Executive Summary
The Hong Kong-Zhuhai-Macao
Bridge (HZMB) Hong Kong Link Road (HKLR) serves to connect the HZMB Main Bridge
at the Hong Kong Special Administrative Region (HKSAR) Boundary and the HZMB
Hong Kong Boundary Crossing Facilities (HKBCF) located at the north eastern
waters of the Hong Kong International Airport (HKIA).
The HKLR project has been
separated into two contracts. They are Contract No. HY/2011/03 Hong
Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between Scenic Hill and
Hong Kong Boundary Crossing Facilities (hereafter referred to as the Contract)
and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link
Road-Section between HKSAR Boundary and Scenic Hill.
China State Construction
Engineering (Hong Kong) Ltd. was awarded by Highways Department as the
Contractor to undertake the construction works of Contract No. HY/2011/03. The main works of the Contract include
land tunnel at Scenic Hill, tunnel underneath Airport Road and Airport Express
Line, reclamation and tunnel to the east coast of the Airport Island, at-grade
road connecting to the HKBCF and highway works of the HKBCF within the Airport
Island and in the vicinity of the HKLR reclamation. The Contract is part of the HKLR Project
and HKBCF Project, these projects are considered to be ¡§Designated Projects¡¨,
under Schedule 2 of the Environmental Impact Assessment (EIA) Ordinance (Cap
499) and Environmental Impact Assessment (EIA) Reports (Register No.
AEIAR-144/2009 and AEIAR-145/2009) were prepared for the Project. The current Environmental Permit (EP) EP-352/2009/D
for HKLR and EP-353/2009/I for HKBCF were issued on 22 December 2014 and 17 July
2015, respectively. These documents are available through the EIA Ordinance
Register. The construction phase of Contract
was commenced on 17 October 2012.
BMT Asia Pacific Limited
has been appointed by the Contractor to implement the Environmental Monitoring
& Audit (EM&A) programme for the Contract in accordance with the
Updated EM&A Manual for HKLR (Version 1.0) and will be providing
environmental team services to the Contract.
This is the thirty-sixth Monthly EM&A report for the Contract which summaries the monitoring
results and audit findings of the EM&A programme during the reporting
period from 1 to 30 September 2015.
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
|
2, 8, 14, 18, 24 and 30 September 2015
|
24-hr TSP Monitoring
|
1, 7, 11, 17, 23 and 29 September 2015
|
Noise Monitoring
|
4, 8, 14, 24 and 30 September 2015
|
Water Quality Monitoring
|
2, 4, 7, 9, 11, 14, 16, 18, 21, 23, 25, 28 and 30 September 2015
|
Chinese White Dolphin
Monitoring
|
2, 11, 17 and 29 September 2015
|
Mudflat Monitoring (Sedimentation
Rate)
|
10 September 2015
|
Mudflat Monitoring
(Ecology)
|
5, 6, 10, 12 and 13 September 2015
|
Site Inspection
|
2, 9, 16, 25 and 30
September 2015
|
Due
to bad weather condition on 2 Sep 2015, noise monitoring at NMS5 was
rescheduled from 2 Sep 2015 to 4 Sep 2015.
Due
to boat availability issue, the dolphin monitoring schedule was rescheduled
from 15 Sep 2015 to 17 Sep 2015 and from 21 Sep 2015 to 29 Sep 2015.
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)
|
1
|
0
|
Turbidity level
|
0
|
0
|
Dissolved oxygen level (DO)
|
0
|
0
|
One Action Level exceedances of suspended solid level were recorded
during the reporting month.
Complaint Log
There were no complaints
received in relation to the environmental impacts during the reporting period. However, EPD informed SOR and IEC that there
was an enquiry regarding untreated wastewater discharge on 29 September 2015
via email. An investigation is
being undertaken and investigation report will be sent to EPD for record.
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;
- Band Drains Installation at Portion X;
- Excavation and Lateral Support Works at Scenic Hill Tunnel (Cut
& Cover Tunnel) at Portion X;
- Laying Blinding Layer for Tunnel Box Structure 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
- Socket H-Piling work at Scenic Hill Tunnel (Cut & Cover Tunnel)
at Portion X;
- Construction of Sheet Pile at Scenic Hill Tunnel (Cut & Cover
Tunnel) 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;
- Socket H-Piling Works for HKBCF to Airport Tunnel East (Cut
&Cover Tunnel) at Portion X;
- Pipe Piling Works for HKBCF to Airport Tunnel East (Cut &Cover
Tunnel) at Portion X;
- Works 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;
- Canopy Pipe Drilling / Mined Tunnel Excavation / Box Jacking
underneath Airport Road and Airport Express Line;
- Excavation and Lateral Support Works at shaft 3 extension north
shaft & south shaft at Kwo Lo Wan Road;
- Excavation and Lateral Support Works for HKBCF to Airport Tunnel
West (Cut & Cover Tunnel) at Airport Road;
- Utility Culvert Excavation at Portion Y;
- Highway Operation and Maintenance Area Building Foundation &
Sub-structure Works at Portion Y;
- Excavation for Scenic Hill Tunnel at West Portal; and
- Ventilation Building Foundation and
Superstructure Works at West Portal.
1.1.2
The HKLR project has been separated
into two contracts. They are Contract No. HY/2011/03 Hong
Kong-Zhuhai-Macao Bridge Hong Kong Link Road-Section between Scenic Hill and
Hong Kong Boundary Crossing Facilities (hereafter referred to as the Contract)
and Contract No. HY/2011/09 Hong Kong-Zhuhai-Macao Bridge Hong Kong Link
Road-Section between HKSAR Boundary and Scenic Hill.
