different activities of the
dolphins.
3.5.9During the period of December 2015 to
February 2016, six sets of systematic line-transect vessel surveys were
conducted to cover all transect lines in NWL and NEL survey areas twice per
month.
3.5.10From these surveys, a total of 907.45 km of survey effort was collected, with95.1% 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, 347.07 km and 560.38 km of survey effort were conducted in NEL and NWL
survey areas respectively.
3.5.11The total survey effort conducted on
primary lines was 655.90 km, while the effort on secondary lines
was 251.55 km.Survey effort conducted on both primary and secondary lines
were considered as on-effort survey data.A summary table of the survey
effort is shown in Annex I of Appendix J.
3.5.12During the six sets of monitoring surveys in December 2015
to February 2016, a total of 14 groups of 57 Chinese
White Dolphins were sighted. A
summary table of the dolphin sightings is shown inAnnex II of Appendix J.
3.5.13For the present quarterly period,
all except onedolphin sighting
were made during on-effort search,
and ten of the thirteen on-effort dolphin sightings were made on primary lines.Moreover, all dolphin groups were sighted in NWL, but none was sighted at all in NEL. In fact,
since August 2014, only one sighting of a lone dolphin was made in NEL during
HKLR03 monitoring surveys.
Distribution
3.5.14Distribution of dolphin sightings
made during monitoring surveys in December
2015 to February 2016 is shown in Figure 1 of Appendix J. Dolphin sightings made in the present quarter were mostly located to the
north of Lung Kwu Chau, while a few other sightings were also made near Pillar
Point and Sha Chau (Figure 1 of Appendix J).
3.5.15Notably, two dolphin groups were sighted near
the northern landfall of Tuen Mun-Chek Lap Kok Link (TMCLKL) as well as near
Shum Wat near the Hong Kong Link Road (HKLR) respectively (Figure 1 of Appendix J).On the other hand, all other dolphin sightings were made far away from
the HKLR03/HKBCF reclamation sites as well as along the southern viaduct of
TMCLKL during the present quarterly period (Figure 1 of Appendix J).
3.5.16Sighting distribution of the present impact phase monitoring period (December 2015 to February 2016) was compared to the one during the baseline monitoring period
(September to November 2011).In the
present quarter, dolphins have disappeared from the NEL region, which was in
stark contrast to their frequent occurrence around the Brothers Islands, near
Shum Shui Kok and in the vicinity of HKBCF reclamation site during the baseline
period(Figure 1 of Appendix J). The nearly complete abandonment of NEL
region by the dolphins has been consistently recorded in the past twelve
quarters of HKLR03 monitoring, which has resulted in zero to extremely low dolphin
encounter rate in this area.
3.5.17In NWL survey area, dolphin occurrence was
also drastically different between the baseline and impact phase periods.During the present impact monitoring
period, much fewer dolphins occurred in this
survey area than during the baseline period, when many dolphin groups were frequently
sighted between Lung Kwu Chau and Black Point,
around Sha Chau, near Pillar Point and to the west of the Chek Lap Kok Airport (Figure
1 of Appendix J).
3.5.18Another comparison in dolphin distribution was
made between the three quarterly periods of winter months in 2013-14, 2014-15
and 2015-16 (Figure 2of Appendix J). Among
the four winter periods, dolphins were regularly sighted in NEL in 2012-13, but
their usage there was dramatically reduced in 2013-14, and the dolphins have
completely avoided this area during the winter of 2014-15 and 2015-16 (Figure 2of Appendix J).
3.5.19On the other hand, dramatic
changes in dolphin distribution in NWL waters were also observed in the winter
months during the three quarterly periods (Figure
2 of Appendix J). In 2012-13 and 2013-14, dolphins
still regularly occurred throughout the NWL survey area, with higher
concentrations of sightings within Sha Chau and Lung Kwu Chau Marine Park, but
they appeared to avoid the waters to the north of the airport in 2013-14 where
they normally occurred in the previous winter.In 2014-15 and 2015-16, dolphin usage in
NWL was then dramatically reduced, with most sightings clustered around and to
the north of Lung Kwu Chau but rarely sighted elsewhere. Such temporal trend
indicated that dolphin usage in the NWL region has progressively diminished in
recent years.
Encounter Rate
3.5.20During the present three-month
study period, the encounter rates of Chinese White Dolphins deduced from the
survey effort and on-effort sighting data from the primary transect lines under
favourable conditions (Beaufort 3 or below) for each set of the surveys in NEL
and NWL are shown in Table 3.4.The average encounter rates deduced from the six
sets of surveys were also compared with the ones deduced from the baseline
monitoring period (September – November 2011) (See Table
3.5).
Table
3.4Dolphin
Encounter Rates (Sightings Per 100 km of Survey Effort) During Reporting Period
(December 2015 to February 2016)
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)
Encounter rate (STG)
(no. of on-effort dolphin sightings per 100 km of survey effort)
Encounter rate (ANI)
(no. of dolphins from all on-effort sightings per 100 km of survey effort)
Reporting Period
Baseline Monitoring Period
Reporting Period
Baseline Monitoring Period
Northeast Lantau
0.0
6.00 ± 5.05
0.0
22.19 ± 26.81
Northwest Lantau
2.64 ± 1.52
9.85 ± 5.85
10.98 ± 3.81
44.66 ± 29.85
Notes:
1) The encounter rates deduced from the baseline monitoring period have been
recalculated based only on the survey effort and on-effort sighting data made
along the primary transect lines under favourable conditions.
2)± denotes the standard deviation of the average
encounter rates.
3.5.21To 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 2.32 sightings and 9.11 dolphins per 100
km of survey effort respectively, while the encounter rates of sightings (STG)
and dolphins (ANI) in NEL were both nil for this
quarter.
3.5.22In NEL, the average dolphin encounter
rates (both STG and ANI) in the present three-month impact monitoring period
were both zero with no sighting made, and such extremely low occurrence of
dolphins in NEL have been consistently recorded in the past twelve quarters of
HKLR03 monitoring (Table 3.6). This is a serious concern as
the dolphin occurrence in NEL in the last eleven quarters (0.0-1.0 for ER(STG)
and 0.0-3.9 for ER(ANI)) have been exceptionally low when compared to the
baseline period (Table 3.6).Dolphins have almost vacated from NEL
waters since January 2014, with only two groups of five dolphins sighted there
since then despite consistent and intensive survey effort being conducted in
this survey area.
Table
3.6Comparison of Average
Dolphin Encounter Rates in Northeast Lantau Survey Area from All Quarters of
Impact Monitoring Period and Baseline Monitoring Period (Sep – Nov 2011)
Monitoring Period
Encounter rate (STG)
(no. of on-effort dolphin sightings per 100 km of survey effort)
Encounter rate (ANI)
(no. of dolphins from all on-effort sightings per 100 km of survey effort)
September-November 2011
(Baseline)
6.00 ± 5.05
22.19 ± 26.81
December 2012-February 2013 (Impact)
3.14 ± 3.21*
6.33 ± 8.64*
March-May
2013 (Impact)
0.42 ± 1.03
0.42 ± 1.03
June-August
2013 (Impact)
0.88 ± 1.36
3.91 ± 8.36
September-November 2013 (Impact)
1.01
± 1.59
3.77
± 6.49
December 2013-February 2014 (Impact)
0.45 ± 1.10*
1.34 ± 3.29*
March-May
2014 (Impact)
0.00
0.00
June-August 2014 (Impact)
0.42 ± 1.04
1.69 ± 4.15
September-November 2014 (Impact)
0.00
0.00
December 2014-February 2015 (Impact)
0.00*
0.00*
March-May 2015 (Impact)
0.00
0.00
June-August 2015 (Impact)
0.44 ± 1.08
0.44 ± 1.08
September-November 2015 (Impact)
0.00
0.00
December 2015-February 2016 (Impact)
0.00*
0.00*
Notes: 1) The encounter rates
deduced from the baseline monitoring period have been recalculated based only
on survey effort and on-effort sighting data made along the primary transect
lines under favourable conditions.
2) ± denotes the standard
deviation of the average encounter rates.
3)The encounter rates in
winter months were in blue and marked with asterisk.
3.5.23Moreover, the average dolphin encounter rates (STG and ANI) in NWL
during the present impact phase monitoring period were also much lower
(reductions of 73.2% and 75.4% respectively) than the ones recorded in the
3-month baseline period, indicating a dramatic decline in dolphin usage of this
survey area as well during the present impact phase period (Table 3.7).
3.5.24Even for the same winter quarters, the dolphin encounter rates in NWL
during the winters of 2014-2015 and 2015-16 were much lower than the ones
recorded in winters of 2012-13 and 2013-14 (Table 3.7).
3.5.25After a slight rebound in encounter rates in NWL in the previous
quarter, dolphin occurrence has dropped noticeably once again in the present quarter
back to a low level (especially for ER(ANI)) (Table 3.7).Such
temporal trend should be closely monitored in the upcoming monitoring quarters.
