The Hong Kong-Zhuhai-Macao
Bridge (HZMB) Hong Kong Link Road (HKLR) serves to connect the HZMB Main Bridge
at the Hong Kong Special Administrative Region (HKSAR) Boundary and the HZMB
Hong Kong Boundary Crossing Facilities (HKBCF) located at the north eastern waters
of the Hong Kong International Airport (HKIA).
The HKLR project has been
separated into two contracts. They are Contract No. HY/2011/03 Hong
Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between Scenic Hill and
Hong Kong Boundary Crossing Facilities (hereafter referred to as the Contract)
and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link
Road-Section between HKSAR Boundary and Scenic Hill.
China State Construction
Engineering (Hong Kong) Ltd. was awarded by Highways Department as the
Contractor to undertake the construction works of Contract No. HY/2011/03.The main works of the Contract include
land tunnel at Scenic Hill, tunnel underneath Airport Road and Airport Express
Line, reclamation and tunnel to the east coast of the Airport Island, at-grade
road connecting to the HKBCF and highway works of the HKBCF within the Airport
Island and in the vicinity of the HKLR reclamation.The Contract is part of the HKLR Project
and HKBCF Project, these projects are considered to be ¡§Designated Projects¡¨,
under Schedule 2 of the Environmental Impact Assessment (EIA) Ordinance (Cap
499) and Environmental Impact Assessment (EIA) Reports (Register No.
AEIAR-144/2009 and AEIAR-145/2009) were prepared for the Project.The current Environmental Permit (EP) EP-352/2009/D
for HKLR and EP-353/2009/J for HKBCF were issued on 22 December 2014 and 25 February
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 forty-second Monthly 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 to 31 March 2016.
Environmental
Monitoring and Audit Progress
The monthly EM&A
programme was undertaken in accordance with the Updated EM&A Manual for
HKLR (Version 1.0).A summary of
the monitoring activities during this reporting month is listed below:
1-hr TSP Monitoring
1, 7, 11, 17 23 and 29 March 2016
24-hr TSP Monitoring
4, 10, 16, 21,
24 and 30 March 2016
Noise Monitoring
1, 7, 17, 23 and 29 March 2016
Water Quality Monitoring
2, 4, 7, 9, 11, 14, 16, 18, 21, 23, 25, 28 and 30 March 2016
Chinese White Dolphin
Monitoring
7, 11, 22 and 23 March 2016
Mudflat Monitoring
(Sedimentation Rate)
9 March 2016
Mudflat Monitoring
(Ecology)
8, 12, 13, 20, 22 and 26 March 2016
Site Inspection
3, 9, 16, 23 and 29 March
2016
Due to boat availability, the dolphin monitoring schedule was rescheduled
from 14 March 2016 to 11 March 2016.
Due to weather condition, the dolphin monitoring schedule was
rescheduled from 21 March 2016 to 22 March 2016.
Due to change of weather condition, mudflat monitoring (ecology) was
rescheduled from 6 March 2016 to 8 March and from 23 March 2016 to 26 March
2016.
Breaches of Action and Limit Levels
A summary of environmental
exceedances for this reporting month is as follows:
Environmental
Monitoring
Parameters
Action
Level (AL)
Limit
Level (LL)
Air Quality
1-hr TSP
0
0
24-hr TSP
0
0
Noise
Leq (30 min)
0
0
Water Quality
Suspended solids level (SS)
0
0
Turbidity level
0
0
Dissolved oxygen level (DO)
0
0
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 month.
Reporting
Changes
This report has been developed
in compliance with the reporting requirements for the subsequent 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.
Future Key
Issues
The future key issues
include potential noise, air quality, water quality and ecological impacts and
waste management arising from the following construction activities to be
undertaken in the upcoming month:
Dismantling/trimming
of Temporary 40mm Stone Platform for Construction of Seawall at Portion X;
Filling Works behind
Stone Platform at Portion X;
Construction of
Seawall at Portion X;
Loading and Unloading
Filling Material at Portion X;
Pipe Piling at Portion
X;
Excavation and Lateral
Support Works at Scenic Hill Tunnel (Cut & Cover Tunnel) at Portion X;
Construction of Tunnel
Box Structure at Scenic Hill Tunnel (Cut & Cover Tunnel) at Portion X;
Pipe piling works for
Scenic Hill Tunnel (Cut & Cover Tunnel) at Portion X and Y;
Excavation for diversion of culvert PR10 at Portion X;
Excavation Works for
HKBCF to Airport Tunnel at Portion X;
Sheet Piling Works for
HKBCF to Airport Tunnel East (Cut & Cover Tunnel) at Portion X;
¡PWorks for Diversion of Airport Road;
Utilities Detection at
Airport Road / Airport Express Line/ East Coast Road;
Establishment of Site
Access at Airport Road / Airport Express Line/East Coast Road;
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 Environmental
Impact Assessment (EIA) Reports (Register No. AEIAR-144/2009 and
AEIAR-145/2009) were prepared for the Project.The current Environmental Permit (EP)
EP-352/2009/D for HKLR and EP-353/2009/J for HKBCF were issued on 22 December
2014 and 25 February 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. The works areas are shown in Appendix O.
1.1.4The Contract includes the following key aspects:
¡PNew reclamation along
the east coast of the approximately 23 hectares.
¡PTunnel of Scenic Hill
(Tunnel SHT) from Scenic Hill to the new reclamation, of approximately 1km in
length with three (3) lanes for the east bound carriageway heading to the HKBCF
and four (4) lanes for the westbound carriageway heading to the HZMB Main
Bridge.
¡PAn abutment of the
viaduct portion of the HKLR at the west portal of Tunnel SHT and associated
road works at the west portal of Tunnel SHT.
¡PAn at grade road on
the new reclamation along the east coast of the HKIA to connect with the HKBCF,
of approximately 1.6 km along dual 3-lane carriageway with hard shoulder for
each bound.
¡PRoad links between
the HKBCF and the HKIA including new roads and the modification of existing
roads at the HKIA, involving viaducts, at grade roads and a Tunnel HAT.
¡PA highway operation
and maintenance area (HMA) located on the new reclamation, south of the Dragonair Headquarters Building, including the construction
of buildings, connection roads and other associated facilities.
¡PAssociated civil,
structural, building, geotechnical, marine, environmental protection,
landscaping, drainage and sewerage, tunnel and highway electrical and
mechanical works, together with the installation of street lightings, traffic
aids and sign gantries, water mains and fire hydrants, provision of facilities
for installation of traffic control and surveillance system (TCSS), reprovisioning works of affected existing facilities,
implementation of transplanting, compensatory planting and protection of
existing trees, and implementation of an environmental monitoring and audit
(EM&A) program.
1.1.6BMT Asia Pacific Limited has been
appointed by the Contractor to implement the EM&A programme
for the Contract in accordance with the Updated EM&A Manual for HKLR
(Version 1.0) for HKLR and will be providing environmental team services to the
Contract. Ramboll Environ Hong Kong Ltd. was employed by HyD as the Independent
Environmental Checker (IEC) and Environmental Project Office (ENPO) for the
Project. The project organization with regard to the
environmental works is as follows.
1.2.1The project
organization structure and lines of communication with respect to the on-site
environmental management structure is shown in Appendix A.The key
personnel contact names and numbers are summarized in Table 1.1.
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
Jet Grouting works for HKBCF to Airport
Tunnel East (Cut & Cover Tunnel
Portion X
2Air Quality Monitoring
2.1Monitoring
Requirements
2.1.1In accordance with
the Contract Specific EM&A Manual, baseline 1-hour and 24-hour TSP levels
at two air quality monitoring stations were established. Impact 1-hour TSP monitoring was
conducted for at least three times every 6 days, while impact 24-hour TSP
monitoring was carried out for at least once every 6 days. The Action and Limit
Level for 1-hr TSP and 24-hr TSP are provided in Table 2.1 and Table 2.2,
respectively.
2.2.124-hour TSP air
quality monitoring was performed using High Volume Sampler (HVS) located at
each designated monitoring station. The HVS meets all the requirements of the Contract
Specific EM&A Manual. Portable
direct reading dust meters were used to carry out the 1-hour TSP
monitoring.Brand and model of the
equipment is given in Table 2.3.
Table 2.3Air
Quality Monitoring Equipment
Equipment
Brand and Model
Portable direct reading dust meter (1-hour
TSP)
Sibata Digital Dust Monitor (Model No. LD-3B)
High Volume Sampler
(24-hour TSP)
Tisch Environmental Mass Flow Controlled Total
Suspended Particulate (TSP) High Volume Air Sampler (Model No. TE-5170)
(a)The HVS was installed in the vicinity of the air sensitive receivers.
The following criteria were considered in the installation of the HVS.
(i)A horizontal platform with appropriate support to secure the sampler
against gusty wind was provided.
(ii)The distance between the HVS and any obstacles, such as buildings, was
at least twice the height that the obstacle protrudes above the HVS.
(iii)A minimum of 2 meters separation from walls, parapets and penthouse for
rooftop sampler was provided.
(iv)No furnace or incinerator flues are nearby.