1.1.3
China State Construction
Engineering (Hong Kong) Ltd. was awarded by Highways Department (HyD) as
the Contractor to undertake the construction works of Contract No.
HY/2011/03. The Contract is part of the HKLR Project and HKBCF Project, these
projects are considered to be ¡§Designated Projects¡¨, under Schedule 2 of the
Environmental Impact Assessment (EIA) Ordinance (Cap 499) and Environmental
Impact Assessment (EIA) Reports (Register No. AEIAR-144/2009 and
AEIAR-145/2009) were prepared for the Project. The current Environmental Permit (EP)
EP-352/2009/D for HKLR and EP-353/2009/I for HKBCF were issued on 22 December
2014 and 17 July 2015, 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.
1.1.4
The Contract
includes the following key aspects:
¡P
New reclamation along
the east coast of the approximately 23 hectares.
¡P
Tunnel 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.
¡P
An 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.
¡P
An 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.
¡P
Road 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.
¡P
A 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.
¡P
Associated 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.
1.1.5
This is the thirty-sixth 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 30 September 2015.
1.1.6 BMT Asia Pacific Limited has been
appointed by the Contractor to implement the EM&A programme
for the Contract in accordance with the Updated EM&A Manual for HKLR
(Version 1.0) for HKLR and will be providing environmental team services to the
Contract. 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.
1.2.1 The 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.
Table
1.1 Contact
Information of Key Personnel
Party
|
Position
|
Name
|
Telephone
|
Fax
|
Supervising Officer¡¦s Representative
(Ove Arup & Partners Hong Kong Limited)
|
(Chief Resident Engineer,
CRE)
|
Robert Antony Evans
|
3968 0801
|
2109 1882
|
Environmental Project Office / Independent
Environmental Checker
(Ramboll Environ Hong Kong Limited)
|
Environmental Project Office Leader
|
Y. H. Hui
|
3465 2888
|
3465 2899
|
Independent Environmental Checker
|
Antony Wong
|
3465 2888
|
3465 2899
|
Contractor
(China State Construction Engineering (Hong Kong) Ltd)
|
Project Manager
|
S. Y. Tse
|
3968 7002
|
2109 2588
|
Environmental Officer
|
Federick Wong
|
3968 7117
|
2109 2588
|
Environmental Team
(BMT Asia Pacific)
|
Environmental Team Leader
|
Claudine Lee
|
2241 9847
|
2815 3377
|
24 hours
complaint hotline
|
---
|
---
|
5699 5730
|
---
|
1.3
Construction
Programme
1.3.1 A
copy of the Contractor¡¦s construction programme is
provided in Appendix B.
1.4
Construction Works Undertaken During the
Reporting Month
1.4.1 A
summary of the construction activities undertaken during this reporting month
is shown in Table 1.2.
Table 1.2 Construction
Activities During Reporting Month
Description
of Activities
|
Site Area
|
Dismantling/trimming of temporary 40mm stone
platform for construction of seawall
|
Portion X
|
Filling works behind stone platform
|
Portion X
|
Construction of seawall
|
Portion X
|
Loading and unloading of filling materials
|
Portion X
|
Band drains installation
|
Portion X
|
Excavation and lateral support works for Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Socket H-Piling work for Scenic Hill Tunnel (Cut
& Cover Tunnel)
|
Portion X
|
Laying blinding layer for tunnel box structure at
Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Construction of
Sheet Pile
at Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Construction of tunnel box structure at Scenic Hill
Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Pipe piling works for HKBCF to Airport Tunnel East
(Cut & Cover Tunnel)
|
Portion X
|
Excavation for HKBCF to Airport Tunnel
|
Portion X
|
Excavation for Scenic Hill Tunnel
|
West Portal
|
Ventilation building
foundation and superstructure works
|
West Portal
|
Works for diversion of Airport Road
|
Airport Road
|
Utilities detection
|
Airport Road/ Airport Express Line/ East Coast Road
|
Establishment of Site Access
|
Airport Road/ Airport Express Line/ East Coast Road
|
Canopy pipe drilling underneath Airport Express Line
|
Airport Express Line
|
Excavation and lateral support works at shaft 3
extension north shaft & south shaft
|
Kwo Lo Wan
Road
|
Excavation and Lateral
Support Works for HKBCF to Airport Tunnel West (Cut & Cover Tunnel)
|
Airport Road
|
Utility culvert excavation
|
Portion Y
|
Highway Operation and
Maintenance Area Building foundation & sub-structure works
|
Portion Y
|
2.1
Monitoring
Requirements
2.1.1 In 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.
Table 2.1 Action
and Limit Levels for 1-hour TSP
Monitoring Station
|
Action Level, µg/m3
|
Limit Level, µg/m3
|
AMS 5 ¡V Ma Wan Chung Village (Tung Chung)
|
352
|
500
|
AMS 6 ¡V Dragonair / CNAC (Group) Building
(HKIA)
|
360
|
Table 2.2 Action
and Limit Levels for 24-hour TSP
Monitoring Station
|
Action Level, µg/m3
|
Limit Level, µg/m3
|
AMS 5 ¡V Ma Wan Chung Village (Tung Chung)
|
164
|
260
|
AMS 6 ¡V Dragonair / CNAC (Group) Building
(HKIA)
|
173
|
260
|
2.2.1
24-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 2.3 Air
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)
|
2.3.1
Monitoring locations AMS5
and AMS6 were set up at the proposed locations in accordance
with Contract Specific EM&A Manual.