Table 3.7Comparison of Average Dolphin Encounter Rates in Northwest Lantau
Survey Area from All Quarters of Impact Monitoring Period and Baseline
Monitoring Period (Sep – Nov 2011)
Monitoring Period
Encounter rate
(STG)(no. of on-effort
dolphin sightings per 100 km of survey effort)
Encounter rate
(ANI)(no. of dolphins from all on-effort sightings per 100 km of survey
effort)
September-November 2011 (Baseline)
9.85 ± 5.85
44.66 ± 29.85
December 2012-February 2013 (Impact)
8.36 ± 5.03*
35.90 ± 23.10*
March-May 2013 (Impact)
7.75 ± 3.96
24.23 ± 18.05
June-August 2013 (Impact)
6.56 ± 3.68
27.00 ± 18.71
September-November
2013 (Impact)
8.04 ± 1.10
32.48 ± 26.51
December 2013-February 2014 (Impact)
8.21 ± 2.21*
32.58 ± 11.21*
March-May 2014 (Impact)
6.51 ± 3.34
19.14 ± 7.19
June-August 2014 (Impact)
4.74 ± 3.84
17.52 ± 15.12
September-November
2014 (Impact)
5.10 ± 4.40
20.52 ± 15.10
December 2014-February 2015 (Impact)
2.91 ± 2.69*
11.27 ± 15.19*
March-May 2015 (Impact)
0.47 ± 0.73
2.36 ± 4.07
June-August 2015 (Impact)
2.53 ± 3.20
9.21 ± 11.57
September-November
2015 (Impact)
3.94 ± 1.57
21.05 ± 17.19
December 2015-February 2016 (Impact)
2.64 ± 1.52*
10.98 ± 3.81*
Notes:
1) The encounter rates deduced from the
baseline monitoring period have been recalculated based only on survey effort
and on-effort sighting data made along the primary transect lines under
favourable conditions.
2) ± denotes the standard deviation of the average encounter rates.
3) The
encounter rates in winter months were in blue and marked with asterisk.
3.5.26As discussed recently in Hung (2015), the dramatic decline in
dolphin usage of NEL waters in the past few years (including the declines in
abundance, encounter rate and habitat use in NEL, as well as shifts of
individual core areas and ranges away from NEL waters) was possibly related to
the HZMB construction works that were commenced since 2012.It appeared that such noticeable decline
has already extended to NWL waters progressively in past few years.
3.5.27A 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).
3.5.28For the comparison between the baseline period and the present quarter
(thirteenth quarter of the impact phase being assessed), the p-values for the
differences in average dolphin encounter rates of STG and ANI were 0.0043 and
0.0275 respectively.If the alpha
value is set at 0.05, significant differences were detected between the
baseline and present quarters in both the average dolphin encounter rates of
STG and ANI.
3.5.29For comparison between the baseline period and the cumulative quarters in
impact phase (i.e. first thirteen quarters of the impact phase being assessed),
the p-values for the differences in average dolphin encounter rates of STG and
ANI were 0.00004 and 0.00001 respectively.Even if the alpha value is set at 0.00005, significant differences were
still detected in both the average dolphin encounter rates of STG and ANI (i.e.
between the two periods and the locations).
3.5.30As
indicated in both dolphin distribution patterns and encounter rates, dolphin
usage has been significantly reduced in both NEL and NWL survey areas during
the present quarterly period, and such low occurrence of dolphins has also been
consistently documented in previous quarters. This
raises serious concern, as the timing of the decline in dolphin usage in North
Lantau waters coincided well with the construction schedule of the HZMB-related
projects (Hung 2015).
3.5.31To ensure the continuous
usage of North Lantau waters by the dolphins, every possible measure should be
implemented by the contractors and relevant authorities of HZMB-related works
to minimize all disturbances to the dolphins.
Group
Size
3.5.32Group size of Chinese White Dolphins ranged from
one to ten individuals per group in North Lantau region during December 2015 to February 2016. 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 3.8Comparison
of Average Dolphin Group Sizes between Reporting Period (Dec 2015 – Feb 2016)
and Baseline Monitoring Period (Sep – Nov 2011)
Survey Area
Average Dolphin Group Size
Reporting Period
Baseline Monitoring Period
Overall
4.07 ± 3.22 (n = 14)
3.72 ± 3.13 (n = 66)
Northeast Lantau
N/A
3.18 ± 2.16 (n = 17)
Northwest Lantau
4.07 ± 3.22 (n = 14)
3.92 ± 3.40 (n = 49)
Note:
1)± denotes the standard deviation of the average
group size.
3.5.33The average dolphin group size in NWL waters during
December 2015 to February 2016 was slightly higher than the ones recorded
during the three-month baseline period (Table
3.8). Eight of the 14 groups were composed of 1-3 individuals only, while
three other groups were moderate in sizes with 5-6 individuals per group.Moreover, three large dolphin groups
with 8-10 individuals each were sighted during the present quarterly period.
3.5.34Distribution
of dolphins with larger group sizes (five individuals or more per group and ten
individuals per group) during the present quarter is shown in (Figure 3 of Appendix J), with
comparison to the one in baseline period.During the winter months of 2015-16, distribution of these moderately
large groups of dolphins were located to the north of Lung Kwu Chau, near
Pillar Point and near the northern landfall of TMCLKL (Figure 3 of Appendix J). This distribution pattern was very
different from the baseline period, when the larger dolphin groups were more
evenly distributed in NWL waters with a few more sighted in NEL waters (Figure 3 of Appendix J).
Habitat
Use
3.5.35From December 2015 to February 2016, the areas being
heavily utilized by Chinese White Dolphins was to the north
of Lung Kwu Chau, near Pillar Point and near the northern landfall of TMCLKL in
the North Lantau region (Figures 4a and 4bof Appendix J). All grids near
HKLR03/HKBCF reclamation sites as well as HKLR09 alignment did not record any
presence of dolphins during on-effort search in the present quarterly period,
but one grid (N12) overlapped with the northern landfall of TMCLKL recorded
moderately high dolphin densities (Figures 4bof Appendix J).
3.5.36It should be emphasized that the amount of survey effort collected in
each grid during the three-month period was fairly low (6-12 units of survey
effort for most grids), and therefore the habitat use pattern derived from the
three-month dataset should be treated with caution.A more complete picture of dolphin
habitat use pattern should be examined when more survey effort for each grid will be
collected throughout the impact phase monitoring programme.
3.5.37When
compared with the habitat use patterns during the baseline period, dolphin
usage in NEL and NWL has dramatically diminished in both areas during the
present impact monitoring period (Figure
5of Appendix J).During the baseline period, many grids between Siu Mo To and Shum Shui
Kok in NEL recorded moderately high to high dolphin densities, which was in
stark contrast to the complete absence of dolphins there during the present
impact phase period (Figure 5of Appendix J).
3.5.38The
density patterns were also very different in NWL between the baseline and impact
phase monitoring periods, with higher dolphin usage throughout the area,
especially around Sha Chau, near Black Point, to the west of the airport, as
well as between Pillar Point and airport platform during the baseline period.In contrast, mainly the
waters to the north of Lung Kwu Chau recorded high densities of dolphins during
the present impact phase period (Figure 5of Appendix J).
Mother-calf Pairs
3.5.39During
the present quarterly period, neither unspotted calf nor unspotted juvenile was sighted
with any female in the North Lantau region.
3.5.40The
absence of young calves in the present quarter was in stark contrast to their
regular occurrence in North Lantau waters during the baseline period.This should be of a serious concern, and
the occurrence of young calves in North Lantau waters should be closely
monitored in the upcoming quarters.
Activities and Associations with Fishing Boats
3.5.41One of the 14 dolphin groups were engaged in
feeding activity, while two other dolphin groups were engaged in socializing
activities.None of the dolphin
groups were engaged in traveling or milling/resting activity during the
three-month study period.
3.5.42The percentage of sightings associated with feeding
activities (7.1%) was much lower than the one recorded during the baseline
period (11.6%), while the one associated with socializing activities (14.2%)
during the present impact phase period was much higher than the one from the
baseline period (5.4%).However, it
should be noted the sample sizes on total numbers of dolphin sightings during
the present quarter (14 dolphin groups) was much lower than the baseline period
(66 dolphin groups).
3.5.43Distribution
of dolphins engaged in various activities during the present three-month period
is shown in Figure 6of Appendix J.The only dolphin group engaged in feeding
activity was sighted near Sha Chau, while the two groups engaged in socializing
activities were located to the north of Lung Kwu Chau and near the northern
landfall of TMCLKL.
3.5.44When compared to the baseline period, distribution
of various dolphin activities during the present impact phase monitoring period
was drastically different with a much more restricted area of occurrences of
these activities (Figure 6of Appendix J).
3.5.45As consistently recorded in the past monitoring
quarters, none of the 14 dolphin groups was found to
be associated with any operating fishing vessel in North Lantau waters during
the present impact phase period.
Summary
Photo-identification works
3.5.46From December 2015 to February 2016, over 1,500
digital photographs of Chinese White Dolphins were taken during the impact
phase monitoring surveys for the photo-identification work.
3.5.47In
total, 21 individuals sighted 48 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.
3.5.48The
majority of identified individuals were sighted only once or twice during the
three-month period, with the exception of six individuals (NL182, NL210, NL220,
NL284, NL286 and NL320) being 3-4 times and another two individuals (NL48 and
NL285) being sighted 5 times in the present quarter.
3.5.49For the
first time since such comparison has been made, none of the 21 individuals
sighted in HKLR03 monitoring surveys was sighted in West Lantau waters during
the HKLR09 monitoring surveys in the same quarter.The restricted movements of individuals
between North and West Lantau waters should be continuously monitored to
determine whether the presence of HKLR09 alignments has affected such
movements.