(v)Airflow around the sampler was unrestricted.
(vi)Permission was obtained to set up the samplers and access to the monitoring
stations.
(vii)A secured supply of electricity was obtained to operate the samplers.
(viii)The sampler was located more than 20 meters from any dripline.
(ix)Any wire fence and gate, required to protect the sampler, did not
obstruct the monitoring process.
(x)Flow control accuracy was kept within ¡Ó2.5% deviation over 24-hour
sampling period.
(b)Preparation of Filter Papers
(i)Glass fibre filters, G810 were labelled and sufficient filters that were
clean and without pinholes were selected.
(ii)All filters were equilibrated in the conditioning environment for 24
hours before weighing. The conditioning environment temperature was around 25 ¢XC and not variable by more than ¡Ó3 ¢XC; the relative humidity (RH) was < 50%
and not variable by more than ¡Ó5%. A
convenient working RH was 40%.
(iii)All filter papers were prepared and analysed by ALS Technichem
(HK) Pty Ltd., which is a HOKLAS accredited laboratory and has comprehensive
quality assurance and quality control programmes.
(c)Field Monitoring
(i)The power supply was checked to ensure the HVS works properly.
(ii)The filter holder and the area surrounding the filter were cleaned.
(iii)The filter holder was removed by loosening the four bolts and a new
filter, with stamped number upward, on a supporting screen was aligned
carefully.
(iv)The filter was properly aligned on the screen so that the gasket formed
an airtight seal on the outer edges of the filter.
(v)The swing bolts were fastened to hold the filter holder down to the
frame.The pressure applied was
sufficient to avoid air leakage at the edges.
(vi)Then the shelter lid was closed and was secured with the aluminium
strip.
(vii)The HVS was warmed-up for about 5 minutes to establish run-temperature
conditions.
(viii)A new flow rate record sheet was set into the flow recorder.
(ix)On site temperature and atmospheric pressure readings were taken and the
flow rate of the HVS was checked and adjusted at around 1.1 m3/min,
and complied with the range specified in the Updated EM&A Manual for HKLR
(Version 1.0) (i.e. 0.6-1.7 m3/min).
(x)The programmable digital timer was set for a sampling period of 24 hours,
and the starting time, weather condition and the filter number were recorded.
(xi)The initial elapsed time was recorded.
(xii)At the end of sampling, on site temperature and atmospheric pressure
readings were taken and the final flow rate of the HVS was checked and
recorded.
(xiii)The final elapsed time was recorded.
(xiv)The sampled filter was removed carefully and folded in half length so that only surfaces with collected
particulate matter were in contact.
(xv)It was then placed in a clean plastic envelope and sealed.
(xvi)All monitoring information was recorded on a standard data sheet.
(xvii)Filters were then sent to ALS Technichem (HK)
Pty Ltd. for analysis.
(d)Maintenance and Calibration
(i)The HVS and its accessories were maintained in good working condition,
such as replacing motor brushes routinely and checking electrical wiring to ensure
a continuous power supply.
(ii)5-point calibration of the HVS was conducted using TE-5025A Calibration Kit prior to the
commencement of baseline monitoring. Bi-monthly 5-point calibration of the HVS
will be carried out during impact monitoring.
(iii)Calibration certificate of the HVSs are provided in Appendix C.
2.5.21-hour TSP
Monitoring
(a)Measuring Procedures
The measuring procedures of
the 1-hour dust meter were in accordance with the Manufacturer¡¦s Instruction
Manual as follows:-
(i)Turn the power on.
(ii)Close the air collecting opening cover.
(iii)Push the ¡§TIME SETTING¡¨ switch to [BG].
(iv)Push ¡§START/STOP¡¨ switch to perform background measurement for 6
seconds.
(v)Turn the knob at SENSI ADJ position to insert the light scattering
plate.
(vi)Leave the equipment for 1 minute upon ¡§SPAN CHECK¡¨ is indicated in the
display.
(vii)Push ¡§START/STOP¡¨ switch to perform automatic sensitivity adjustment.
This measurement takes 1 minute.
(viii)Pull out the knob and return it to MEASURE position.
(ix)Push the ¡§TIME SETTING¡¨ switch the time set in the display to 3 hours.
(x)Lower down the air collection opening cover.
(xi)Push ¡§START/STOP¡¨ switch to start measurement.
(b)Maintenance and Calibration
(i)The
1-hour TSP meter was calibrated at 1-year intervals against a Tisch Environmental Mass Flow Controlled Total Suspended
Particulate (TSP) High Volume Air Sampler. Calibration certificates of the
Laser Dust Monitors are provided in Appendix C.
2.6.1The schedule for air quality monitoring March 2016 is
provided in Appendix D.
2.7Monitoring
Results
2.7.1The monitoring results for 1-hour TSP and 24-hour TSP
are summarized in Tables 2.6 and 2.7 respectively. Detailed impact air
quality monitoring results and relevant graphical plots are presented in Appendix E.
Table 2.6Summary
of 1-hour TSP Monitoring Results During the Reporting Month
Monitoring Station
Average (mg/m3)
Range (mg/m3)
Action Level (mg/m3)
Limit Level (mg/m3)
AMS5
169
117 - 232
352
500
AMS6
160
107 - 285
360
500
Table 2.7 Summary
of 24-hour
TSP Monitoring Results During the Reporting Month
Monitoring Station
Average (mg/m3)
Range (mg/m3)
Action Level(mg/m3)
Limit Level (mg/m3)
AMS5
48
19 - 112
164
260
AMS6
61
29 - 143
173
260
2.7.2No Action and Limit Level exceedances of 1-hr TSP
and 24-hr TSP were recorded at AMS5 and AMS6 during the reporting month.
2.7.3The event action plan
is annexed in Appendix F.
2.7.4The
wind data obtained from the on-site weather station
during the reporting month is
shown in Appendix G.
3.1.1In accordance with
the Contract Specific EM&A Manual, impact noise monitoring was conducted
for at least once per week during the construction phase of the Project. The
Action and Limit level of the noise monitoring is provided in Table 3.1.
Table
3.1Action
and Limit Levels for Noise during Construction Period
Monitoring Station
Time Period
Action Level
Limit Level
NMS5 ¡V Ma Wan Chung
Village (Ma Wan Chung Resident Association) (Tung Chung)
0700-1900 hours on normal
weekdays
When one documented
complaint is received
75 dB(A)
3.2Monitoring
Equipment
3.2.1Noise monitoring was
performed using sound level meters at each designated monitoring station.The sound level meters deployed comply
with the International Electrotechnical Commission
Publications (IEC) 651:1979 (Type 1) and 804:1985 (Type 1) specifications.Acoustic calibrator was deployed to
check the sound level meters at a known sound pressure level.Brand and model of the equipment are
given in Table 3.2.
Table 3.2
Noise
Monitoring Equipment
Equipment
Brand and Model
Integrated Sound Level
Meter
B&K 2238
Acoustic Calibrator
B&K 4231
3.3Monitoring
Locations
3.3.1Monitoring location NMS5 was set up at the
proposed locations in accordance with Contract Specific EM&A Manual.
3.3.2Figure
2.1 shows the locations
of monitoring stations. Table 3.3 describes the details of the monitoring
stations.
Table
3.3Locations
of Impact Noise Monitoring Stations
Monitoring Station
Location
NMS5
Ma Wan Chung Village (Ma
Wan Chung Resident Association) (Tung Chung)
(a)The sound level meter was
set on a tripod at a height of 1.2 m
above the podium for free-field
measurements at NMS5. A correction of +3 dB(A) shall be made to
the free field measurements.
(b)The battery condition was
checked to ensure the correct functioning of the meter.
(c)Parameters such as
frequency weighting, the time weighting and the measurement time were set as
follows:-
(i)frequency weighting: A
(ii)time weighting: Fast
(iii)time measurement: Leq(30-minutes) during non-restricted
hours i.e. 07:00 ¡V 1900 on normal weekdays
(e)Prior to and after each
noise measurement, the meter was calibrated using the acoustic calibrator for
94.0 dB(A) at 1000 Hz.If the
difference in the calibration level before and after measurement was more than
1.0 dB(A), the measurement would be considered invalid and repeat of noise
measurement would be required after re-calibration or repair of the equipment.
(f)During the monitoring
period, the Leq, L10 and L90
were recorded.In addition, site
conditions and noise sources were recorded on a standard record sheet.
(g)Noise measurement was
paused during periods of high intrusive noise (e.g. dog barking, helicopter
noise) if possible. Observations were recorded when intrusive noise was
unavoidable.
(h)Noise monitoring was
cancelled in the presence of fog, rain, wind with a steady speed exceeding 5m/s, or wind with gusts exceeding 10m/s. The wind speed shall be checked with a portable wind
speed meter capable of measuring the wind speed in m/s.
3.5.2Maintenance and Calibration
(a)The microphone head of the
sound level meter was cleaned with soft cloth at regular intervals.
(b)The meter and calibrator
were sent to the supplier or HOKLAS laboratory to check and calibrate at yearly
intervals.
(c)Calibration certificates
of the sound level meters and acoustic calibrators are provided in Appendix C.