2.3.2
Figure 2.1 shows the locations of monitoring stations. Table 2.4 describes the details of the
monitoring stations.
Table 2.4 Locations
of Impact Air Quality Monitoring Stations
Monitoring
Station
|
Location
|
AMS5
|
Ma Wan Chung Village (Tung Chung)
|
AMS6
|
Dragonair / CNAC (Group) Building (HKIA)
|
2.4.1
Table 2.5 summarizes the monitoring parameters, frequency and
duration of impact TSP monitoring.
Table 2.5 Air
Quality Monitoring Parameters, Frequency and Duration
Parameter
|
Frequency
and Duration
|
1-hour TSP
|
Three times every 6 days while the highest
dust impact was expected
|
24-hour TSP
|
Once every 6 days
|
2.5.1
24-hour TSP Monitoring
(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.
2.5.2
1-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.
2.6.1
The schedule for air quality monitoring October 2015 is provided in Appendix
D.
2.7.1
The 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 2.6 Summary
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
|
95
|
58 - 151
|
352
|
500
|
AMS6
|
97
|
66 - 138
|
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
|
36
|
18 - 77
|
164
|
260
|
AMS6
|
61
|
34 - 119
|
173
|
260
|
2.7.2
No Action and
Limit Level exceedances of 1-hour TSP and 24-hour TSP were recorded at AMS5 and
AMS6 during the reporting month.
2.7.3
The event action plan is
annexed in Appendix F.
2.7.4
The wind data obtained from the on-site weather station during the reporting month is shown in Appendix G.
3.1.1
In 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
3.1 Action
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)
|
3.2.1
Noise 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
|
3.3.1
Monitoring location NMS5 was set up at the
proposed locations in accordance with Contract Specific EM&A Manual.
3.3.2
Figure 2.1 shows the locations
of monitoring stations. Table 3.3 describes the details of the monitoring
stations.
Table
3.3 Locations
of Impact Noise Monitoring Stations
Monitoring Station
|
Location
|
NMS5
|
Ma Wan Chung Village (Ma
Wan Chung Resident Association) (Tung Chung)
|
3.4.1 Table 3.4 summarizes the
monitoring parameters, frequency and duration of impact noise monitoring.
Table 3.4
Noise
Monitoring Parameters, Frequency and Duration
Parameter
|
Frequency and Duration
|
30-mins measurement at
each monitoring station between 0700 and 1900 on normal weekdays (Monday to
Saturday). Leq, L10 and L90
would be recorded.
|
At least once per week
|
3.5.1 Monitoring Procedure
(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.
3.5.2 Maintenance 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.
3.6.1 The schedule for
construction noise monitoring in October 2015 is provided in Appendix D.
3.7.1
The monitoring results for construction noise are
summarized in Table 3.5 and the
monitoring results and relevant graphical plots are provided in Appendix E.
Table 3.5 Summary
of Construction Noise Monitoring Results During the Reporting Month
Monitoring Station
|
Average Leq (30 mins), dB(A)
|
Range of Leq (30 mins), dB(A)
|
Limit Level Leq (30 mins), dB(A)
|
NMS5
|
56
|
55 ¡V 58
|
75
|
*A correction factor of +3dB(A) from free
field to facade measurement was included.
3.7.2
There were no Action and Limit Level exceedances for noise during
daytime on normal weekdays of the reporting month.
3.7.3
Major noise sources during the noise monitoring
included construction activities of the Contract, nearby traffic and insect noise.
3.7.4 The event action
plan is annexed in Appendix F.
4
Water Quality Monitoring
4.1.1 Impact 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.
4.1.2 The
original and revised Action Level and Limit Level for turbidity and suspended
solid are shown in Table 4.1.
Table
4.1 Action
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.
4.2.1
Table 4.2 summarises the
equipment used in the impact water quality monitoring programme.
Table
4.2 Water
Quality Monitoring Equipment
Equipment
|
Brand and Model
|
DO and Temperature Meter,
Salinity Meter, Turbidimeter and pH Meter
|
YSI Model 6820 V2-M, 650
|
Positioning Equipment
|
DGPS ¡V KODEN :
KGP913MkII, KBG3
|
Water Depth Detector
|
Layin Associates: SM-5 &
SM5A
|
Water Sampler
|
Wildlife Supply Company :
5487-10
|
4.3.1
Table 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
4.3 Impact
Water Quality Monitoring Parameters and Frequency
Monitoring Stations
|
Parameter, unit
|
Frequency
|
No. of depth
|
Impact Stations:
IS5, IS(Mf)6, IS7, IS8, IS(Mf)9 & IS10,
Control/Far Field
Stations:
CS2 & CS(Mf)5,
Sensitive Receiver Stations:
SR3, SR4, SR5, SR10A & SR10B
|
¡P
Depth, m
¡P
Temperature, oC
¡P
Salinity, ppt
¡P
Dissolved Oxygen
(DO), mg/L
¡P
DO Saturation, %
¡P
Turbidity, NTU
¡P
pH
¡P Suspended Solids (SS), mg/L
|
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).
|
4.4.1
In 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.