Individual range use
3.5.50Ranging patterns of the 21 individuals identified during
the three-month study period were determined by fixed kernel method, and are
shown in Annex VofAppendix J.
3.5.51All identified dolphins sighted in the present
quarter were utilizing NWL waters only, but have completely avoided NEL waters
where many of them have utilized as their core areas in the past (Annex Vof Appendix J).This is in contrary to the extensive
movements between NEL and NWL survey areas observed in the earlier impact
monitoring quarters as well as the baseline period.
3.5.52Moreover,
none of the 21 individuals have extended their range use to WL or SWL waters
during the present quarter, which was very different from the previous quarters
when frequent individual movements between the North and West Lantau waters
were observed.In the upcoming
quarters, individual range use and movements should be continuously monitored
to examine whether there has been any significant change in individual range
use, which could possibly be related to the HZMB-related construction works or
the physical presence of the bridge structures (see Hung 2015).
Action Level / Limit Level Exceedance
3.5.53There was one Limit Level (LL) exceedance of
dolphin monitoring for the quarterly monitoring data (between December 2015 –
February 2016).According to the
contractor’s information, the marine activities undertaken for HKLR03 during
the quarter of December 2015 to February 2016 included reclamation,
construction of surcharge, removal of surcharge materials, construction of
seawall, temporary drainage diversion, ground investigation and maintenance of
silt curtain.
3.5.54There is no evidence showing the current LL
non-compliance directly related to the construction works of HKLR03 (where the
amounts of working vessels for HKLR03 have been decreasing), although the
generally increased amount of vessel traffic in NEL 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
(CWD).In addition, the contractor
will implement proactive mitigation measures such as avoiding anchoring at
Marine Department’s designated anchorage site – Sham Shui Kok Anchorage (near
Brothers Island) as far as practicable.
3.5.55According to Monitoring of Chinese White Dolphins
in Southwest Lantau Waters – Fourth Quarterly Report (December 2015 to February
2016) which is available on ENPO’s website, with their primary ranges centered
in North and West Lantau waters, some individuals showed apparent range shifts
or extensions to Southwest Lantau waters in 2015-16.For example, three individual dolphins
(NL120, WL46 and WL221) indicated obvious shifts in their range use from NWL to
West Lantau (WL) and Southwest Lantau (SWL) waters. Moreover, many individuals
(e.g. NL212, NL260, WL200, SL55, WL232, WL237 and WL265) have extended their
ranges from WL waters to SWL waters.It remains to be seen whether some of these individuals have permanently
shifted their ranges away from their primary ranges in North Lantau, or begin
to spend more times in SWL waters as part of their ranges.
3.5.56ENPO updated that the
Hong Kong-Zhuhai-Macao Bridge Authority (HZMBA) for the Mainland section of
Hong Kong-Zhuhai-Macao Bridge (HZMB) has commenced an interim survey on
fisheries resources and CWD in the Mainland waters. ENPO presented the
preliminary findings of the HZMBA interim survey on CWD sighting and
photo-identification works which provide solid evidence that some CWD that were
previously more often sighted in HK waters have expanded their ranges into the
Mainland waters, and some with reduced usage in HK waters. These preliminary
data were mentioned in Monitoring of Chinese White Dolphins in Southwest Lantau
Waters – Fourth Quarterly Report (December 2015 to February 2016) which is
available on ENPO’s website.
3.5.57A 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).
3.5.58For the comparison between the baseline period and
the present quarter (13th quarter of the impact phase being
assessed), the p-value for the differences in average dolphin encounter rates
of STG and ANI were 0.0043 and 0.0275 respectively.If the alpha value is set at 0.05,
significant differences were detected between the baseline and present quarters
in both the average dolphin encounter rates of STG and ANI.
3.5.59For the comparison between the baseline period and
the cumulative quarters in impact phase (i.e. first thirteen quarters of the
impact phase being assessed), the p-value for the differences in average
dolphin encounter rates of STG and ANI were 0.00004 and 0.00001
respectively.Even if the alpha
value is set at 0.00005, significant differences were detected in both the
average dolphin encounter rates of STG and ANI (i.e. between the two periods
and the locations).
3.5.60The AFCD monitoring data during December 2015 to
February 2016 has been reviewed by the dolphin specialist.During the same quarter, no dolphin was
sighted from 144.19 km of survey effort on primary lines in NEL, while three
groups of eight dolphins were sighted from 121.56 km of survey effort on
primary lines in NWL. This review has confirmed that the low occurrence of
dolphins reported by the HKLR03 monitoring surveys in winter 2015-16 in NEL and
NWL survey area is accurate.
3.5.61All dolphin protective measures are fully and
properly implemented in accordance with the EM&A Manual. According to the
Marine Travel Route Plan, the travelling speed of vessels must not exceed 5
knots when crossing the edge of the proposed marine park. The Contractor will
continue to provide training for skippers to ensure that their working vessels
travel from source to destination to minimize impacts on Chinese White Dolphin
and avoid anchoring at Marine Department’s designated anchorage site - Sham
Shui Kok Anchorage (near Brothers Island) as far as practicable. Also, it is
recommended to complete the marine works of the Contract as soon as possible so
as to reduce the overall duration of impacts and allow the dolphins population
to recover as early as possible.
3.5.62A meeting was held on 20 April 2016 with attendance
of representative of Highways Department (HyD), ENPO, Resident Site Staff
(RSS), Environmental Team (ET) and dolphin specialist for Contract Nos.
HY/2010/02, HY/2011/03, HY/2012/07, HY/2012/08. Also, main Contractor for
Contract Nos. HY/2012/08 attended the meeting. The discussion/ recommendation
as recorded in the minutes of the meeting, which might be relevant to HKLR03
Contract are summarized below.
3.5.63It was concluded that the HZMB works is one of the
contributing factors affecting the dolphins. It was also concluded the
contribution of impacts due to the HZMB works as a whole (or individual marine
contracts) cannot be quantified nor separate from the other stress factors.
3.5.64The dolphin specialists
of the projects confirmed that the CWD sighting around
the North of Sha Chau and Lung Kwu Chau Marine Park (SCLKCMP) has significantly decreased, and it was apparently
related to the re-routing of high speed ferry (HSF) from Skypier.
3.5.65It was reminded that the ETs shall keep reviewing
the implementation status of the dolphin related mitigation measures and remind
the contractor to ensure the relevant measures were fully implemented.
3.5.66It was recommended that the marine works of HZMB
projects should be completed as soon as possible so as to reduce the overall
duration of impacts and allow the dolphins population to recover as early as
possible.
3.5.67It was also recommended that the marine works
footprint (e.g., reduce the size of peripheral silt curtain) and vessels for
the marine works should be reduced as much as possible, and vessels idling /
mooring in other part of the North Lantau
shall be avoided whenever possible.
3.5.68It was suggested that the protection measures
(e.g., speed limit control) for the proposed Brothers Marine Park (BMP) shall
be brought forward as soon as possible before its establishment so as to
provide a better habitat for dolphin recovery. It was noted that under the
Regular Marine Travel Route Plan, the contractors have committed to reduce the
vessel speed in BMP. HyD updated that the draft map of the proposed BMP was
gazetted in February 2016. The ETs were reminded to update the BMP boundary in
the Regular Marine Travel Route Plan.
3.5.69There was a discussion on exploring possible
further mitigation measures, for example, controlling the underwater noise. It
was noted that the EIA reports for the projects suggested several mitigation
measures, all of which have been implemented.
3.6Mudflat Monitoring Results
Sedimentation
Rate Monitoring
3.6.1The baseline sedimentation rate
monitoring was in September 2012 and impact sedimentation rate monitoring was
undertaken on 1
December 2015. The mudflat surface levels at the four
established monitoring stations and the corresponding XYZ HK1980 GRID
coordinates are presented in Table 3.9 and Table 3.10.
Table 3.9Measured
Mudflat Surface Level Results
Baseline Monitoring
(September 2012)
Impact Monitoring
(December 2015)
Monitoring Station
Easting
(m)
Northing (m)
Surface Level
(mPD)
Easting
(m)
Northing (m)
Surface Level
(mPD)
S1
810291.160
816678.727
0.950
810291.172
816678.729
1.052
S2
810958.272
815831.531
0.864
810958.261
815831.520
0.974
S3
810716.585
815953.308
1.341
810716.586
815953.312
1.475
S4
811221.433
816151.381
0.931
811221.460
816151.373
1.071
Table 3.10Comparison
of Measurement
Comparison of measurement
Remarks and Recommendation
Monitoring Station
Easting
(m)
Northing (m)
Surface Level
(mPD)
S1
0.012
0.002
0.102
Level continuously increased
S2
-0.011
-0.011
0.110
Level continuously increased
S3
0.001
0.004
0.134
Level continuously increased
S4
0.027
-0.008
0.140
Level continuously increased
3.6.2This measurement result was generally and relatively higher than the
baseline measurement at S1, S2,
S3 and S4. The mudflat level is continuously increased.
Water
Quality Monitoring
3.6.3The 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.
3.6.4Impact
water quality monitoring in San Tau (monitoring station SR3) was conducted in
December 2015. The monitoring parameters included dissolved oxygen (DO),
turbidity and suspended solids (SS).