3.6.1The schedule for construction noise monitoring in March
2016 is provided in Appendix
D.
3.7Monitoring
Results
3.7.1The monitoring
results for construction noise are summarized in Table 3.5 and the monitoring results and relevant graphical plots
are provided in Appendix
E.
4.1.1Impact water quality monitoring was carried out to
ensure that any deterioration of water quality is detected, and that timely
action is taken to rectify the situation.For impact water quality monitoring, measurements were taken in
accordance with the Contract Specific EM&A Manual. Table 4.1 shows the established Action/Limit Levels for the
environmental monitoring works.The ET proposed to amend the Acton Level
and Limit Level for turbidity and suspended solid and EPD approved ET¡¦s
proposal on 25 March 2013.Therefore,
Action Level and Limit Level for the Contract have been changed since 25 March
2013.
4.1.2The original and revised Action Level and
Limit Level for turbidity and suspended solid are shown in Table 4.1.
Table
4.1Action
and Limit Levels for Water Quality
Parameter (unit)
Water Depth
Action Level
Limit Level
Dissolved Oxygen (mg/L)
(surface, middle and bottom)
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.
4.3.1Table 4.3 summarises the monitoring parameters, frequency and
monitoring depths of impact water quality monitoring as required in the Contract
Specific EM&A Manual.
Table
4.3Impact
Water Quality Monitoring Parameters and Frequency
Three times per week
during mid-ebb and mid-flood tides (within ¡Ó 1.75 hour of the predicted time)
3
(1 m below water surface,
mid-depth and 1 m above sea bed, except where the water depth is less than 6
m, in which case the mid-depth station may be omitted. Should the water depth
be less than 3 m, only the mid-depth station will be monitored).
4.4.1In accordance with
the Contract Specific EM&A Manual, thirteen stations (6 Impact Stations, 5 Sensitive Receiver
Stations and 2 Control Stations) were designated for impact
water quality monitoring. The six Impact Stations
(IS) were chosen on the basis of their proximity to the reclamation and thus
the greatest potential for water quality impacts, the five Sensitive Receiver
Stations (SR) were chosen as they are close to the key sensitive receives and
the two Control Stations (CS) were chosen to facilitate comparison of the water
quality of the IS stations with less influence by the Project/ ambient water
quality conditions.
4.4.2The locations of these monitoring stations are
summarized in Table 4.4 and shown in
Figure 2.1.
Table 4.4
Impact
Water Quality Monitoring Stations
Monitoring Stations
Description
Coordinates
Easting
Northing
IS5
Impact Station (Close to
HKLR construction site)
811579
817106
IS(Mf)6
Impact Station (Close to
HKLR construction site)
812101
817873
IS7
Impact Station (Close to
HKBCF construction site)
812244
818777
IS8
Impact Station (Close to
HKBCF construction site)
814251
818412
IS(Mf)9
Impact Station (Close to
HKBCF construction site)
813273
818850
IS10
Impact Station (Close to HKBCF
construction site)
812577
820670
SR3
Sensitive receivers (San
Tau SSSI)
810525
816456
SR4
Sensitive receivers (Tai
Ho Inlet)
814760
817867
SR5
Sensitive receivers
(Artificial Reef In NE Airport)
811489
820455
SR10A
Sensitive receivers (Ma
Wan Fish Culture Zone)
823741
823495
SR10B
Sensitive receivers (Ma
Wan Fish Culture Zone)
823686
823213
CS2
Control Station (Mid-Ebb)
805849
818780
CS(Mf)5
Control Station
(Mid-Flood)
817990
821129
4.5Monitoring
Methodology
4.5.1Instrumentation
(a)The
in-situ water quality parameters including dissolved oxygen, temperature,
salinity and turbidity, pH were measured by multi-parameter meters.
4.5.2Operating/Analytical
Procedures
(a)Digital Differential Global Positioning Systems
(DGPS) were used to ensure that the correct location was selected prior to
sample collection.
(b)Portable, battery-operated echo sounders were used
for the determination of water depth at each designated monitoring station.
(c)All in-situ measurements were taken at 3 water
depths, 1 m below water surface, mid-depth and 1 m above sea bed, except where
the water depth was less than 6 m, in which case the mid-depth station was
omitted. Should the water depth be less than 3 m, only the mid-depth station
was monitored.
(d)At each measurement/sampling depth, two consecutive
in-situ monitoring (DO concentration and saturation, temperature, turbidity,
pH, salinity) and water sample for SS. The probes were retrieved out of the
water after the first measurement and then re-deployed for the second measurement.
Where the difference in the value between the first and second readings of DO
or turbidity parameters was more than 25% of the value of the first reading,
the reading was discarded and further readings were taken.
(e)Duplicate samples from each independent sampling
event were collected for SS measurement. Water samples were collected using the
water samplers and the samples were stored in high-density polythene bottles.
Water samples collected were well-mixed in the water sampler prior to pre-rinsing
and transferring to sample bottles. Sample bottles were pre-rinsed with the
same water samples. The sample bottles were then be packed in cool-boxes
(cooled at 4oC without being frozen), and delivered to ALS Technichem (HK) Pty Ltd. for the analysis of suspended
solids concentrations. The laboratory determination work would be started
within 24 hours after collection of the water samples. ALS Technichem
(HK) Pty Ltd. is a HOKLAS accredited laboratory and has comprehensive quality
assurance and quality control programmes.
(f)The analysis method and detection limit for SS is
shown in Table 4.5.
Table 4.5Laboratory
Analysis for Suspended Solids
Parameters
Instrumentation
Analytical Method
Detection Limit
Suspended Solid (SS)
Weighting
APHA 2540-D
0.5mg/L
(g)Other relevant data were recorded, including
monitoring location / position, time, water depth, tidal stages, weather
conditions and any special phenomena or work underway at the construction site
in the field log sheet for information.
4.5.3Maintenance and
Calibrations
(a)All in situ monitoring
instruments would be calibrated by ALS Technichem
(HK) Pty Ltd. before use and at 3-monthly intervals throughout all stages of
the water quality monitoring programme. The
procedures of performance check of sonde and testing
results are provided in Appendix C.
4.6.1The schedule for
impact water quality monitoring in March 2016 is provided in Appendix
D.
4.7Monitoring
Results
4.7.1Impact water quality
monitoring was conducted at all designated monitoring stations during the
reporting month. Impact water quality monitoring results and relevant graphical
plots are provided inAppendix
E.
4.7.2For marine water quality
monitoring, no Action Level and Limit Level exceedances of turbidity
level, dissolved oxygen level and suspended solid level were recorded during
the reporting month.
4.7.3Water quality impact
sources during water quality monitoring were the construction activities of the
Contract, nearby construction activities by other parties and nearby operating
vessels by other parties.
4.7.4The event action plan is annexed in Appendix
F.
5.1.1Impact dolphin monitoring is required to be conducted by a qualified dolphin specialist team to
evaluate whether there have
been any effects on the dolphins.
5.1.2The Action Level and Limit Level for dolphin monitoring are shown in Table 5.1.
Table
5.1Action
and Limit Levels for Dolphin Monitoring
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 encounter rate of number of dolphin sightings.
2.ANI means quarterly encounter rate of total number of dolphins.
3.For North Lantau Social Cluster, AL will be trigger if either NEL or NWL fall below the criteria; LL will
be triggered if both NEL and NWL
fall below the criteria.
5.1.3The revised Event and Action Plan for dolphin Monitoring was
approved by EPD in 6 May 2013. The revised Event and Action Plan is annexed in Appendix
F.
5.2.1According to the requirements of
the Updated EM&A Manual for HKLR (Version 1.0), dolphin monitoring programme should cover all transect lines in NEL and NWL
survey areas (see Figure 1 of Appendix H) twice per month. The
co-ordinates of all transect lines are shown in Table 5.2. The coordinates of several starting
points 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, and the revised coordinates are in red and marked with an asterisk in Table 5.2.
Table 5.2Co-ordinates
of Transect Lines
Line No.
Easting
Northing
Line No.
Easting
Northing
1
Start Point
804671
815456*
13
Start Point
816506
819480
1
End Point
804671
831404
13
End Point
816506
824859
2
Start Point
805475
815913*
14
Start Point
817537
820220
2
End Point
805477
826654
14
End Point
817537
824613
3
Start Point
806464
819435
15
Start Point
818568
820735
3
End Point
806464
822911
15
End Point
818568
824433
4
Start Point
807518
819771
16
Start Point
819532
821420
4
End Point
807518
829230
16
End Point
819532
824209
5
Start Point
808504
820220
17
Start Point
820451
822125
5
End Point
808504
828602
17
End Point
820451
823671
6
Start Point
809490
820466
18
Start Point
821504
822371
6
End Point
809490
825352
18
End Point
821504
823761
7
Start Point
810499
820880*
19
Start Point
822513
823268
7
End Point
810499
824613
19
End Point
822513
824321
8
Start Point
811508
821123*
20
Start Point
823477
823402
8
End Point
811508
824254
20
End Point
823477
824613
9
Start Point
812516
821303*
21
Start Point
805476
827081
9
End Point
812516
824254
21
End Point
805476
830562
10
Start Point
813525
820872
22
Start Point
806464
824033
10
End Point
813525
824657
22
End Point
806464
829598
11
Start Point
814556
818853*
23
Start Point
814559
821739
11
End Point
814556
820992
23
End Point
814559
824768
12
Start Point
815542
818807
12
End Point
815542
824882
Note:
Co-ordinates in red and marked with asterisk are revised co-ordinates of
transect line.