4.4.2 The 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
|
4.5
Monitoring
Methodology
4.5.1
Instrumentation
(a) The
in-situ water quality parameters including dissolved oxygen, temperature,
salinity and turbidity, pH were measured by multi-parameter meters.
4.5.2
Operating/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 4.5 Laboratory
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.
4.5.3
Maintenance 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.
4.6.1
The schedule for impact water quality monitoring in October
2015 is provided in Appendix D.
4.7.1
Impact 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 in Appendix E.
4.7.2 Number of
exceedances recorded during the reporting month at each impact station are
summarised in Table 4.6.
Table 4.6 Summary
of Water Quality Exceedances
Station
|
Exceedance Level
|
DO
(S&M)
|
DO
(Bottom)
|
Turbidity
|
SS
|
Total number of exceedances
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
Ebb
|
Flood
|
IS5
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS(Mf)6
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS7
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS8
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS(Mf)9
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
IS10
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR3
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR4
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
11 Sep 2015
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR5
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR10A
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
SR10B
|
Action Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Limit Level
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
--
|
0
|
0
|
Total
|
Action
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
1**
|
Limit
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0**
|
Notes:
S: Surface;
M: Mid-depth;
** The
total number of
exceedances
4.7.1 For marine
water quality monitoring, one Action Level exceedances of suspended solid
level were recorded during
the reporting month. No Limit Level exceedance of suspended solid level was recorded. No
Action Level/ Limit Level exceedance of turbidity
level and dissolved oxygen level were recorded during the reporting month.
4.7.2
The
construction activities on 11 September 2015 were carried out within silt
curtain as recommended in the EIA Report. There were no specific activities recorded during the monitoring period that would cause any significant impacts on the
monitoring results. The exceedance of suspended solid level was considered to be
attributed to other external factors, rather than the contract works.
Therefore, the exceedance was
considered as non-contract related. Record of ¡§Notification of Environmental Quality Limit Exceedances¡¨ is
provided in Appendix N.
4.7.1
Water
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.
4.7.2
The
event action plan is annexed in Appendix
F.
5.1.1 Impact dolphin
monitoring is required to be conducted
by a qualified dolphin specialist team to evaluate whether there have been any effects on the dolphins.
5.1.2
The Action Level and Limit Level for dolphin monitoring are shown in Table 5.1.
Table
5.1 Action
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.
5.1.3
The 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.
Vessel-based Line-transect Survey
5.2.1
According 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 5.2 Co-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.
5.2.2 The
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 16 years of marine mammal monitoring
surveys in Hong Kong developed by HKCRP (see Hung 2012, 2013). 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.
5.2.3 Two
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.
5.2.4 During
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).
5.2.5 Data
including time, position and vessel speed were also automatically and
continuously logged by handheld GPS throughout the entire survey for subsequent
review.
5.2.6 When
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.
5.2.7 Survey
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.
5.2.8 Encounter
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
5.2.9 When 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.
5.2.10 A
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.
5.2.11 All
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.
5.2.12 Chinese
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).
5.2.13 All
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.
Vessel-based Line-transect Survey
5.3.1 During the month of September 2015, two sets of systematic line-transect
vessel surveys were conducted on 2nd, 11th, 17th and 29th to 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.
5.3.2 From these surveys, a total of 303.46
km of survey effort was collected, with 99.0% 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 areas, 115.34
km and 188.12
km of survey effort were collected from
NEL and NWL survey areas respectively.
Moreover,
the total survey effort conducted on primary lines was
221.51 km, while the effort on secondary lines
was 81.95
km.
5.3.3 During the two sets of monitoring surveys in
September 2015, seven groups
of 54
Chinese White Dolphins were sighted. (Annex II of Appendix H). All seven
dolphin sightings were made in NWL, while none was sighted at all in NEL.
5.3.4 During September¡¦s surveys, all
seven dolphin sightings
were made on primary lines during
on-effort search.
One of the dolphin groups was associated with an
operating purse-seiner
near Lung Kwu Chau.
5.3.5 Distribution of these dolphin sightings made in September 2015 is shown in Figure
6 of Appendix H. Six
of the seven dolphin groups were clustered near Lung Kwu
Chau or to the north of the island, while another sighting was made to the west
of Sha Chau (Figure 6 of Appendix H).
5.3.6 Notably none of the dolphin sightings were located
in the proximity of the HKLR03 and HKBCF reclamation sites, as well as the
HKLR09 and TMCLKL alignments (Figure 6 of Appendix H).
5.3.7 During
the September¡¦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.
5.3.8
The average group size of Chinese White Dolphins in September 2015 was
only 7.7 individuals per group, which was exceptionally high when compared to
previous months of monitoring surveys.
Among the seven groups, five of them were composed of 4-8 dolphins,
while there were two large groups with 12 dolphins respectively.
Table 5.3 Individual Survey Event Encounter Rates
|
Encounter
rate (STG)
(no. of on-effort dolphin sightings per 100
km of survey effort)
|
Encounter
rate (ANI)
(no. of dolphins from all on-effort
sightings per 100 km of survey
effort)
|
Primary Lines Only
|
Primary Lines Only
|
NEL
|
Set
1: September 2nd / 11th
|
0.0
|
0.0
|
Set
2: September 17th / 29th
|
0.0
|
0.0
|
NWL
|
Set
1: September 2nd / 11th
|
5.5
|
52.0
|
Set
2: September 17th / 29th
|
4.0
|
21.4
|
Remarks:
1. Dolphin Encounter Rates Deduced from the Two
Sets of Surveys (Two Surveys in Each Set) in September 2015 in Northeast (NEL) and Northwest Lantau
(NWL).