3.6.5The
Impact monitoring result for SR3 were extracted and summarised below:
Table 3.11Impact
Water Quality Monitoring Results (Depth Average)
Date
Mid Ebb Tide
Mid Flood Tide
DO (mg/L)
Turbidity
(NTU)
SS (mg/L)
DO (mg/L)
Turbidity
(NTU)
SS (mg/L)
2-Dec-15
6.56
7.35
7.20
6.51
9.50
10.40
4-Dec-15
6.29
5.95
6.40
6.71
4.85
8.40
7-Dec-15
6.31
6.40
6.40
6.38
4.75
4.75
9-Dec-15
6.30
9.55
10.50
6.47
6.60
8.30
11-Dec-15
6.34
8.35
10.35
6.22
6.55
7.80
14-Dec-15
6.62
9.95
10.25
6.61
8.60
10.70
16-Dec-15
7.22
9.55
10.70
6.75
12.05
13.70
18-Dec-15
7.16
5.80
8.70
7.38
8.20
6.55
21-Dec-15
6.78
5.20
7.30
6.98
4.10
9.25
23-Dec-15
6.86
7.75
9.55
6.81
6.40
8.50
25-Dec-15
7.03
4.00
4.30
6.97
4.55
4.65
28-Dec-15
6.90
7.60
9.10
7.14
10.30
11.65
30-Dec-15
7.12
10.05
10.45
6.94
6.80
7.85
Average
6.73
7.50
8.55
6.76
7.17
8.65
Mudflat Ecology Monitoring
Sampling
Zone
3.6.6In order to collect baseline
information of mudflats in the study site, the study site was divided into three sampling zones (labeled as TC1, TC2, TC3) in Tung Chung Bay and one zone in San Tau (labeled as ST) (Figure 2.1 of Appendix O). The horizontal length of
sampling zones TC1, TC2, TC3 and ST were about 250 m, 300 m, 300 m and 250 m,
respectively. Survey of horseshoe crabs, seagrass beds and intertidal communities
were conducted in every sampling zone. The present survey was conducted in December 2015 (totally 6 sampling days between 5thand 20thDecember 2015).
Horseshoe
Crabs
3.6.7Active search method wasconducted for
horseshoe crab monitoringby two experienced surveyors at every sampling
zone. During the search period, any accessible and
potential area would be investigated for any horseshoe crab individuals within
2-3 hours in low tide period (tidal level
below 1.2 m above Chart Datum (C.D.)). Once a horseshoe crab individualwas found, the
species was identified referencing to Li (2008). The prosomal
width, inhabiting substratumand respective
GPS coordinate were recorded.A photographic
record was taken for
future investigation. Any grouping
behavior of individuals, if found, was recorded. The horseshoe crab surveys were conducted on 16th (for TC3
and ST) and 20th (for TC1 and TC2) December 2015. The weather was
cloudy and cold during the survey.
Seagrass Beds
Active search method wasconducted for seagrass bedmonitoring
by two experienced surveyors at every sampling zone. During the search period, any
accessible and potential area would be investigated for any seagrass beds
within 2-3 hours in low tide period. Once seagrass
bedwas found, the species, estimated area, estimated coverage percentage and respective GPS coordinate were recorded.A photographic
record was taken for
future investigation. The seagrass beds surveys were
conducted on 16th (for TC3 and ST) and 20th (for TC1 and TC2)
December 2015. The weather was cloudy and cold during the survey.
Intertidal Soft Shore
Communities
3.6.8The intertidal soft shore
community surveys were conducted in low tide period 5th (for TC1),
12th (for TC2), 13th (for ST) and 19th
December 2015 (for TC3) At each sampling zone, three 100m horizontal transects were laid
at high tidal level (H: 2.0 m above C.D.), mid
tidal level (M: 1.5 m above C.D.) and low tidal
level (L: 1.0 m above C.D.). Along every horizontal transect, ten random quadrats (0.5 m x 0.5m) were placed.
3.6.9Inside a quadrat, any visible
epifauna were collected and were in-situ identified to
the lowest practical taxonomical resolution. Whenever possible a hand core sample (10 cm internal diameter ´ 20 cm depth) of sediments was collected in the quadrat.The core sample was gently washed through a sieve of mesh size 2.0 mmin-situ. Any
visible infauna were collected and identified. Finally the top 5 cm surface
sediments were dug for visible infauna
in the quadrat regardless of hand core sample was taken.
3.6.10All collected fauna were
released after recording except some tiny individuals that are too small to be identified on site. These
tiny individuals were takento laboratory for identification under dissecting microscope.
3.6.11The taxonomic classification
was conducted in accordance to the following references: Polychaetes: Fauchald (1977), Yang and Sun (1988); Arthropods: Dai and Yang (1991), Dong (1991);
Mollusks: Chan and Caley (2003), Qi (2004).
Data
Analysis
3.6.12Data collected from direct search and core
sampling was pooled in every quadrat for data analysis. Shannon-Weaver
Diversity Index (H’) and Pielou’s Species Evenness (J) were calculated for
every quadrat using the formulae below,
H’= -Σ ( Ni / N ) ln ( Ni / N ) (Shannon and Weaver,
1963)
J = H’ / ln
S, (Pielou, 1966)
where S is the total number of species in the sample,
N is the total number of individuals, and Ni is the number of individuals of
the ith species.
Mudflat Ecology Monitoring Results and Conclusion
Horseshoe
Crabs
3.6.13In general, two species of horseshoe crab Carcinoscorpius
rotundicauda (total 2 ind.) and Tachypleus tridentatus (total 6 ind.) were
recorded. The total number of sight record
was very low due to cold, dry season. Individuals were found on either fine sand or soft mud. Every sight record consisted of one individual only hence no grouping
was observed. Photo records were shown in Figure
3.1of Appendix
Owhile the complete records of horseshoe crab
survey in every sampling
zone were shown inAnnex II of Appendix O.
3.6.14One newly hatched individual (prosomal width 6.31 mm) was found in TC1 (Figure 3.1 of Appendix O) on ST shore
(GPS coordinate: 22° 17.385' N, 113° 55.460' E). Since morphological
identification could not be conducted in-situ
due to too small size. This record was excluded from the data analysis of either horseshoe crab species.
3.6.15Table 3.1 of
Appendix Osummarizes the survey
results of horseshoe crab in present survey. For Carcinoscorpius rotundicauda, there was
one individual in TC3 and ST only. The search record was0.3ind.
hr-1 person-1 in both sampling zones. The size of individuals
was quite big with prosomal width 117.37-178.17 mm.
3.6.16For Tachypleus
tridentatus, it could be found in TC1 (1
ind.), TC3 (3 ind.) and ST (2 ind.). The search records were0.3ind.
hr-1 person-1, 0.8ind. hr-1
person-1and0.5 ind. hr-1 person-1in TC1, TC3 and ST respectively.The size of individuals
in ST (mean prosomal width 94.08 mm) was larger than that of TC1 (prosomal
width 39.30 mm) and TC3 (mean prosomal width 41.98 mm).
3.6.17In the previous survey of March 2015, there was one important finding
that a mating pair of Carcinoscorpius rotundicauda was found in ST (prosomal width:
male 155.1 mm, female 138.2 mm)(Figure 3.2 of Appendix O). It indicated the importance of ST as a breeding
ground of horseshoe crab. Moreover, two moults of Carcinoscorpius rotundicauda were found in TC1 with similar prosomal width
130-140 mm (Figure 3.2 of Appendix O). It reflected that a certain numbers of moderately
sized individuals inhabited the sub-tidal habitat of Tung Chung Wan after its
nursery period on soft shore. These individuals might move onto soft shore
during high tide for feeding, moulting and breeding. Then it would return to sub-tidal
habitat during low tide. Because the mating pair should be inhabiting sub-tidal
habitat in most of the time. The record was excluded from the data analysis to
avoid mixing up with juvenile population living on soft shore. In present survey the records of the two big individuals of Carcinoscorpius rotundicauda (prosomal
width 117.37 mm and 178.17 mm) were excluded from data analysis according to
the same principle.
3.6.18No marked individual of horseshoe crab was recorded
in present survey. Some marked individuals were found in
previous surveys conducted in
September 2013, March 2014 and September 2014. All of them were
releasedthrough a conservation programme conducted by Prof. Paul Shin
(Department of Biology and Chemistry, The City University of Hong Kong (CityU)). It was a re-introduction trial of artificial bred horseshoe crab
juvenile at selected sites. So that the horseshoe
crabs population might be restored in the natural habitat. Through a personal
conversation with Prof. Shin, about 100 individuals were released in the
sampling zone ST on 20 June 2013. All of them were marked with color tape and
internal chip detected by specific chip sensor. There should be second round of
release between June and September 2014 since new marked individuals were found
in the survey of September 2014.
3.6.19The artificial bred individuals, if found,
would be excluded from the results of present monitoring programme in order to
reflect the changes of natural population. However, the mark on their prosoma
might have been detached during moulting after a certain period of release. The
artificially released individuals were no longer distinguishable from the
natural population without the specific chip sensor. The survey data collected
would possibly cover both natural population and artificially bred individuals.
Population
difference among the sampling zones
3.6.20Figures 3.3 and 3.4 of Appendix O show the changes of number of individuals, mean prosomal width and
search record of horseshoe crabs Carcinoscorpius rotundicauda and Tachypleus
tridentatus respectively in every sampling zone along the sampling months.