5.2.2The
survey team used standard line-transect methods (Buckland et al. 2001) to
conduct the systematic vessel surveys, and followed the same technique of data
collection that has been adopted over the last 18 years of marine mammal monitoring
surveys in Hong Kong developed by HKCRP (see Hung 2015).For each monitoring vessel survey, a
15-m inboard vessel with an open upper deck (about 4.5 m above water surface)
was used to make observations from the flying bridge area.
5.2.3Two
experienced observers (a data recorder and a primary observer) made up the
on-effort survey team, and the survey vessel transited different transect lines
at a constant speed of 13-15 km per hour.The data recorder searched with unaided eyes and filled out the
datasheets, while the primary observer searched for dolphins and porpoises
continuously through 7 x 50 Fujinon marine
binoculars.Both observers searched
the sea ahead of the vessel, between 270o and 90o (in
relation to the bow, which is defined as 0o).One to two additional experienced
observers were available on the boat to work in shift (i.e. rotate every 30
minutes) in order to minimize fatigue of the survey team members.All observers were experienced in small
cetacean survey techniques and identifying local cetacean species.
5.2.4During
on-effort survey periods, the survey team recorded effort data including time,
position (latitude and longitude), weather conditions (Beaufort sea state and
visibility), and distance travelled in each series (a continuous period of
search effort) with the assistance of a handheld GPS (Garmin eTrex Legend).
5.2.5Data
including time, position and vessel speed were also automatically and
continuously logged by handheld GPS throughout the entire survey for subsequent
review.
5.2.6When
dolphins were sighted, the survey team would end the survey effort, and
immediately record the initial sighting distance and angle of the dolphin group
from the survey vessel, as well as the sighting time and position.Then the research vessel was diverted
from its course to approach the animals for species identification, group size
estimation, assessment of group composition, and behavioural
observations.The perpendicular
distance (PSD) of the dolphin group to the transect line was later calculated
from the initial sighting distance and angle.
5.2.7Survey
effort being conducted along the parallel transect lines that were
perpendicular to the coastlines (as indicated in Figure 1 of Appendix H) was labeled as ¡§primary¡¨ survey effort,
while the survey effort conducted along the connecting lines between parallel
lines was labeled as ¡§secondary¡¨ survey effort.According to HKCRP long-term dolphin
monitoring data, encounter rates of Chinese white dolphins deduced from effort
and sighting data collected along primary and secondary lines were similar in
NEL and NWL survey areas.Therefore, both primary and secondary survey effort were presented as
on-effort survey effort in this report.
5.2.8Encounter
rates of Chinese White Dolphins (number of on-effort sightings per 100 km of
survey effort and number of dolphins from all on-effort sightings 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.Only data collected under Beaufort 3 or
below condition would be used for encounter rate analysis.Dolphin encounter rates were calculated
using primary survey effort alone, as well as the combined survey effort from
both primary and secondary lines.
Photo-identification Work
5.2.9When a
group of Chinese White Dolphins were sighted during the line-transect survey,
the survey team would end effort and approach the group slowly from the side
and behind to take photographs of them.Every attempt was made to photograph every dolphin in the group, and
even photograph both sides of the dolphins, since the colouration
and markings on both sides may not be symmetrical.
5.2.10A
professional digital cameras (Canon EOS 7D and 60D models), equipped with long
telephoto lenses (100-400 mm zoom), were available on board for researchers to
take sharp, close-up photographs of dolphins as they surfaced.The images were shot at the highest
available resolution and stored on Compact Flash memory cards for downloading
onto a computer.
5.2.11All
digital images taken in the field were first examined, and those containing
potentially identifiable individuals were sorted out.These photographs would then be examined
in greater detail, and were carefully compared to the existing Chinese White
Dolphin photo-identification catalogue maintained by HKCRP since 1995.
5.2.12Chinese
White Dolphins can be identified by their natural markings, such as nicks,
cuts, scars and deformities on their dorsal fin and body, and their unique
spotting patterns were also used as secondary identifying features (Jefferson
2000).
5.2.13All
photographs of each individual were then compiled and arranged in chronological
order, with data including the date and location first identified (initial
sighting), re-sightings, associated dolphins, distinctive features, and age
classes entered into a computer database.Detailed information on all identified individuals will be further
presented as an appendix in quarterly EM&A reports.
5.3.1During the month of March 2016,
two sets of systematic line-transect vessel surveys were conducted on the
7th, 11th, 22nd and 23rdto
cover all transect lines in NWL and NEL survey areas twice. The survey routes of each survey day are presented in Figures 2 to 5
of Appendix H.
5.3.2From
these surveys, a total of 290.32
km of survey effort was collected,with
95.5% of the total survey effort being
conducted under favourable weather conditions (i.e. Beaufort Sea State 3 or below with good
visibility) (Annex I of Appendix H).
Among the two areas109.30
km and 181.02
km of survey effort were collected from
NEL and NWL survey areas respectively.Moreover,
the total survey effort conducted on primary lines was
218.00 km, while the effort on secondary lines
was 72.32
km.
5.3.3During the two sets of monitoring surveys in
March 2016,
only two groups
of four
Chinese White Dolphins were sighted(Annex II of
Appendix H). Both dolphin sightings were made in NWL,
while none was sighted in NEL.
5.3.4During the
March¡¦s surveys, only one of the two dolphin sightings
was made on primary lines during
on-effort search, and neither group
was associated with any operating
fishing vessel.
5.3.5Distribution of these dolphin sightings made in
March 2016 is shown in Figure
6 of Appendix H. One group of three dolphins was sighted
between Black Point and Lung Kwu Chau, while the other
group with a lone dolphin was sighted just to the north of HKBCF, which was
traveling toward the northern end of the airport platform (Figure 6 of Appendix H).
5.3.6None
of the dolphin sightings were located in the proximity of the HKLR03
reclamation sites as well as the HKLR09/TMCLKL alignments (Figure 6 of Appendix H). However, one sighting was made to the north of the
HKBCF reclamation site, where dolphin occurrence has been extremely rare in the
past few years (Figure 6 of
Appendix H).
5.3.7During
the March¡¦s surveys, encounter rates of Chinese White Dolphins deduced from
the survey effort and on-effort sighting data made under favourable
conditions (Beaufort 3 or below) are shown in Table 5.3 and Table
5.4.
5.3.8The average dolphin group size in March
2016 was 2.0 individuals per group, which was much lower than the ones in
previous months of monitoring surveys. Both dolphin groups were small in size
with one and three individuals respectively.
(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)
PrimaryLines Only
Both Primary and Secondary Lines
PrimaryLines Only
Both Primary and Secondary Lines
Northeast
Lantau
0.0
0.0
0.0
0.0
Northwest
Lantau
0.7
0.6
2.2
1.8
Remarks:
1.Monthly Average Dolphin Encounter Rates (Sightings Per 100 km of
Survey Effort) from All Four Surveys Conducted in March 2016 on Primary Lines only as well as Both Primary
Lines and Secondary Lines in Northeast (NEL) and Northwest Lantau (NWL).
Photo-identification Work
5.3.9Four individual dolphins were sighted
four times during March¡¦s surveys (Annex
III and IV of Appendix H). All individuals were
sighted only once during the monitoring month..
5.3.10None of these individual
dolphins were accompanied with their calves during their re-sightings, as in
recent monitoring months during the HKLR03 monitoring surveys.
Conclusion
5.3.11During this month of dolphin monitoring, no adverse impact from the
activities of this construction project on Chinese White Dolphins was
noticeable from general observations.
5.3.12Due to monthly variation in dolphin occurrence within the study
area, it would be more appropriate to draw conclusion on whether any impacts on
dolphins have been detected related to the construction activities of this
project in the quarterly EM&A report, where comparison on distribution,
group size and encounter rates of dolphins between the quarterly impact
monitoring period (March ¡V May 2016) and baseline monitoring period
(3-month period) will be made.
5.4Reference
5.4.1Buckland,
S. T., Anderson, D. R., Burnham, K. P., Laake, J. L.,
Borchers, D. L., and Thomas, L.2001.Introduction to distance sampling:
estimating abundance of biological populations.Oxford University Press, London.
5.4.2Hung,
S. K.2015.Monitoring of Marine Mammals in Hong
Kong waters: final report (2014-15).An unpublished report submitted to the Agriculture, Fisheries and
Conservation Department, 198 pp.
5.4.3Jefferson, T. A.2000.Population biology of the Indo-Pacific
hump-backed dolphin in Hong Kong waters.Wildlife Monographs 144:1-65.