Table 5.4 Monthly
Average Encounter Rates
|
Encounter
rate (STG)
(no. of on-effort dolphin sightings per 100
km of survey effort)
|
Encounter rate (ANI)
(no.
of dolphins from all on-effort sightings per 100 km of survey effort)
|
Primary Lines Only
|
Both Primary and Secondary Lines
|
Primary Lines Only
|
Both Primary and Secondary Lines
|
Northeast
Lantau
|
0.0
|
0.0
|
0.0
|
0.0
|
Northwest
Lantau
|
4.7
|
3.7
|
36.5
|
28.7
|
Remarks:
1.
Monthly Average Dolphin Encounter Rates (Sightings Per 100 km of
Survey Effort) from All Four Surveys Conducted in September 2015 on Primary Lines only as well as Both
Primary Lines and Secondary Lines in Northeast (NEL) and Northwest Lantau
(NWL).
Photo-identification Work
5.3.9
Twenty-three individual dolphins were sighted 33 times during
September¡¦s surveys (Annex III and IV of Appendix H). The majority of individuals were
sighted only once during the monitoring month, but there were also six
individuals being sighted twice and two individuals being sighted thrice.
5.3.10
Notably, three individuals (NL202, NL233
and NL297) were accompanied with calves during their re-sightings.
Conclusion
5.3.11
During this month of dolphin
monitoring, no adverse impact from the activities of this construction project
on Chinese White Dolphins was noticeable from general observations.
5.3.12 Due 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 (September ¡V November 2015)
and baseline monitoring period (3-month period) will be made.
5.4.1
Buckland, 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.
5.4.2
Hung, S. K. 2012. Monitoring of Marine Mammals in Hong
Kong waters: final report (2011-12).
An unpublished report submitted to the Agriculture, Fisheries and
Conservation Department, 171 pp.
5.4.3
Hung, S. K. 2013. Monitoring of Marine Mammals in Hong Kong waters: final report (2012-13). An unpublished report submitted to the
Agriculture, Fisheries and Conservation Department, 168 pp.
5.4.4
Jefferson, T. A. 2000. Population biology of the Indo-Pacific
hump-backed dolphin in Hong Kong waters.
Wildlife Monographs 144:1-65.
Methodology
6.1.1
To 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.
6.1.2
Measurements 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 6.1 Reference
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
|
6.1.3
The 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
6.1.4
Four monitoring stations were established based on the
site conditions for the sedimentation monitoring and are shown in Figure 6.1.
Monitoring Results
6.1.5
The baseline sedimentation rate monitoring was in
September 2012 and impact sedimentation rate monitoring was undertaken on 14
June 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 6.2 Measured
Mudflat Surface Level Results
|
Baseline
Monitoring (September 2012)
|
Impact
Monitoring (September 2015)
|
Monitoring Station
|
Easting (m)
|
Northing (m)
|
Surface Level
(mPD)
|
Easting (m)
|
Northing (m)
|
Surface Level
(mPD)
|
S1
|
810291.160
|
816678.727
|
0.950
|
810291.167
|
816678.723
|
1.061
|
S2
|
810958.272
|
815831.531
|
0.864
|
810958.278
|
815831.542
|
0.960
|
S3
|
810716.585
|
815953.308
|
1.341
|
810716.595
|
815953.340
|
1.466
|
S4
|
811221.433
|
816151.381
|
0.931
|
811221.414
|
816151.336
|
1.004
|
Table 6.3 Comparison
of measurement
|
Comparison
of measurement
|
Remarks and Recommendation
|
Monitoring
Station
|
Easting
(m)
|
Northing
(m)
|
Surface
Level
(mPD)
|
S1
|
0.007
|
-0.004
|
0.111
|
Level continuously
increased
|
S2
|
0.006
|
0.011
|
0.096
|
Level continuously increased
|
S3
|
0.010
|
0.032
|
0.125
|
Level continuously
increased
|
S4
|
-0.019
|
-0.045
|
0.073
|
Level continuously
increased
|
6.1.6
This measurement result was generally and relatively higher than the
baseline measurement at S1, S2, S3 and S4. The mudflat level is continuously
increased.
6.2.1
The mudflat monitoring covered water quality
monitoring data. Reference was made
to the water quality monitoring data of the representative water quality
monitoring station (i.e. SR3) as in the EM&A Manual. The water quality monitoring location
(SR3) is shown in Figure 2.1.
6.2.2
Impact water quality monitoring in San Tau (monitoring
station SR3) was conducted in June 2015.
The monitoring parameters included dissolved oxygen (DO), turbidity and
suspended solids (SS).