In general, higher search records (i.e. number of individuals)
of both species were always found in ST followed by TC3 from September 2012 to
June 2014. Then the search record in TC3 was even higher than that in ST from
September 2014 to June 2015. In September 2015, the search records were similar
in TC3 and ST. For TC1, the search record was at low to medium level and
fluctuated slightly along the sampling months. In contrast, much lower
search record was found in TC2 (2 ind. in September 2013, 1 ind. in March,
June, September 2014, March and June 2015, 4 ind. in Sep. 2015). For spatial
difference of horseshoe crab size, larger individuals were usually found in ST
while smaller individuals were usually found in TC3.
3.6.21Throughout the monitoring period
conducted, it was obvious
that TC3 and ST (western shore of Tung Chung Wan) 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 a suitable nursery ground especially TC2. Possible factors were less area
of suitable substratum (especially TC1) and higher human disturbance (TC1 and
TC2: close to urban district and easily accessible). In TC2, large daily
salinity fluctuation was a possible factor either since it was flushed by two
rivers under tidal inundation. The individuals inhabiting TC1 and TC2 were
confined in small moving range due to limited area of suitable substrata during
the nursery period.
Seasonal variation of horseshoe crab population
3.6.22Throughout the monitoring period
conducted, the search record of horseshoe crab declined obviously during dry
season especially December (Figures 3.3 and 3.4 of Appendix O). In
December 2013, no individual of horseshoe crab was
found. In December 2014, 2 individuals of Carcinoscorpius rotundicauda and 8
individuals of Tachypleus
tridentatus were found only.In present survey (December 2015), 2
individuals of Carcinoscorpius rotundicauda, 6 individuals of Tachypleus tridentatus and one
newly hatched, unidentified individual were found only. The horseshoe crabs were inactive
and burrowed in the sediments during cold weather (<15 ºC). Similar results of low search record in dry season were reported in a
previous territory-wide survey of horseshoe crab. For example, the search
records in Tung Chung Wan were 0.17 ind. hr-1
person-1and 0.00 ind. hr-1 person-1in wet season and dry season respectively (details
see Li, 2008). After the dry season, the search record increased with the
warmer climate.
3.6.23Between the sampling months
September 2012 and December 2013, Carcinoscorpius
rotundicauda was a less common species relative to Tachypleus tridentatus. Only 4 individuals were ever recorded in ST in December 2012. This
species had ever been believed of very low density in ST hence the encounter
rate was very low. Since March. 2014, it was found in all sampling zones with
higher abundance in ST. Based on its average size (mean prosomal width
39.28-49.81 mm), it indicated that breeding and spawning of this species had
occurred about 3 years ago along the coastline of Tung Chun Wan. However, these
individuals were still small while their walking trails were inconspicuous.
Hence there was no search record in previous sampling months. From March 2014
to September 2015, more individuals were recorded due to larger size and higher
activity.
3.6.24For Tachypleus
tridentatus, sharp increase of number of individuals was recorded in ST with wet
season (from March to September 2013). According to a personal conversation
with Prof. Shin (CityU), his monitoring team had recorded similar increase of
horseshoe crab population during wet season. It was believed that the suitable
ambient temperature increased its conspicuousness. However similar pattern was
not recorded during the wet season of 2014. The number of individuals increased
in March and June 2014 followed by a rapid decline in September 2014. Then the
number of individuals showed a general decreasing trend from March 2014 to June
2015. Apart from natural mortality, migration from nursery soft shore to
subtidal habitat was another possible cause. Since the mean prosomal width of Tachypleus tridentatus continued to grow and reached about 50 mm since March 2014. Then it
varied slightly between 50-65 mm from September 2014 to September 2015. Most of
the individuals might have reached a suitable size strong enough to forage in
sub-tidal habitat.
3.6.25Since TC3 and ST were regarded as
important nursery ground for horseshoe crab, box plots of prosomal width of two
horseshoe crab species were constructed to investigate the changes of
population in details.
Box plot of
horseshoe crab populations in TC3
3.6.26Figure 3.5 of Appendix Oshows the changes of
prosomal width of Carcinoscorpius rotundicauda and Tachypleus tridentatus in TC3. As mentioned above, Carcinoscorpius rotundicauda was rarely found between September 2012 and December 2013 hence the
data were lacking. In March 2014, the major size (50% of individual records between upper and lower
quartile) ranged 40-60 mm while only few individuals were found. From March
2014 to September 2015, the size of major population decreased and more small
individuals were recorded after March of every year. It indicated new
rounds of successful breeding and spawning of Carcinoscorpius rotundicauda in TC3. It matched with the previous
mating record in ST in March 2015.
3.6.27For Tachypleus
tridentatus, the major size ranged 20-50 mm while the number of individuals found
fluctuated from September 2012 to June 2014. Then a slight but consistent
growing trend was observed. The prosomal width increased from 25-35 mm in
September 2014 to 35-65 mm in June 2015. As mentioned, the large individuals might have reached a suitable size for migrating from the
nursery soft shore to subtidal habitat. It accounted for the declined
population in TC3. In September and December 2015 (present survey), there was
only one and three individuals recorded.
Box plot of horseshoe
crab populations in ST
3.6.28Figure 3.6 of Appendix O shows the changes of prosomal width of Carcinoscorpius rotundicauda and Tachypleus tridentatus in ST. As mentioned
above, Carcinoscorpius rotundicauda was rarely
found between September 2012 and December 2013 hence the data were lacking.
From Mar. 2014 to Sep. 2015, the
size of major population decreased and more small individuals were recorded
after June of every year. It indicated new rounds of successful breeding
and spawning of Carcinoscorpius
rotundicauda in ST. It matched with the previous mating record in ST in
March 2015. Because most of newly hatched individuals (prosomal width ~5mm)
would take about half year to grow to a size with conspicuous walking trail.
3.6.29For Tachypleus tridentatus, a consistent growing trend was observed for the major population from
December 2012 to December 2014 regardless of change of search record. The
prosomal width increased from 15-30 mm to 55-70 mm. As mentioned, the large individuals might have reached a suitable size for migrating from the
nursery soft shore to subtidal habitat. From March to September 2015, the size
of major population decreased slightly to a prosomal width 40-60 mm. At the
same time, the number of individuals decreased gradually. It further indicated
some of large individuals might have migrated to sub-tidal habitats. In
December 2015 (present survey), two big individuals (prosomal width 89.27 mm
and 98.89 mm) were recorded only while it could not represent the major
population.
3.6.30As
a summary for horseshoe crab populations in
TC3 and ST, there was successful spawning of Carcinoscorpius rotundicauda from 2014 to 2015. The spawning time
should be in spring while the major spawning month might be different slightly
between two zones. There were consistent, increasing trends of population size
in these two sampling zones. For Tachypleus tridentatus, small
individuals were rarely found TC3 and ST from 2014 to 2015. It was believed no
occurrence of successful spawning. The existing individuals (that recorded
since 2012) grew to a mature size and migrated to sub-tidal habitat. Hence the
number of individuals decreased gradually. It was expected the population would
remain at low level until new round of successful spawning.
Impact of the HKLR project
3.6.31The present survey was the 13th survey 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
3.6.32In general, seagrass was found in TC3 and ST only. In TC3, seagrass Halophila ovalis was found on mud flat
between 0.5 and 1.0 m above C.D.. In ST, two seagrass species Halophila
ovalis and Zostera japonica were recorded. Both species were found on sandy substratum nearby the seaward side of mangrove vegetation at 2.0 m above C.D.
Two species were found coexisting in a long strand of seagrass bed. Photo
records were shown in Figure 3.7 of Appendix O while the complete records of
seagrass beds survey were shown in Annex III of Appendix
O.
3.6.33Table 3.2 of Appendix Osummarize the results of seagrass beds survey. In TC3, two small patches of Halophila ovaliswere found while the total seagrass
bed area was about 19.8 m2(average area 9.9 m2). The patches were in irregular shape with area 5.0-14.8
m2and low-medium
vegetation coverage 30-60%
3.6.34In ST, six patches of Halophila ovaliswere found while the total seagrass bed area was about 206.2 m2
(average area 34.4 m2). The largest patch was in irregular shape with seagrass bed
area 76.2 m2 and high vegetation coverage
80%. Two smaller patches were long strands (46.8 and 51.8 m2) with medium vegetation coverage 50-60%.
One
of them had
co-existing seagrass Zostera japonica in less vegetation
coverage.
The
rest were small patches with seagrass bed area 2.1-16.4 m2and low to medium
vegetation coverage 30-50%. For Zostera japonica, it was coexisting with Halophila ovalis in a long strand(51.8 m2) of seagrass
bed with lowervegetation coverage 30%.
3.6.35Since majority of seagrass bed was confined
in ST, the temporal change of both seagrass species were investigated in
details.
Temporal variation
of seagrass beds
3.6.36Figure 3.8 of Appendix Oshows the changes of estimated total area of seagrass beds in ST along the
sampling months. For Zostera japonica, it was not recorded in
the 1st and 2nd surveys of monitoring programme. Seasonal
recruitment of few, small patches (total seagrass area: 10 m2) was
found in March 2013 that grew within the large patch of seagrass Halophila
ovalis. Then the patch size increased and merged gradually with the warmer
climate from March to June 2013 (15 m2). However the patch size
decreased sharply and remained similar from September 2013 (4 m2) to
March 2014 (3 m2). In June 2014, the patch size increased obviously
again (41 m2) with warmer climate. Similar to previous year, the
patch size decreased again and remained similar September 2014 (2 m2)
to December 2014 (5 m2). From March to June 2015, the patch size
increased sharply again (90.0 m2). It might be due to the
disappearance of the originally dominant seagrass Halophila ovalis resulting in less competition for substratum and nutrients. From
September to December 2015, the patch size decreased and was found coexisting
with seagrass Halophila ovalis. In general, the seagrass bed of Zostera
japonica
fluctuated in patch size along the sampling months.