6.1.1To avoid disturbance
to the mudflat and nuisance to navigation, no fixed marker/monitoring rod was
installed at the monitoring stations. A high precision Global Navigation
Satellite System (GNSS) real time location fixing system (or equivalent
technology) was used to locate the station in the precision of 1mm, which is
reasonable under flat mudflat topography with uneven mudflat surface only at
micro level.This method has been
used on Agricultural Fisheries and Conservation Department¡¦s (AFCD) project, namely
Baseline Ecological Monitoring Programme for the Mai Po Inner Deep Bay Ramsar Site for measurement of seabed levels.
6.1.2Measurements were
taken directly on the mudflat surface.The Real Time Kinematic GNSS (RTK GNSS) surveying technology was used to
measure mudflat surface levels and 3D coordinates of a survey point.The RTK GNSS survey was calibrated
against a reference station in the field before and after each survey.The reference station is a survey
control point established by the Lands Department of the HKSAR Government or
traditional land surveying methods using professional surveying instruments
such as total station, level and/or geodetic GNSS.The coordinates system was in HK1980
GRID system.For this contract, the
reference control station was surveyed and established by traditional land
surveying methods using professional surveying instruments such as total
station, level and RTK GNSS.The
accuracy was down to mm level so that the reference control station has
relatively higher accuracy.As the
reference control station has higher accuracy, it was set as true evaluation
relative to the RTK GNSS measurement.All position and height correction were adjusted and corrected to the
reference control station.Reference station survey result and professional land surveying
calibration is shown as Table 6.1:
Table 6.1Reference
Station Survey result and GNSS RTK calibration result of Round 1
Reference
Station
Easting (m)
Northing
(m)
Baseline
reference elevation (mPD) (A)
Round 1
Survey (mPD) (B)
Calibration
Adjustment (B-A)
T1
811248.660mE
816393.173mN
3.840
3.817
-0.023
T2
810806.297mE
815691.822mN
4.625
4.653
+0.028
T3
810778.098mE
815689.918mN
4.651
4.660
+0.009
T4
810274.783mE
816689.068mN
2.637
2.709
+0.072
6.1.3The precision of the
measured mudflat surface level reading (vertical precision setting) was within
10 mm (standard deviation) after averaging the valid survey records of the XYZ
HK1980 GRID coordinates.Each survey
record at each station was computed by averaging at least three measurements
that are within the above specified precision setting. Both digital data
logging and written records were collected in the field.Field data on station fixing and mudflat
surface measurement were recorded.
Monitoring Locations
6.1.4Four monitoring
stations were established based on the site conditions for the sedimentation
monitoring and are shown in Figure
6.1.
Monitoring Results
6.1.5The 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 6.2 and Table 6.3.
Table 6.2Measured
Mudflat Surface Level Results
Baseline
Monitoring (September 2012)
Impact
Monitoring (March 2016)
Monitoring Station
Easting (m)
Northing (m)
Surface Level
(mPD)
Easting (m)
Northing (m)
Surface Level
(mPD)
S1
810291.160
816678.727
0.950
810291.129
816678.735
1.135
S2
810958.272
815831.531
0.864
810958.294
815831.517
1.007
S3
810716.585
815953.308
1.341
810716.586
815953.341
1.487
S4
811221.433
816151.381
0.931
811221.528
816151.433
1.176
Table 6.3Comparison
of measurement
Comparison
of measurement
Remarks and Recommendation
Monitoring
Station
Easting
(m)
Northing
(m)
Surface
Level
(mPD)
S1
-0.031
0.008
0.185
Level continuously
increased
S2
0.022
-0.014
0.143
Level continuously
increased
S3
0.001
0.033
0.146
Level continuously
increased
S4
0.095
0.052
0.245
Level continuously
increased
6.1.6This measurement result was
generally and relatively higher than the baseline measurement at S1, S2, S3 and
S4. The mudflat level is continuously increased.
6.2.1The 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.
6.2.2Impact water quality
monitoring in San Tau (monitoring station SR3) was conducted in March 2016.The monitoring parameters included
dissolved oxygen (DO), turbidity and suspended solids (SS).
6.2.3The Impact
monitoring results for SR3 were extracted and summarised below:
Table 6.4Impact
Water Quality Monitoring Results (Depth Average)
6.3.1In 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 I). The horizontal length of sampling
zones TC1, TC2, TC3 and ST were about 250m, 300m, 300m and 250m, respectively.
Survey of horseshoe crabs, seagrass beds and intertidal communities were
conducted in every sampling zone. The present survey
was conducted in March 2016 (totally 6
sampling days between 8thand 26th March 2016).
Horseshoe Crabs
6.3.2Active 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 8th (for TC3), 13th (for TC1), 20th
(for TC2), 22nd (for ST) and 26th (second survey for TC1)
March 2016. The weather was generally cloudy for all day time surveys (13th-26th
Mar) while it was humid during the night time survey (8th Mar).
Since there was intermittent rain during the survey for TC1 on 13th
Mar, the horseshoe crab trail would cease that searching became difficult.
Hence a second survey was conducted on 26th Mar under cloudy
weather.
Seagrass Beds
6.3.3Active 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 8th (for TC3), 13th (for TC1), 20th
(for TC2) and 22nd (for ST) March 2016. The weather was cloudy and
cold for all day time surveys (13th-22nd Mar) while it
was humid during the night time survey (8th Mar).
Intertidal Soft Shore Communities
6.3.4The intertidal soft shore community surveys were conducted in low tide
period 8th (for TC3), 12th (for ST), 13th (for
TC1) and 20th (for TC2) March 2016. 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.
6.3.5Inside a quadrat, any visibleepifauna
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.
6.3.6All 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.
6.3.7The 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
6.3.8Data collected from
direct search and core sampling was pooled in every quadrat for data analysis.
Shannon-Weaver Diversity Index (H¡¦) and Pielou¡¦s
Species Evenness (J) were calculated for every quadrat using the formulae
below,
H¡¦= -£U ( Ni / N ) ln ( Ni / N ) (Shannon and Weaver,
1963)
J = H¡¦ / ln
S, (Pielou, 1966)
where S is the total number of species in the sample,
N is the total number of individuals, and Ni is the number of individuals of
the ith species.
6.4.1In the event of the impact monitoring results
indicating that the density or the distribution pattern of intertidal fauna and
seagrass is found to be significant different to the baseline condition (taking
into account natural fluctuation in the occurrence and distribution pattern
such as due to seasonal change), appropriate actions should be taken and
additional mitigation measures should be implemented as necessary.Data should then be re-assessed and the
need for any further monitoring should be established.The action plan, as given in Table 6.5 should be undertaken within a
period of 1 month after a significant difference has been determined.
Table 6.5Event
and Action Plan for Mudflat Monitoring
Event
ET Leader
IEC
SO
Contractor
Density or the distribution pattern of horseshoe
crab, seagrass or intertidal soft shore communities recorded in the impact or
post-construction monitoring aresignificantly lower than or different from those recorded in the baseline
monitoring.
Review historical data to ensure
differences are as a result of natural variation or previously observed
seasonal differences;
Identify source(s) of impact;
Inform the IEC, SO and Contractor;
Check monitoring data;
Discuss additional monitoring and any other
measures, with the IEC and Contractor.
Discuss monitoring with the ET and the
Contractor;
Review proposals for additional monitoring
and any other measures submitted by the Contractor and advise the SO
accordingly.
Discuss with the IEC additional monitoring
requirements and any other measures proposed by the ET;
Make agreement on the measures to be
implemented.
Inform the SO and in writing;
Discuss with the ET and the IEC and propose
measures to the IEC and the ER;
6.5.1In the present survey, two
species of horseshoe crab Carcinoscorpiusrotundicauda (total 23 ind.)
and Tachypleustridentatus (total 17 ind.) were recorded. For one sight record, grouping of
2-8 individuals was observed at same locations with similar substratum (fine sand or soft mud). Photo records were shown in Figure 3.1of Appendix Iwhile the complete records of horseshoe crab were shown inAnnex II of Appendix I.
6.5.2Table 3.1 of
Appendix Isummarizes the survey results of horseshoe crab in present survey. For Carcinoscorpiusrotundicauda, there were 21 and 2 individuals in TC3 and ST respectively. For TC3, the search record was 3.5ind. hr-1 person-1 while the average body size was 35.49 mm (prosomal width ranged 25.53-48.12
mm). For ST, the search record was 0.3ind. hr-1
person-1 while the average body size
was 35.70 mm (prosomal width ranged 16.82-54.58 mm). No individual was found in TC1 and TC2.
6.5.3For Tachypleustridentatus, there was 17 individuals recorded in TC3 only. The search record was 2.8ind. hr-1 person-1 while the average body size was 41.83 mm (prosomal width ranged 26.79-48.91 mm).
6.5.4In the previous survey of March
2015, there was one important finding that a mating pair of Carcinoscorpiusrotundicauda was found in ST (prosomal width: male 155.1 mm, female 138.2 mm)(Figure 3.2 of Appendix I). It indicated the importance of ST as a breeding ground of horseshoe
crab. Moreover, two moults of Carcinoscorpiusrotundicauda were found in TC1 with similar prosomal width 130-140 mm (Figure 3.2 of Appendix I). 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 Carcinoscorpiusrotundicauda (prosomal width 117.37 mm and
178.17 mm) were excluded from data analysis according to the same principle.