6.2.3
The Impact monitoring results for SR3 were extracted
and summarised below:
Table 6.4 Impact
Water Quality Monitoring Results (Depth Average)
Date
|
Mid Ebb Tide
|
Mid Flood Tide
|
DO (mg/L)
|
Turbidity (NTU)
|
SS (mg/L)
|
DO (mg/L)
|
Turbidity (NTU)
|
SS (mg/L)
|
2-Sep-15
|
5.69
|
20.40
|
8.30
|
5.46
|
15.85
|
13.50
|
4-Sep-15
|
6.27
|
7.55
|
7.35
|
6.22
|
4.40
|
4.60
|
7-Sep-15
|
6.32
|
3.75
|
3.30
|
6.43
|
4.75
|
5.80
|
9-Sep-15
|
6.89
|
4.65
|
2.95
|
7.75
|
4.80
|
4.10
|
11-Sep-15
|
6.53
|
5.95
|
5.35
|
9.00
|
7.20
|
6.80
|
14-Sep-15
|
5.82
|
6.75
|
6.50
|
5.74
|
5.35
|
7.00
|
16-Sep-15
|
5.86
|
10.70
|
11.90
|
5.64
|
7.50
|
7.70
|
18-Sep-15
|
5.82
|
8.50
|
7.50
|
5.71
|
6.70
|
6.20
|
21-Sep-15
|
6.07
|
6.30
|
5.30
|
6.58
|
3.80
|
2.70
|
23-Sep-15
|
6.15
|
3.80
|
2.45
|
7.39
|
3.30
|
2.60
|
25-Sep-15
|
6.63
|
5.20
|
5.90
|
8.23
|
10.05
|
5.20
|
28-Sep-15
|
5.27
|
7.65
|
7.90
|
6.04
|
8.05
|
8.55
|
30-Sep-15
|
5.64
|
17.15
|
13.75
|
5.47
|
12.45
|
16.00
|
Average
|
6.07
|
8.33
|
6.80
|
6.59
|
7.25
|
6.98
|
Sampling Zone
6.3.1
In order to collect baseline
information of mudflats in the study site, the study site was divided into three sampling zones
(labeled as TC1, TC2, TC3) in Tung Chung Bay
and one zone in San Tau (labeled as ST) (Figure 2.1 of Appendix I). The
horizontal length of sampling zones TC1, TC2, TC3 and ST
were about 250 m, 300 m, 300 m and 250 m, respectively. Survey of horseshoe
crabs, seagrass beds and intertidal communities were conducted in every
sampling zone. The present survey was conducted in September 2015 (totally 5
sampling days between 5th and 13th September 2015).
Horseshoe Crabs
6.3.2
Active search method was conducted for horseshoe crab monitoring by two experienced surveyors at every sampling zone. During the search period, any accessible and potential area would
be investigated for any horseshoe crab individuals within 2-3 hours in low tide period (tidal level
below 1.2 m above Chart Datum (C.D.)). Once a horseshoe crab individual was found, the species was identified
referencing to Li (2008). The prosomal width, inhabiting substratum and respective GPS coordinate were recorded. A photographic
record was taken for future investigation. Any
grouping behavior of individuals, if found, was recorded. The horseshoe crab surveys were
conducted on 6th (for TC1), 10th (for TC3 and ST) and 12th
(for TC2) September 2015. During the survey period, the weather was hot and sunny
in TC1, TC3 and ST while it was rainy in TC2.
Seagrass Beds
6.3.3
Active search method was conducted for seagrass
bed monitoring by two experienced surveyors at every sampling zone. During the search period, any accessible and potential area would
be investigated for any seagrass beds within 2-3 hours in low tide period. Once seagrass bed was found, the species, estimated area, estimated coverage percentage and respective GPS coordinate were recorded. A photographic
record was taken for future investigation. The seagrass beds surveys were
conducted on 6th (for TC1), 10th (for TC3 and ST) and 12th
(for TC2) September 2015. During the survey period, the weather was hot and sunny
in TC1, TC3 and ST while it was rainy in TC2.
Intertidal Soft Shore Communities
6.3.4 The intertidal soft shore
community surveys were conducted in low tide period on 5th (for ST),
6th (for TC1), 12th (for TC2) and 13th September
2015 (for TC3). At each sampling zone, three 100 m horizontal transects were laid
at high tidal level (H: 2.0 m above C.D.), mid tidal level (M: 1.5 m above C.D.) and
low tidal level (L: 1.0 m above C.D.). Along every horizontal transect, ten random quadrats
(0.5 m x 0.5m) were placed.
6.3.5 Inside a quadrat, any visible epifauna
were collected and were in-situ identified to the
lowest practical taxonomical resolution. Whenever possible a hand core sample (10 cm internal diameter ´ 20 cm depth) of sediments was collected
in the quadrat. The core sample was gently washed through a sieve of mesh size
2.0 mm in-situ. Any visible infauna
were collected and identified. Finally the top 5 cm surface sediments were dug for visible infauna in the quadrat regardless of hand core sample was
taken.
6.3.6 All collected fauna were released after recording except some tiny
individuals that are too small to be identified on site. These
tiny individuals were taken to laboratory for identification under dissecting microscope.
6.3.7 The taxonomic classification was conducted in accordance to the
following references: Polychaetes: Fauchald (1977),
Yang and Sun (1988); Arthropods: Dai and Yang (1991), Dong (1991); Mollusks: Chan and Caley (2003),
Qi (2004).
Data Analysis
6.3.8
Data collected from direct search and core sampling
was pooled in every quadrat for data analysis. Shannon-Weaver Diversity Index
(H¡¦) and Pielou¡¦s Species Evenness (J) were
calculated for every quadrat using the formulae below,
H¡¦= -£U ( Ni / N ) ln ( Ni / N )
(Shannon and Weaver, 1963)
J = H¡¦ / ln
S, (Pielou, 1966)
where S is the total number of species in the sample, N is
the total number of individuals, and Ni is the number of individuals of the ith species.