3.6.37For Halophila ovalis, it was recorded as 3-4 medium to large patches (area 18.9 - 251.7 m2;
vegetation coverage 50-80%) beside the mangrove vegetation at tidal level 2 m
above C.D in the September 2012 (first survey). The total seagrass bed area grew steadily from
332.3 m2 in September 2012 to 727.4 m2 in December 2013.
Flowers could be observed in the largest patch during its flowering
period in December 2013.
In March 2014, 31 small to medium patches were newly recorded (variable area
1-72 m2 per patch, vegetation coverage 40-80% per patch) in lower
tidal zone between 1.0 and 1.5 m above C.D. The total seagrass area increased
further to 1350 m2. In June 2014, these small and medium patches
grew and extended to each others. These patches were no longer distinguishable
and were covering a significant mudflat area of ST. It was generally grouped
into 4 large areas (1116 – 2443 m2) of seagrass beds characterized
of patchy distribution, variable vegetable coverage (40-80%) and smaller
leaves. The total seagrass bed area increased sharply to 7629 m2. In
September 2014, the total seagrass area declined sharply to 1111 m2.
There were only 3-4 small to large patches (6 - 253 m2) at high
tidal level and 1 patch at low tidal level (786 m2). Typhoon or strong water current was a possible cause (Fong, 1998). In September
2014, there were two tropical cyclone records in Hong Kong (7th-8th
September: no cyclone name, maximum signal number 1; 14th-17th
September: Kalmaegi maximum signal number 8SE) before the seagrass survey dated
21st September 2014. The strong water current caused by the cyclone,
Kalmaegi especially, might have given damage to the seagrass beds. In addition,
natural heat stress and grazing force were other possible causes reducing
seagrass beds area. Besides, Halophila ovalis could be found in other mud flat area surrounding
the single patch. But it was hardly distinguished into patches due to very low
coverage (10-20%) and small leaves.
3.6.38In December 2014, all the seagrass patches of
Halophila ovalis disappeared in ST. Figure 3.9 of Appendix O shows the difference of the original seagrass beds
area nearby the mangrove vegetation at high tidal level between June 2014 and
December 2014. Such rapid loss would not be seasonal phenomenon because the
seagrass beds at higher tidal level (2.0 m above C.D.) were present and normal
in December 2012 and 2013. According to Fong (1998), similar incident had
occurred in ST in the past. The original seagrass area had declined
significantly during the commencement of the construction and reclamation works
for the international airport at Chek Lap Kok in 1992. The seagrass almost disappeared
in 1995 and recovered gradually after the completion of reclamation works.
Moreover, incident of rapid loss of seagrass area was also recorded in another
intertidal mudflat in Lai Chi Wo in 1998 with unknown reason. Hence Halophila ovalis was regarded as a short-lived and r-strategy
seagrass that can colonize areas in short period but disappears quickly under
unfavourable conditions (Fong, 1998).
Unfavourable
conditions to seagrass Halophila ovalis
3.6.39Typhoon or strong water current was suggested as one unfavourable condition to Halophila ovalis (Fong, 1998). As
mentioned above, there were two tropical cyclone records in Hong Kong in
September 2014. The strong water current caused by the cyclones might have
given damage to the seagrass beds.
3.6.40Prolonged light deprivation due to turbid water would be another
unfavouable condition. Previous studies reported that Halophila ovalis had little tolerance to
light deprivation. During experimental darkness,
seagrass biomass declined rapidly after 3-6 days and seagrass died completely
after 30 days. The rapid death might be due to shortage of available
carbohydrate under limited photosynthesis or accumulation of phytotoxic end
products of anaerobic respiration (details see Longstaff et al., 1999). Hence the seagrass bed of this species was
susceptible to temporary light deprivation events such as flooding river runoff
(Longstaff and Dennison,
1999).
3.6.41In order to investigate any
deterioration of water quality (e.g. more turbid) in ST, the water quality
measurement results at two closest monitoring stations SR3 and IS5 of the
EM&A programme were obtained from the water quality monitoring team. Based
on the results from June to December 2014, the overall water quality was in
normal fluctuation except there was one exceedance of suspended solids (SS) at
both stations in September. On 10th September, 2014, the SS
concentrations measured at mid-ebb tide at stations SR3 (27.5 mg/L) and IS5
(34.5 mg/L) exceeded the Action Level (≤23.5 mg/L and 120% of upstream control station’s
reading) and Limit Level (≤34.4 mg/L and 130% of upstream control station’s
reading) respectively. The turbidity readings at SR3 and IS5 reached 24.8-25.3
NTU and 22.3-22.5 NTU respectively. The temporary turbid water should not be
caused by the runoff from upstream rivers. Because there was no rain or slight
rain from 1st to 10th September 2014 (daily total
rainfall at the Hong Kong International Airport: 0-2.1 mm; extracted from the
climatological data of Hong Kong Observatory). The effect of upstream runoff on
water quality should be neglectable in that period. Moreover the exceedance of
water quality was considered unlikely to be related to the contract works of
HKLR according to the ‘Notifications of Environmental Quality Limits
Exceedances’ provided by the respective environmental team. The respective
construction of seawall and stone column works, which possibly caused turbid
water, were carried out within silt curtain as recommended in the EIA report.
Moreover there was no leakage of turbid water, abnormity or malpractice
recorded during water sampling. In general, the exceedance of suspended solids
concentration was considered to be attributed to other external factors, rather
than the contract works.
3.6.42Based on the weather condition
and water quality results in ST, the co-occurrence of cyclone hit and turbid
waters in September 2014 might have combined the adverse effects on Halophila ovalisthat leaded to disappearance of this short-lived and r-strategy seagrass species. Fortunately
Halophila ovalis was a fast-growing
species (Vermaat et al., 1995). Previous studies showed that the
seagrass bed could be recovered to the original sizes in 2 months through
vegetative propagation after experimental clearance (Supanwanid, 1996).
Moreover it was reported to recover rapidly in less than 20 days after dugong
herbivory (Nakaoka and Aioi, 1999). As mentioned, the disappeared seagrass in
ST in 1995 could recover gradually after the completion of reclamation works for
international airport (Fong, 1998). The seagrass beds of Halophila ovalis might recolonize the
mudflat of ST through seed reproduction as long as there was no unfavourable
condition in the coming months.
Recolonization of
seagrass beds
3.6.43Figure 3.9 of Appendix Oshows the changes of
seagrass bed area at ST. From March to June 2015, 2-3 small
patches of Halophila
ovalis were newly found coinhabiting with another
seagrass speciesZostera japonica. But its total
patch area was still very low relative to the previous records. The
recolonization rate was low while cold weather and insufficient sunlight were
possible factors between December 2014 and March 2015. Moreover, it would need
to compete with more abundant seagrass Zostera
japonica for substratum and nutrient. Since Zostera japonica had extended and had
covered the original seagrass bed of Halophila ovalis at certain degree. From June to December 2015, the total seagrass area of Halophila ovalis had increased rapidly
from 6.8 m2 to 206.21 m2. It had recolonized its original
patch locations and covered Zostera japonica.
Hence it was expected that the seagrass bed of Halophila ovalis would increase continually in the following
months.
Impact of the HKLR project
3.6.44The present survey was the 13th
survey of the EM&A programme during the construction period. According to
the results of present survey,there was recolonization of both seagrass species Halophila ovalis and Zostera japonica in
ST. The seagrass patches were believed in recovery. Hence the negative
impact of HKLR project on the seagrass was not significant. In case, adverse phenomenon (e.g. reduction of seagrass patch size, abnormal change of leave colour) is observed
again, it would be reported as soon as possible.
Intertidal
Soft Shore Communities
3.6.45Table 3.3 and Figure 3.10 of Appendix O show the types of substratum along the horizontal transect at every
tidal level in every sampling zone. The relative distribution of different substrata was
estimated by categorizing the substratum types (Gravels & Boulders / Sands /
Soft mud) of the ten random quadrats along the horizontal transect.The distribution of substratum types varied
among tidal levels and sampling
zones:
·In TC1, high percentage of
‘Gravels and Boulders’ (80-100%) was recorded at all tidal levels while the
rest was ‘Sands’ (20% at high and low tidal levels).
·In TC2, high percentage of
‘Sands’ (60-80%) was recorded at high and mid tidal levels followed by ‘Soft
mud’ (20-30%). At low tidal level, high percentage of ‘Soft mud’ (80%) was
recorded followed by ‘Sands’ (20%).
·In TC3, the substratum type was
clearly different between high-mid tidal level and low tidal level. ‘Sands’
(50-80%) and ‘Soft mud’ (20-40%) were the main substratum types at high and mid
tidal levels. ‘Gravels and Boulders’ (100%) was the only substratum type at low
tidal level.
·In ST, the substratum type was
clearly different between high-mid tidal level and low tidal level. ‘Gravels
and Boulders’ (100%) was the only substratum type at high and mid tidal levels.
At low tidal level, higher percentage of ‘Gravels and Boulders’ (50%) was
recorded followed by ‘Sands’ (30%) and ‘Soft mud’ (20%).