6.5.5No 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.
6.5.6The 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
6.5.7Figures 3.3 and 3.4 of Appendix I show the changes of number of individuals, mean prosomal width and
search record of horseshoe crabs Carcinoscorpiusrotundicaudaand Tachypleustridentatus
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. In March 2016 (present survey), higher search record was noticed
in TC3 again. For TC1, the search record was at low to medium level and the
number of both species could fluctuate along the sampling months. Relatively,
search record was very low in TC2 (2 ind. in Sep.
2013, 1 ind. in Mar., Jun., Sep. 2014, Mar. and Jun
2015, 4 ind. in Sep. 2015). For the body size, larger
individuals of Carcinoscorpiusrotundicauda were usually found in ST and TC1
relative to those in TC3. For Tachypleustridentatus, larger individuals were also found in ST followed by TC3 and TC1.
6.5.8Throughout 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
6.5.9Throughout 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 I). In December 2013, no
individual of horseshoe crab was found. In December 2014, 2 individuals
of Carcinoscorpiusrotundicauda and 8 individuals of Tachypleustridentatus were found only.In December 2015, 2 individuals of Carcinoscorpiusrotundicauda, 6 individuals of Tachypleustridentatus 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.
6.5.10Between the sampling months September 2012 and December 2013, Carcinoscorpiusrotundicauda was
a less common species relative to Tachypleustridentatus. 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 (i.e. more conspicuous walking trail).
6.5.11For Tachypleustridentatus, 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 fluctuated in TC3 while it decreased steadily in ST until
September. 2015. Apart from natural mortality, migration from nursery soft
shore to subtidal habitat was another possible cause. Since the mean prosomal
width of Tachypleustridentatus 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.
6.5.12Since 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
6.5.13Figure 3.5 of Appendix I
shows the changes of
prosomal width of Carcinoscorpiusrotundicauda and Tachypleustridentatus in TC3. As mentioned above, Carcinoscorpiusrotundicauda 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 Carcinoscorpiusrotundicauda in
TC3. It matched with the previous mating record in ST in March 2015.
6.5.14For Tachypleustridentatus, 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.
6.5.15From June 2015 to March 2016 (present survey), slight increasing trends
of major size were noticed for both species. It might be accounted by new round
of spawning. But it was yet to conclude until wet season results (June &
September 2016) were available.
Box plot of horseshoe crab populations in ST
6.5.16Figure 3.6 of Appendix I
shows the changes of
prosomal width of Carcinoscorpiusrotundicauda and Tachypleustridentatus in ST. As mentioned above, Carcinoscorpiusrotundicauda 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 Carcinoscorpiusrotundicauda 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.
6.5.17For Tachypleustridentatus, 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, two big individuals (prosomal width
89.27 mm and 98.89 mm) were recorded only while it could not represent the
major population.
6.5.18From
December 2015 to March 2016 (present survey), the number of horseshoe crab
recorded was very few in ST. Hence the population change of both species could
not be determined.
6.5.19As a summary for horseshoe crab
populations in TC3 and ST, there was successful spawning of Carcinoscorpiusrotundicauda
from 2014 to 2015 while the spawning time should be in spring. There were
consistent, increasing trends of population size in these two sampling zones.
For Tachypleustridentatus,
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
6.5.20The present survey was the 14th
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 wet season, large number of dead individuals on the shore)
is observed, it would be reported as soon as possible.
Seagrass Beds
6.5.21In the present survey, seagrass was found
in ST only. Two seagrass
species Halophilaovalis
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. The seagrass bed existed in irregular patches or long strand in
various sizes. For one long strand, two seagrass species were found coexisting
in variable coverage. Photo records were shown in Figure
3.7 of Appendix I while the complete records of seagrass beds survey were shown in Annex III of Appendix
I.
6.5.22Table 3.2 of Appendix Isummarize the results of seagrass beds survey in ST. Eight patches of Halophilaovaliswere found while the total seagrass bed area was about 230.6 m2 (average area 28.8 m2). The largest patch was
a horizontal strand with seagrass bed area 100.4 m2. It coexisted
with another seagrass speciesand remained at very low coverage (10%).
Other three horizontal strands were at medium size (15.8-41.1 m2)
and high coverage (80-100%). The rest were small patches (1.5-17.3 m2)
and variable coverage (20-90%). For Zostera japonica, it was mainly found
coexisting with Halophilaovalis in the largest strand(100.4 m2) of seagrass
bed with high coverage 90%.
6.5.23Since majority of seagrass bed was confined in ST, the temporal change
of both seagrass species were investigated in details.
Temporal
variation of seagrass beds
6.5.24Figure 3.8 of Appendix Ishows 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 Halophilaovalis. 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 Halophilaovalis resulting in less competition
for substratum and nutrients. From September 2015 to March 2016, it was found
coexisting with seagrass Halophilaovalis with steady increasing patch
size and variable coverage.
6.5.25For Halophilaovalis, 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 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 ¡V 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, Halophilaovalis
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.
6.5.26In December 2014, all the seagrass patches of Halophilaovalis disappeared in ST. Figure 3.9 of Appendix I 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 Halophilaovalis 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 Halophilaovalis
6.5.27Typhoon or strong water current was
suggested as one unfavourable condition to Halophilaovalis (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.
6.5.28Prolonged light deprivation due to turbid water would be another unfavouable condition. Previous studies reported that Halophilaovalis 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 Longstaffet 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).
6.5.29In 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.
6.5.30Based 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 Halophilaovalisthat leaded to disappearance of this short-lived and r-strategy seagrass species. Fortunately
Halophilaovalis was a fast-growing species (Vermaatet 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 Halophilaovalis 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
6.5.31Figure 3.9 of Appendix I shows the changes of seagrass bed area at ST. From March to June 2015, 2-3 small
patches of Halophilaovalis 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 Halophilaovalis at certain degree. From June to March 2016, the total seagrass area of Halophilaovalis had
increased rapidly from 6.8 m2 to 230.63 m2. It had
recolonized its original patch locations and covered Zostera
japonica. Hence it was expected that the seagrass bed of Halophilaovalis would
increase continually in the following months.
Impact of the HKLR project
6.5.32The present survey was the 14th survey of the EM&A programme during the construction period. According to the
results of present survey,there was recolonization of both
seagrass species Halophilaovalis 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
6.5.33Table 3.3 and Figure 3.10 of Appendix I 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:
¡PIn TC1, high percentage of ¡¥Gravels and Boulders¡¦ (80-90%) was recorded
at high and mid tidal levels. ¡¥Gravels and Boulders¡¦ (60%) and ¡¥Sands¡¦ (30%)
were the major substratum types at low tidal level.
¡PIn TC2, high percentage of ¡¥Soft mud¡¦ (80%) was recorded at all tidal
levels.
¡PIn TC3, the substratum type was clearly different between high-mid tidal
level and low tidal level. ¡¥Sands¡¦ (50-60%) and ¡¥Soft mud¡¦ (40-50%) were the
major substratum types at high and mid tidal levels. High percentage of
¡¥Gravels and Boulders¡¦ (90%) was recorded at low tidal level.
¡PIn 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 ¡¥Soft mud¡¦ (80%) was recorded followed by ¡¥Gravels and Boulders¡¦
(20%).
6.5.34There 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.
6.5.35Table 3.4 of Appendix I lists the total abundance, density
and number of taxon of every phylum in this
survey. A total of 11728 individuals were recorded. Mollusca was
significantly the most abundant phylum (total individuals 11496, density 383 ind.
m-2, relative abundance 98.0%). The
second abundant phylum was Arthropoda (127ind., 4ind. m-2, 1.1%). The less abundant phyla wereAnnelida
(62ind., 2ind. m-2,
0.5%) andCnidaria (17ind., 1ind. m-2,
0.1%). 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 (10 taxa). There was 1 taxon recorded only for other phyla. The taxonomic resolution and complete list of collected specimens areshown in Annex IV and V of Appendix I.
6.5.36Table 3.5of
Appendix I shows the number of individual, relative abundance and density of each
phylum in every sampling zone. The total abundance (2313-4085 ind.) varied among the four sampling zones while the phyla distributionswere
similar. In general, Molluscawas the
most dominant phylum (no. of individuals: 2213-4054ind.; relative abundance 95.7-99.2%; density 295-541 ind. m-2). Other phyla were significantly lower in number of individuals. Arthropoda was the
second abundant phylum (15-68ind.;0.4-2.9%; 2-9 ind.
m-2). Annelida was the third abundant phylum in TC1, TC2 and TC3 (7-26 ind.;
0.2-1.1%; 1-3 ind. m-2) while it was the
fourth abundant in ST (8 ind.; 0.3%; 1 ind. m-2). Cnidaria
(sea anemone) was the third abundant phylum (15 ind.; 0.6%; 2 ind.
m-2) in ST.Relatively other phyla were low in abundance in all sampling zones (≤ 0.1%).