6.4.1
In 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 6.5 Event
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 are
significantly 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;
Implement the agreed measures.
|
Notes:
ET ¡V Environmental Team
IEC ¡V Independent Environmental Checker
SO ¡V Supervising Officer
Horseshoe Crabs
6.5.1
In general, two species of horseshoe
crab Carcinoscorpius rotundicauda
(total 196 ind.) and Tachypleus tridentatus (total 10 ind.) were recorded in the survey area. Individuals were
mainly found on fine sand while few were found on soft mud. The group size varied varied from 2 to 26 individuals for
every sight record. Although less number of Tachypleus tridentatus was recorded, the average body size was larger than that of Carcinoscorpius rotundicauda. Photo records were shown in Figure 3.1 of Appendix I while the complete
records of horseshoe crab survey in every sampling zone were shown in Annex II of Appendix I.
6.5.2
One big individual of Carcinoscorpius rotundicauda was found trapped in a trash
fish net (Figure 3.1 of Appendix I)
on ST shore (GPS coordinate: 22¢X 17.385' N, 113¢X 55.460' E). Its prosomal width
reached 130.77 mm. After photo recording, it was released to water. This big
individual should have had migrated to sub-tidal habitat. It might forage on
intertidal habitat occasionally during high tide period. Since intertidal soft
shore was no longer a nursery ground for this individual, its record was
excluded from the data analysis. It was to avoid mixing up with juvenile population living on soft shore.
6.5.3
Table 3.1 of Appendix I summarizes the survey
results of horseshoe crab in present survey. For Carcinoscorpius rotundicauda, it could be found in all sampling zones while more individuals were
recorded in TC3 and ST (TC1: 41 ind., TC2: 4 ind., TC3: 70 ind., ST: 81 ind.). The search record was 10.3 ind. hr-1 person-1, 1.0 ind. hr-1 person-1, 11.7 ind. hr-1 person-1,
13.5 ind. hr-1
person-1 in TC1, TC2, TC3 and ST respectively. The size of individuals was
similar among TC1 (mean prosomal width:
39.58 mm), TC2 (36.20 mm) and ST (37.03mm) while that of TC3 was smaller (27.27
mm).
6.5.4
For Tachypleus tridentatus, it could be found in TC3 (1 ind.) and ST (9 ind.) only. The search records were 0.2 ind. hr-1
person-1 and 1.5 ind. hr-1 person-1 in TC3 and ST respectively. The
mean prosomal
width of TC3 (53.90 mm) was
larger than that of ST (48.50mm).
6.5.5
In the previous survey of March 2015, there was one important finding
that a mating pair of Carcinoscorpius rotundicauda was found in ST (prosomal width: male 155.1 mm, female 138.2 mm) (Figure 3.2 of Appendix I). It indicated the importance of ST as a breeding ground of horseshoe
crab. Moreover, two moults of Carcinoscorpius rotundicauda were found in TC1 with similar prosomal width 130-140 mm (Figure 3.2 of Appendix 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.
6.5.6
No marked individual of horseshoe crab was recorded in present survey.
Some marked individuals were found in previous surveys conducted in September
2013, March 2014 and September 2014. All of them were released through a
conservation programme conducted by Prof. Paul Shin (Department
of Biology and Chemistry, The City University of Hong Kong (CityU)).
It was a re-introduction trial of artificial bred horseshoe crab juvenile at
selected sites. So that the horseshoe crabs population might be restored in the
natural habitat. Through a personal conversation with Prof. Shin, about 100
individuals were released in the sampling zone ST on 20 June 2013. All of them
were marked with color tape and internal chip detected by specific chip sensor.
There should be second round of release between June and September 2014 since
new marked individuals were found in the survey of September 2014.
6.5.7
The artificial bred individuals, if found,
would be excluded from the results of present monitoring programme
in order to reflect the changes of natural population. However, the mark on
their prosoma might have been detached during moulting
after a certain period of release. The artificially released individuals were
no longer distinguishable from the natural population without the specific chip
sensor. The survey data collected would possibly cover both natural population
and artificially bred individuals.
Population difference among
the sampling zones
6.5.8
Figures 3.3 and 3.4
of Appendix I show the changes of number of individuals, mean
prosomal width and search record of horseshoe crabs Carcinoscorpius rotundicauda
and Tachypleus tridentatus respectively in every sampling
zone along the sampling months. In general, higher search records (i.e. number of individuals)
of both species were always found in ST followed by TC3 from September 2012 to
September 2014. Then the search record in TC3 was even higher than that in ST
from March 2015 to June 2015. In this sampling month (Sep. 2015), highest
search record was found in ST again. For TC1, the search record was at low to
medium level and fluctuated slightly along the sampling months. In
contrast, much lower search record was found in TC2 (2 ind.
in September 2013, 1 ind. in March, June, September.
2014, March and June 2015, 4 ind. in September. 2015).
For spatial difference of horseshoe crab size, larger individuals were usually
found in ST while smaller individuals were usually found in TC3.
6.5.9
Throughout 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
6.5.10
Throughout 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 Carcinoscorpius rotundicauda and 8 individuals of Tachypleus tridentatus 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-1 and 0.00 ind. hr-1 person-1 in wet season and dry season respectively (details see Li, 2008). After
the dry season, the search record increased with the warmer climate.