3.6.46There was neither consistent vertical nor horizontal zonation pattern of
substratum type in all sampling zones. Such heterogeneous variation should be caused by different hydrology (e.g. wave in
different direction and intensity) received by the four sampling zones.
3.6.47Table 3.4 of Appendix O lists the total abundance, density and number of taxon of every phylum in
this survey. A total
of 10726 individuals
were recorded. Mollusca was significantly the most abundant phylum (total
individuals 10409, density 347 ind. m-2, relative
abundance 97.0%).
The second abundant phylum
was Arthropoda (201 ind.,
7 ind. m-2, 1.9%). The less abundant phyla wereAnnelida
(37 ind., 1 ind. m-2, 0.3%), Sipuncula (33 ind., 1 ind. m-2, 0.3%) and Echiura (24 ind., 1 ind. m-2,
0.2%).Relatively
other phyla were very low in abundances (density £1 ind. m-2, relative
abundance £0.1%). Moreover, the most diverse phylum wasMollusca (37 taxa) followed by Arthropoda (11 taxa) and Annelida (7 taxa). There was 1-2
taxa recorded only for other phyla. The taxonomic
resolution and complete list of collected specimens are shown in Annex IV and V of Appendix O.
3.6.48Table 3.5of Appendix O shows the
number of individual, relative abundance and density of each phylum in every sampling zone. The total abundance (1443-3660 ind.) varied among the four sampling
zones while the phyla
distributionswere similar. In general, Molluscawas the most dominant phylum (no. of
individuals: 1367-3602
ind.; relative abundance
94.7-98.4%; density 182-480 ind. m-2). Other phyla were significantly lower in number of individuals. Arthropoda was the second abundant
phylum (26-73
ind.;0.7-3.7%; 3-10 ind.
m-2). Echiura was the third abundant
phylum (17 ind.; 0.5%; 2 ind. m-2) in
TC1. Annelida was the third and forth abundant phylum (13-16 ind.; 0.4-1.1%; 2 ind. m-2) in TC2 and TC3
respectively. Sipuncula was the third abundant phylum (16 ind.; 0.5%; 2 ind. m-2)
in TC3. Cnidaria (sea anemone) was the third abundant phylum (13 ind.; 0.5%; 2 ind. m-2) in ST.Relatively other phyla were low in abundance among the four sampling zones (≤ 0.4%).
Dominant species in every sampling zone
3.6.49Table 3.6of Appendix O lists the
abundant species (relative abundance >10%) in every sampling zone. In TC1, gastropod Batillaria multiformis was the
most abundant species of high density (265 ind. m-2, relative
abundance 56%) followed by gastropods Cerithidea cingulata(79 ind. m-2, 17%) and Cerithidea
djadjariensis(68 ind. m-2, 14%)at high tidal level (major substratum: ‘Gravels
and Boulders’). At mid and low tidal levels (major substratum: ‘Gravels and
Boulders’), the abundant species were gastropods Batillaria
multiformis (121-170 ind. m-2, 23-37%), Monodonta labio (136-156 ind. m-2, 29-30%) and rock oyster Saccostrea cucullata
(76-155 ind. m-2, 16-29%, attached on boulders) at moderate densities.
3.6.50At TC2, gastropod Cerithidea djadjariensis(122 ind. m-2, 53%) was the most abundant
at moderate density followed by gastropod Cerithidea
cingulata (70 ind. m-2, 20%) and rock oyster Saccostrea cucullata (56 ind. m-2, 16%)at high tidal level (major substratum: ‘Sands’).Relative
to high tidal level, the density of every species was much lower and similar at
mid and low tidal levels. No species was clearly dominant. At mid tidal level
(major substratum: ‘Sands’), rock oyster Saccostrea cucullata (54 ind. m-2, 35%),gastropods
Cerithidea djadjariensis(30 ind. m-2,
19%), Batillaria zonalis (26 ind. m-2, 16%) andCerithidea cingulata (18 ind. m-2, 11%) werecommonly occurring at low densities. At low
tidal level (major substratum: ‘Soft mud’), rock oyster Saccostrea
cucullata (28 ind. m-2, 44%),barnacle Balanus amphitrite (9 ind. m-2, 14%) and
gastropod Lunella coronata(7 ind. m-2, 11%) werecommonly
occurring at low density.
3.6.51At TC3, the abundant
species were similar in density at high and mid tidal levels (major substratum: ‘Sands’). No
species was clearly dominant. There were gastropods Cerithidea djadjariensis (96-99 ind. m-2, 35-37%), Cerithidea cingulata(72 ind. m-2, 25-28%), Batillaria
multiformis (92 ind. m-2, 32% at high tidal level) and rock oyster Saccostrea cucullata (32 ind. m-2, 12% at
mid tidal level) at low-medium densities. At low tidal level (major substratum: ‘Gravels and Boulders’), rock oyster Saccostrea cucullata (304 ind. m-2, 47%) was clearly abundant followed by gastropod Monodonta
labio (180 ind. m-2, 28%)at moderate density.
3.6.52At ST, gastropod Monodonta labio(103-136 ind. m-2, 23-32%),rock oyster Saccostrea
cucullata (61-150 ind. m-2, 14-34%) and
gastropod Lunella coronata(49-69 ind. m-2, 12-15%) were abundant at low-medium densities at high and mid tidal levels
(major substratum: ‘Gravels and Boulders’). Gastropod Batillaria multiformis (111 ind. m-2, 26%) was
also at medium density at high tidal level. At low tidal level (major
substratum: ‘Gravels and Boulders’), gastropod Lunella coronata(58 ind. m-2, 30%) and rock oyster Saccostrea
cucullata (54 ind. m-2, 28%) were relatively abundant at low densities.
3.6.53In general, there was no consistent zonation pattern of species distribution
observed across all sampling zones and tidal levels. The species distribution should be determined by the type of substratum primarily. In general, gastropods Batillaria multiformis (total number of individuals: 2057 ind., relative abundance 19.2%), Cerithidea djadjariensis (1155 ind., 10.8%) and Cerithidea cingulata (834 ind., 7.8%) were the most commonly
occurring species on sandy and soft mud substrata. Rock oyster Saccostrea cucullata(2458 ind., 22.9%), gastropods Monodonta labio
(1946 ind., 18.1%) and Lunella coronata (674 ind., 6.3%) were commonly occurring species inhabiting
gravel and boulders substratum.
Biodiversity and abundance of soft shore
communities
3.6.54Table 3.7of Appendix Oshows the mean values of
species number, density, biodiversity index H’and species evennessJof soft shore communities at every tidal level and in every sampling zone. Among the sampling zones, the
mean species number (11 spp. 0.25 m-2) and mean H’ (1.6) in ST were slightly higher than other sampling zones (mean
species number: 7-9 spp. 0.25 m-2, H’ 1.2-1.4). The mean densities were quite variable among sites.
The mean density of TC1 was highest (488 ind. m-2) followed by TC3
(395 ind. m-2) and ST (355 ind. m-2). TC2 was lowest in
mean density (192 ind. m-2). However mean J showed no clear difference among sampling zones (0.6-0.8).
3.6.55Across the tidal levels, there was
no consistent difference of the mean number of species, H’ and J in all sampling
zones. For the mean density, a general decreasing trend was observed from high
to low tidal level at TC2 and ST. But a general increasing trend was observed
from low to high tidal level at TC1 and TC3. As mentioned, the variation of
mean density should be determined by the type of
substratum primarily.
3.6.56Figures 3.11 to 3.14 of Appendix O show the temporal changes of mean number of species, mean density, H’ andJat every tidal level and in every sampling zone along the sampling months.
Overall no consistent temporal change of any biological parameters was
observed. All the parameters were under slight and natural fluctuation with the
seasonal variation.
Impact of the HKLR project
3.6.57The present survey was the 13th survey 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. In case, abnormal phenomenon (e.g. large
reduction of fauna densities and species number) is observed, it would be
reported as soon as possible.
3.7Solid and Liquid Waste Management Status
3.7.1The 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.
3.7.2The summary of waste flow table is detailed in Appendix K.
3.7.3The 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 Practice on
the Packaging, Labelling and Storage of Chemical Wastes.
3.8Environmental Licenses and Permits
3.8.1The valid environmental licenses and permits
during the reporting period are summarized in Appendix L.
4.1.1The detailed air quality, noise, water quality and dolphin exceedances
are provided in Appendix M. Also, the summaries of the
environmental exceedances are presented as follows:
Air Quality
4.1.2Three Action Level exceedances of
1-hr TSP level at AMS5 and two Action Level exceedances of 1-hr TSP level at
AMS6 were recorded during the reporting period. There were no
Action and Limit Level exceedances of 24-hour TSP were recorded at AMS5 and
AMS6 during the reporting period.
Noise
4.1.3There were no Action/Limit Level exceedances for noise during daytime on
normal weekdays of the
reporting period.
Water Quality
4.1.1For marine water quality monitoring, a Limit Level
exceedance of turbidity level was recorded at stations IS8 and SR4 during
mid-flood tide on 5 February 2016 respectively. An Action Level exceedance of
suspended solids level was recorded at station IS8 and a Limit Level exceedance
of suspended solid was recorded at station SR4 during mid-flood tide on 5
February 2016.