Dominant species in every sampling zone
6.5.37Table 3.6of
Appendix I lists the abundant species (relative abundance >10%) in every sampling zone. In TC1,
gastropod Batillariamultiformis was the
most abundant species of very high density (620 ind. m-2,
relative abundance 84%)at high tidal level (major substratum: ¡¥Gravels
and Boulders¡¦). At mid tidal level (major substratum: ¡¥Gravels and Boulders¡¦),
gastropod Batillariamultiformis was also
the most abundant species of high density (214 ind. m-2,
relative abundance 47%) followed by gastropod Monodontalabio (81ind. m-2, 18%) and rock
oyster Saccostrea cucullata (70 ind. m-2, 16%, attached on boulders) at
moderate densities. At low tidal level (major substratum: ¡¥Gravels and Boulders¡¦),
rock oyster Saccostrea
cucullata was the
most abundant species of moderate-high density (141ind. m-2,
32%) followed by gastropods Monodontalabio (98 ind. m-2, 22%), Batillariazonalis (51ind. m-2, 11%) and Batillariamultiformis (47ind. m-2,
10%) at moderate densities.
6.5.38At TC2, gastropod
Cerithideadjadjariensis(123 ind. m-2, 32%) was
the most abundant at moderate density followed by gastropods Batillariamultiformis (69ind. m-2,
18%)Cerithideacingulata (41ind. m-2,
11%) and rock oyster Saccostrea cucullata (67ind. m-2,
17%)at high tidal level (major
substratum: ¡¥Soft mud¡¦).At mid
and low tidal levels (major substrata: ¡¥Soft mud¡¦), rock oyster Saccostrea cucullata
(102-103ind. m-2,
32-45%) was
the most abundant followed by gastropod Batillariazonalis (48-95 ind. m-2, 22-30%). Besides,
gastropod Cerithideadjadjariensis(34ind. m-2,
11%) was the third abundant at mid tidal level.
6.5.39At TC3, the abundant species were quite
different between three tidal levels. At high tidal level (major substratum: ¡¥Sands¡¦), gastropod Batillariamultiformis was the
most abundant species of high density (268ind. m-2, 59%) followed
by gastropod Cerithideadjadjariensis (123ind. m-2,
27%). At mid tidal level (major substratum:
¡¥Sands¡¦), the abundant species were at moderate densities including gastropods Cerithideadjadjariensis (86ind. m-2,
32%), Cerithideacingulata(55ind. m-2,
21%), Batillariamultiformis (51ind. m-2,
19%) and Batillariazonalis (46ind. m-2,
17%). At low tidal level (major substratum: ¡¥Gravels and Boulders¡¦), the
abundant species were at moderate densities including rock oyster Saccostrea cucullata
(143ind. m-2, 31%), gastropods
Monodontalabio (127 ind. m-2, 27%) and Batillariamultiformis (125ind. m-2,
27%).
6.5.40At ST, gastropod gastropodsMonodontalabio(166 ind. m-2, 42%) and Batillariamultiformis (120ind. m-2,
31%) were of moderate densities followed byrock oyster Saccostrea cucullata (48ind. m-2,
12%) at high tidal level (major substratum: ¡¥Gravels
and Boulders¡¦). At mid tidal level (major substratum: ¡¥Gravels and Boulders¡¦), rock oyster Saccostrea cucullata (176ind. m-2,
39%) and gastropod Monodontalabio(120 ind. m-2, 26%)
became abundant followed by gastropod Lunellacoronata(61ind. m-2,
13%). At low tidal level (major substratum: ¡¥Soft
mud¡¦), rock oyster Saccostrea cucullata(34ind. m-2,
38%) and gastropod Lunellacoronata(19ind. m-2,
21%) were at low densities.
6.5.41In 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 Batillariamultiformis(total
number of individuals: 3864 ind., relative abundance 32.9%),
Cerithideadjadjariensis (1103
ind., 9.4%) and Batillariazonalis (713 ind., 6.1%) were the most commonly occurring species on
sandy and soft mud substrata. Rock oyster Saccostrea cucullata(2263 ind., 19.3%), gastropods Monodontalabio (1706 ind., 14.5%)
were commonly occurring species inhabiting
gravel and boulders substratum.
Biodiversity and abundance of soft shore
communities
6.5.42Table 3.7of
Appendix Ishows 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, there
was no clear difference on mean species number (7-9 spp. 0.25 m-2),
mean H¡¦ (1.2-1.5) and mean J (0.5-0.7). The mean density of TC1 (545
ind. m-2) was higher than other sampling
zones (308-398 ind. m-2).
6.5.43Across 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 TC1, TC2 and ST. As
mentioned, the variation of mean density should be determined by the type of substratum primarily.
6.5.44Figures 3.11 to 3.14 of Appendix I 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
6.5.45The present survey was the fourteenth
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.
6.6.1Chan, K.K., Caley, K.J., 2003. Sandy Shores, Hong Kong Field Guides 4.
The Department of Ecology & Biodiversity, The University of Hong Kong. pp
117.
6.6.2Dai, A.Y., Yang, S.L., 1991. Crabs of the China Seas. China Ocean Press.
Beijing.
6.6.3Dong, Y.M., 1991. Fauna of ZheJiang Crustacea.
Zhejiang Science and Technology Publishing House. ZheJiang.
6.6.4EPD, 1997. Technical Memorandum on Environmental Impact Assessment Process
(1st edition). Environmental Protection Department, HKSAR Government.
6.6.5Fauchald, K., 1977. The polychaete worms. Definitions and keys to the orders,
families and genera. Natural History Museum of Los Angeles County, Science
Series 28. Los Angeles, U.S.A.
6.6.6Fong, C.W., 1998. Distribution of Hong Kong seagrasses. In: Porcupine! No. 18. The School of
Biological Sciences, The University of Hong Kong, in collaboration with Kadoorie Farm & Botanic Garden Fauna Conservation
Department, p10-12.
6.6.7Li, H.Y., 2008. The Conservation of Horseshoe Crabs in Hong Kong. MPhil
Thesis, City University of Hong Kong, pp 277.
6.6.8Longstaff, B.J., Dennison, W.C., 1999.
Seagrass survival during pulsed turbidity events: the effects of light
deprivation on the seagrasses Halodulepinifolia and Halophilaovalis. Aquatic Botany 65 (1-4), 105-121.
6.6.9Longstaff, B.J., Loneragan,
N.R., O¡¦Donohue, M.J., Dennison, W.C., 1999. Effects
of light deprivation on the survival and recovery of the seagrass Halophilaovalis (R.
Br.) Hook. Journal of Experimental Marine Biology and Ecology 234 (1), 1-27.
6.6.10Nakaoka, M., Aioi,
K., 1999. Growth of seagrass Halophilaovalis at dugong trails compared to existing
within-patch variation in a Thailand intertidal flat. Marine Ecology Progress
Series 184, 97-103.
6.6.11Pielou, E.C., 1966. Shannon¡¦s formula
as a measure of species diversity: its use and misuse. American Naturalist 100,
463-465.
6.6.12Qi, Z.Y., 2004. Seashells of
China. China Ocean Press. Beijing, China.
6.6.13Qin, H., Chiu, H., Morton, B.,
1998. Nursery beaches for Horseshoe Crabs in Hong Kong. In: Porcupine! No. 18. The School of
Biological Sciences, The University of Hong Kong, in collaboration with Kadoorie Farm & Botanic Garden Fauna Conservation
Department, p 9-10.
6.6.14Shannon, C.E., Weaver, W., 1963.
The Mathematical Theory of Communication. Urbana:
University of IllinoisPress, USA.
6.6.15Shin, P.K.S., Li, H.Y., Cheung,
S.G., 2009. Horseshoe Crabs in Hong Kong: Current Population Status and Human
Exploitation. Biology and Conservation of Horseshoe Crabs (part 2), 347-360.
6.6.16Supanwanid, C., 1996. Recovery of the
seagrass Halophilaovalis after
grazing by dugong. In: Kuo, J., Philips, R.C., Walker,
D.I., Kirkman, H. (eds),
Seagrass biology: Proc Int workshop, Rottenest
Island, Western Australia. Faculty of Science, The University of Western
Australia, Nedlands, 315-318.
6.6.17Vermaat, J.E., Agawin,
N.S.R., Duarte, C.M., Fortes, M.D., Marba. N., Uri, J.S.,
1995. Meadow maintenance, growth and productivity of a mixed Philippine
seagrass bed. Marine Ecology Progress Series 124, 215-225.
6.6.18Yang, D.J, Sun, R.P., 1988. Polychaetous annelids commonly seen from the Chinese waters
(Chinese version). China Agriculture Press, China.
7.1.1Site Inspections
were carried out on a weekly basis to monitor the implementation of proper
environmental pollution control and mitigation measures for the Project. During
the reporting month, five site inspections were carried out on 3, 9, 16, 23 and 29 March 2016.
7.1.2A summary of observations
found during the site inspections and the follow up actions taken by the Contractor are described in Table 7.1.
Table 7.1Summary
of Environmental Site Inspections
Date of Audit
Observations
Actions Taken
by Contractor / Recommendation
Date of
Observations Closed
26 Feb 2016
1.Gap between two silt
curtains were observed at Portion X.