4.1.2The construction activities were carried out
within silt curtain as recommended in the EIA Report. There were no
specific activities recorded during the monitoring period that would cause any
significant impacts on the monitoring results. The exceedance of suspended
solid level was considered
to be attributed to other external factors, rather than the contract works.
Therefore, the exceedance was
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.
Table 4.1Summary
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
--
--
--
--
--
--
--
--
0
0
Limit Level
--
--
--
--
--
--
--
--
0
0
IS(Mf)6
Action Level
--
--
--
--
--
--
--
--
0
0
Limit Level
--
--
--
--
--
--
--
--
0
0
IS7
Action Level
--
--
--
--
--
--
--
--
0
0
Limit Level
--
--
--
--
--
--
--
--
0
0
IS8
Action Level
--
--
--
--
--
--
--
5
Feb 2016
0
1
Limit Level
--
--
--
--
--
5
Feb 2016
--
--
0
1
IS(Mf)9
Action Level
--
--
--
--
--
--
--
--
0
0
Limit Level
--
--
--
--
--
--
--
--
0
0
IS10
Action Level
--
--
--
--
--
--
--
--
0
0
Limit Level
--
--
--
--
--
--
--
--
0
0
SR3
Action Level
--
--
--
--
--
--
--
--
0
0
Limit Level
--
--
--
--
--
--
--
--
0
0
SR4
Action Level
--
--
--
--
--
--
--
--
0
0
Limit Level
--
--
--
--
--
5
Feb 2016
--
5
Feb 2016
0
2
SR5
Action Level
--
--
--
--
--
--
--
--
0
0
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
0
1
1**
Limit
0
0
0
0
0
2
0
1
3**
Notes:
S: Surface;
M: Mid-depth;
**The
total exceedances.
Dolphin
4.1.3There was one Limit Level exceedance of dolphin
monitoring for the quarterly monitoring data (between December 2015 – February
2016). According to the contractor’s information, the marine activities undertaken
for HKLR03 during the quarter of December 2015 to February 2016 included
reclamation, construction of surcharge, removal of surcharge materials,
construction of seawall, temporary drainage diversion, ground investigation and
maintenance of silt curtain.
4.1.4There
is no evidence showing the current LL non-compliance directly related to the
construction works of HKLR03 (where the amounts of working vessels for HKLR03
have been decreasing), although the generally increased amount of vessel
traffic in NEL 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 – Sham Shui Kok Anchorage (near
Brothers Island) as far as practicable.
4.1.5All dolphin protective measures are fully and
properly implemented in accordance with the EM&A Manual. According to the
Marine Travel Route Plan, the travelling speed of vessels must not exceed 5
knots when crossing the edge of the proposed marine park. The Contractor will
continue to provide training for skippers to ensure that their working vessels
travel from source to destination to minimize impacts on Chinese White Dolphin
and avoid anchoring at Marine Department’s designated anchorage site - Sham
Shui Kok Anchorage (near Brothers Island) as far as practicable. Also, it is
recommended to complete the marine works of the Contract as soon as possible so
as to reduce the overall duration of impacts and allow the dolphins population
to recover as early as possible.
4.2Summary of Environmental Complaint, Notification of
Summons and Successful Prosecution
4.2.1There were no complaints received during the
reporting period. The details of cumulative statistics
of Environmental Complaints are provided in Appendix
N.
4.2.2No notification of
summons and prosecution was received during the reporting period.
4.2.3Statistics on
notifications of summons and successful prosecutions are summarized in Appendix M.
5.1.1According to the environmental site inspections undertaken during
the reporting period, the following recommendations were provided:
§The Contractor was reminded to
water the haul road to prevent fugitive dust emissions at N26.
§The Contractor was reminded to
close mechanical cover of the dump truck when transporting dusty materials S16.
§The Contractor was reminded to
provide water spay to dusty stockpile to avoid fugitive dust emission at N26.
§The Contractor was reminded to
cover the cement bags entirely at N1and S15.
§The Contractor was reminded to
provide a proper enclosure for the grouting station at HAT.
§The Contractor was reminded to
clean up the silt/dirt/dusty materials from the roadside near S7.
§The Contractor was reminded to
clear the sand from roadside of S25.
§The Contractor was reminded to
place the noise barriers properly at S16.
§The Contractor was reminded to
provide wheel washing for vehicles before leaving the site at N26.
§The Contractor was reminded to
provide mitigation measures to avoid falling off of objects into the storm
drain at N26.
§The Contractor was reminded to
provide sand bags around the manhole to prevent discharge of silty surface
runoff into the drain at HAT.
§The Contractor was reminded to
turn on the mixer of wastewater treatment plant to ensure the treatment
efficiency at N26.
§The Contractor was reminded to
remove the construction materials near the entrance of wheel washing bay at
S23.
§The Contractor was reminded to
remove the accumulated sediment inside the wastewater treatment facility regularly
at S23.
§The Contractor was reminded to
remove the blockage inside the wheel washing facility at N4.
§The Contractor was reminded to
maintain a bund /provide proper protection along the seafront to avoid dropping
silt or debris into the sea at S7 and S11.
§The Contractor was reminded to
provide proper treatment for the wastewater generated from the construction
site at S11.
§The Contractor was reminded to
provide proper protection along the deck of the barging point at S7.
§The Contractor was reminded to
align, inspect and maintain the silt curtains properly at Portion X and near
S7.
§The Contractor was reminded to
provide a proper connection for the wastewater treatment facility at PR9 and
N4.
§The Contractor was reminded to
treat the wastewater properly before discharging at discharge point PR10 at S9
and S23.
§The Contractor was reminded to
clean up the silt/dirt on the footpath near S7.
§The Contractor was reminded to
remove the abandoned tire at S7.
§The Contractor was reminded to
remove the rubbish near the seafront at S7.
§The Contractor was reminded to
dispose of waste regularly at S7, S11, S16, S19, S25, HMA, N4, PR9 and A2
bridge at N20 regularly.
§The Contractor was reminded to
provide proper segregation and collection of waste at N1.
§The Contractor was reminded to
remove the empty oil drum at HMA site.
§The Contractor was reminded to
provide drip trays for the chemicals at HMA, N1, S8, S11, S15 and S23.
§The Contractor was reminded to
provide a drip tray for the oil drums at S7, S11 and N20.
§The Contractor was reminded to
provide proper labelling of chemicals at N1 and N26.
§The Contractor was reminded to
clear stagnant water inside the steel beam at N4 and S11.
§The Contractor was reminded to
remove stagnant water inside the drip tray of A2 bridge at N20 and N4 to avoid
mosquito breeding.
§The Contractor was reminded to
clear the stagnant water on the ground at S8, S15, S23 and N1.
§The Contractor was reminded to
place additional sand bags along the boundary of dusty material at N1.
§The Contractor was reminded to
replace the broken sand bags at N20.
§The Contractor was reminded to
dispose of concrete waste at N1.
§The Contractor was reminded to
provide a wheel washing facility at the exit of S25.
§The Contractor was reminded to
provide clear indication of the pipe to show the source of effluent discharge
at S11.
5.2Recommendations
5.2.1The 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.
5.2.2The 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.
5.3.1The construction phase and
EM&A programme of the Contract commenced on 17 October 2012. This is the fourteenth Quarterly EM&A Report which summarizes the monitoring results and audit findings of the EM&A
programme during the reporting period from 1 December 2015to 29 February2016.
Air Quality
5.3.2Three Action Level exceedances 1-hr TSP level at AMS5 and two Action Level
exceedance of 1-hr TSP level at AMS6 were recorded during the reporting period.
Noise
5.3.3There were no Action/Limit Level exceedances for noise during daytime on
normal weekdays of the reporting period.
Water Quality
5.3.4For marine water quality monitoring, a Limit Level
exceedance of turbidity level was recorded at stations IS8 and SR4 during
mid-flood tide on 5 February 2016 respectively. An Action Level exceedance of
suspended solids level was recorded at station IS8 and a Limit Level exceedance
of suspended solid was recorded at station SR4 during mid-flood tide on 5
February 2016. No exceedance of Action
Level for turbidity level was recorded. No exceedances of Action and Limit Level for
dissolved oxygen level were recorded.
Dolphin
5.3.5There was a Limit Level exceedance of dolphin monitoring for the
quarterly monitoring data (between December 2015 – February 2016).
5.3.6During this quarter of dolphin
monitoring, no adverse impact from the activities of this construction project
on Chinese White Dolphins was noticeable from general observations.
5.3.7Although 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 since 2012, and many individuals have shifted away from the
important habitat around the Brothers Islands.
5.3.8It is 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 the situation.
Mudflat
-Sedimentation Rate
5.3.9This measurement result was generally and relatively higher than the baseline
measurement at S1, S2, S3 and S4. The mudflat level is continuously increased.
Mudflat - Ecology
5.3.10The December 2015 survey was
the thirteenth survey of the EM&A programme during the construction period.
Based on the results, impacts of the HKLR project could not be detected on
horseshoe crabs, seagrass and intertidal soft shore community.
Environmental Site Inspection and Audit
5.3.11Environmental
site inspection was carried out on 2, 9, 17,
23, 29 December 2015;6, 13, 20, 29 January 2016; and 3, 12, 15, 26 February 2016. Recommendations on remedial actions were
given to the Contractors for the deficiencies identified during the site
inspections.
5.3.12There were no complaints received
in relation to the environmental impacts during the reporting period.
5.3.13No notification of summons and
prosecution was received during the reporting period.