2.Stagnant water was observed
at S8. Prompt removal of stagnant water was needed to avoid mosquito
breeding.
3.It was unclear about the
source of effluent discharge at S11.
4.A gap was observed along the
bund at S11.
5.Rubbish was accumulated at
S11.
6.Black smoke emitting from a
piling rig was observed at S15.
7.No drip tray was provided
for chemical drums at S15.
8.Stagnant water was observed
at S15.
9.No drip tray was provided
for a chemical container at S15.
1.No gaps were found
between silt curtains at Portion X.
2.The stagnant water was
removed at S8.
3.The water source of the
drain pipe was labelled at S11.
4.Sand bags was provided
along seafront at S7 to avoid dropping of silt and debris into the sea.
5.The rubbish was removed
at S11.
6.Black smoke no longer
observed from a pilling rig at S15.
7.The chemicals were
removed from the site and an additional drip tray was provided at S15.
8.Stagnant water was
removed at S15.
9.The chemical container
was removed at S15.
3 Mar 2016
3 Mar 2016
1.No drip tray was
provided for chemicals at HMA.
2.A container was
full of general refuse at HMA and general refuse was accumulated in an open
space at N26.
3.Stagnant water was
observed inside a drip tray at HMA.
4.An oil stain was observed at N26.
5.Stagnant water was found inside blocked U
channels at N26.
6.Scum was observed at PR10.
1.The chemicals were
removed from site and a drip tray was provided at HMA.
2.The accumulated
waste at HMA and at N26 was removed.
3.The stagnant water
inside the drip tray at HMA was removed.
4.The oil stain at
N26 was cleaned up.
5.The stagnant water
inside the blocked U channel was removed.
6.The scum at PR10 was removed.
9 Mar 2016
7.A silt curtain was not properly aligned at
Portion X.
7.The silt curtain at Portion X was aligned
properly.
16 Mar 2016
9 Mar 2016
1.Stagnant water was
observed at A2 Bridge, S7 and S15.
2.A gap was found in
the slit curtains at Portion X and HMA.
3.No proper
protection was provided along the seafront at S7.
4.Accumulated waste
was observed at the open area of S25 and the rubbish bin at WA6 was full of
rubbish.
5.Silt and debris
were found next to a road at S25.
6.No measure was
provided for a public road next to the construction site to prevent surface
runoff to the road at S25.
1.The stagnant water at A2 Bridge, S7 and S15
was removed.
2.The silt curtains at Portion X and HMA were
maintained and aligned properly.
3.Sand bags were provided along seafront at S7
to prevent surface runoff into the sea.
4.The accumulated
waste the open area of S25 and inside the rubbish bin at WA6 was removed.
5.The silt and debris at the road side of S25
was removed.
6.Water barriers together with sand bags were
placed along the construction site next to the public road to prevent runoff
leakage at S25 was provided.
16 Mar 2016
16 Mar 2016
1.Stagnant water was
observed inside a drip tray at N26.
2.Muddy water was
observed at PR10.
3.Concrete truck
washing bay was observed full of water at S7.
4.There were gaps at
earth bund along the seafront at S7.
5.An oil stain was
observed at S11.
6.Accumulated waste
was observed at S11, S16 and N1.
1.The stagnant water
inside the drip tray was removed at N26.
2.No muddy water
discharge was observed at PR10.
3.The wastewater
inside the concrete truck washing bay at S7 was pumped out for proper
treatment.
4.Sand bags was
provided along the seafront at S7 and no gaps were found.
5.The oil stain at
S11 was removed.
6.The accumulated waste at S11, S16 and N1 was
removed.
23 Mar 2016
7.Openings of slit
curtain were found at Portion X.
7.Opening of silt
curtain were closed at Portion X.
29 Mar 2016
23 Mar 2016
1.Slit curtains were
not properly aligned at Portion X.
2.Stagnant water was
observed inside a drip tray at HMA.
3.There were gaps in
earth bund at S7.
4.No drip tray was
provided for chemicals at S7.
5.Rubbish was
observed at N1.
6.Broken sand bags
were observed at S7.
1.The silt curtain at
Portion X was aligned properly.
2.The stagnant water inside the drip tray at HMA was
removed.
3.Proper protection along the seafront at S7 was provided to
avoid dropping of silt and debris into the sea.
4.The chemicals were removed at S7.
5.The rubbish was removed at N1.
6.The broken sand bags were removed at S7.
29 Mar 2016
29 Mar 2016
1.No drip tray was
provided for chemical containers at N20.
2.No label was
provided for oil drums at N26.
3.Stagnant water was
observed at N26.
4.Checklists for
checking of wastewater treatment facilities were not properly signed at N26.
5.Waste accumulation
was observed at N26.
6.No labels was
provided to chemical containers at N26.
7.No drip tray was
provided for a chemical container at N26.
The Contractor was recommended to:
1.Provide drip tray for all chemical containers at N20.
2.Provide proper labels for oil drums at N26.
3.Remove the stagnant water promptly to avoid mosquito
breeding.
4.Sign
the checklist for checking wastewater treatment facilities after inspection
immediately at N26.
5.Remove the accumulated waste from site at N26.
6.Provide labels for the chemical containers at N26.
7.Provide drip tray for all
chemical containers at N26.
Follow-up actions for the observations issued for the last weekly site
inspection of the reporting month will be inspected during the next site
inspections.
7.1.3The Contractor has
rectified most of the observations as identified during environmental site
inspections within the reporting month. Follow-up actions for outstanding
observations will be inspected during the next site inspections.
7.2Advice
on the Solid and Liquid Waste Management Status
7.2.1The Contractor
registered as a chemical waste producer for the Project. Sufficient numbers of
receptacles were available for general refuse collection and sorting.
7.2.2Monthly summary of waste flow table is detailed in Appendix
J.
7.2.3The 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.
7.4.1In response to the
site audit findings, the Contractors have rectified most of theobservations as identified during environmental site
inspections during the reporting month. Follow-up actions for outstanding
observations will be inspected during the next site inspections.
7.4.2A summary of the
Implementation Schedule of Environmental Mitigation Measures (EMIS) is
presented in Appendix M. Most of the
necessary mitigation measures were implemented properly.
7.4.3Regular marine travel route for marine vessels were implemented
properly in accordance to the submitted plan and relevant records were kept
properly.
7.4.4Dolphin Watching Plan was implemented during the reporting month. No
dolphins inside the silt curtain were observed. The relevant records were kept
properly.
7.5.1No Action and
Limit Level exceedances of 1-hr TSP and 24-hr TSP were recorded at AMS5 and
AMS6 during the reporting month.
7.5.2For construction noise, no Action
and Limit Level exceedances were recorded at the monitoring station during the
reporting month.
7.5.3For marine water quality
monitoring, no Action Level and Limit Level exceedances of turbidity
level, dissolved oxygen level and suspended solid level were recorded during
the reporting month.
7.6Summary of Complaints, Notification of Summons and
Successful Prosecution
7.6.1There were no
complaints received during the reporting month. The details of cumulative
statistics of Environmental Complaints are provided in Appendix K.
7.6.2No notification of
summons and prosecution was received during the reporting period.
7.6.3Statistics on
notifications of summons and successful prosecutions are summarized inAppendix N.
9.1.1The construction
phase and EM&A programme of the Contract commenced on 17 October 2012. This is the forty-second Monthly
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 to 31 March 2016.
Air Quality
9.1.2No Action and
Limit Level exceedances of 1-hr TSP and 24-hr TSP were recorded at AMS5 and
AMS6 during the reporting month.
Noise
9.1.3For construction
noise, no Action and Limit Level exceedances were recorded at the monitoring
station during the reporting month.
Water Quality
9.1.4For marine water quality
monitoring, no Action Level and Limit Level exceedances of turbidity
level, dissolved oxygen level and suspended solid level were recorded during
the reporting month.
Dolphin
9.1.5During the March¡¦s
surveys of the Chinese White Dolphin, no adverse impact from the activities of this construction project on Chinese White Dolphins was
noticeable from general observations.
9.1.6Due to monthly variation in dolphin occurrence within the study area, it
would be more appropriate to draw conclusion on whether any impacts on dolphins
have been detected related to the construction activities of this project in
the quarterly EM&A report, where comparison on distribution, group size and
encounter rates of dolphins between the quarterly impact monitoring period (March ¡V May 2016) and
baseline monitoring period (3-month period) will be made.
Mudflat
9.1.7This measurement result was
generally and relatively higher than the baseline measurement at S1, S2, S3 and
S4. The mudflat level is continuously increased.
9.1.8The March 2016 survey results indicate that the impacts
of the HKLR project could not be detected on horseshoe crabs, seagrass and
intertidal soft shore community.
Environmental
Site Inspection and Audit
9.1.9Environmental site inspection was carried out on 3, 9, 16, 23 and 29 March 2016. Recommendations on
remedial actions were given to the Contractors for the deficiencies identified
during the site inspections.
9.1.10There were no complaints
received in relation to the environmental impact during the reporting period.
9.1.11No notification of summons and prosecution was
received during the reporting period.