6.5.11
Between the sampling months September 2012 and December 2013, Carcinoscorpius rotundicauda was
a less common species relative to Tachypleus tridentatus. Only 4 individuals were ever
recorded in ST in December 2012. This species had ever been believed of very
low density in ST hence the encounter rate was very low. Since March. 2014, it was
found in all sampling zones with higher abundance in ST. Based on its average
size (mean prosomal width 39.28-49.81 mm), it indicated that breeding and
spawning of this species had occurred about 3 years ago along the coastline of
Tung Chun Wan. However, these individuals were still small while their walking
trails were inconspicuous. Hence there was no search record in previous sampling
months. From March 2014 to September 2015, more individuals were recorded due
to larger size and higher activity.
6.5.12
For Tachypleus tridentatus, sharp increase of
number of individuals was recorded in ST with wet season (from March to September
2013). According to a personal conversation with Prof. Shin (CityU), his monitoring team had recorded similar increase
of horseshoe crab population during wet season. It was believed that the suitable
ambient temperature increased its conspicuousness. However similar pattern was
not recorded during the wet season of 2014. The number of individuals increased
in March and June 2014 followed by a rapid decline in September 2014. Then the
number of individuals showed a general decreasing trend from March. 2014 to June
2015. Apart from natural mortality, migration from nursery soft shore to
subtidal habitat was another possible cause. Since the mean prosomal width of Tachypleus tridentatus continued to grow and reached
about 50 mm since March 2014. Then it varied slightly between 50-65 mm from
September 2014 to September 2015. Most of the individuals might have reached a
suitable size strong enough to forage in sub-tidal habitat.
6.5.13
Since 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
6.5.14
Figure 3.5 of Appendix I shows the changes of prosomal width of Carcinoscorpius rotundicauda and Tachypleus tridentatus in TC3. As mentioned above, Carcinoscorpius rotundicauda was rarely found between September
2012 and December 2013 hence the data were lacking. In March 2014, the major
size (50% of individual
records between upper and lower quartile) ranged 40-60 mm while only few
individuals were found. From March 2014 to September 2015, the size of major population
decreased and more small individuals were recorded after March of every year. It
indicated new rounds of successful breeding and spawning of Carcinoscorpius rotundicauda in
TC3. It matched with the previous mating record in ST in March 2015.
6.5.15
For Tachypleus tridentatus, the major size ranged
20-50 mm while the number of individuals found fluctuated from September 2012
to June 2014. Then a slight but consistent growing trend was observed. The prosomal
width increased from 25-35 mm in September 2014 to 35-65 mm in June 2015. As
mentioned, the large individuals might have reached a suitable size for migrating from the
nursery soft shore to subtidal habitat. It accounted for the declined
population in TC3. In September 2015 (present survey), there was only one
individual recorded in TC3.
Box plot of horseshoe crab populations in ST
6.5.16 Figure 3.6 of Appendix I
shows the changes of
prosomal width of Carcinoscorpius rotundicauda and Tachypleus tridentatus in ST. As mentioned above, Carcinoscorpius rotundicauda was rarely found between September
2012 and December 2013 hence the data were lacking. From Mar. 2014 to Sep.
2015, the size of major population
decreased and more small individuals were recorded after Jun. of every year. It
indicated new rounds of successful breeding and spawning of Carcinoscorpius rotundicauda in
ST. It matched with the previous mating record in ST in Mar. 2015. Because the
newly hatched individuals (prosomal width ~5mm) would take about half year to
grow to a size with conspicuous walking trail.
6.5.17 For Tachypleus tridentatus, a consistent growing
trend was observed for the major population from December 2012 to December 2014
regardless of change of search record. The prosomal width increased from 15-30
mm to 55-70 mm. As mentioned, the large individuals might have reached a
suitable size for migrating from the nursery soft shore to subtidal habitat. From
March to June 2015, the size of major population decreased slightly with
prosomal width 40-60 mm. It further indicated some of order individuals might
have migrated to sub-tidal 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.
6.5.18 As a summary for horseshoe crab
populations in TC3 and ST, there was successful spawning of Carcinoscorpius rotundicauda
from 2014 to 2015. The spawning time should be in spring while the major
spawning month might be different slightly between two zones. There were
consistent, increasing trends of population size in these two sampling zones.
For Tachypleus tridentatus,
small individuals were rarely found TC3 and ST from 2014 to 2015. It was
believed no occurrence of successful spawning. The existing individuals (that
recorded since 2012) grew to a mature size and migrated to sub-tidal habitat.
Hence the number of individuals decreased gradually. It was expected the
population would remain at low level until new round of successful spawning.
Impact of the HKLR project
6.5.19 The present survey was the 12th
survey of the EM&A programme during the
construction period. Based on the results, impact of
the HKLR project could not be detected on horseshoe crabs considering the
factor of natural, seasonal variation. In
case, abnormal phenomenon (e.g. very few numbers of horseshoe crab individuals
in warm weather, large number of dead individuals on the shore)
is observed, it would be reported as soon as possible.
Seagrass Beds
6.5.20 In general, two species of
seagrass Halophila ovalis and Zostera japonica were
recorded in ST only. Both species were found on sandy substratum nearby the seaward side of
mangrove vegetation at 2.0 m above C.D. Two species were found coexisting in
two seagrass beds. 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.
6.5.21 Table 3.2 of Appendix I summarize the results of seagrass beds survey in ST. Four
patches of Halophila ovalis were found while the total seagrass bed area was about 91.4 m2
(average area 22.8 m2). The largest patch was a long strand with
seagrass bed area 32.0 m2 and variable vegetation coverage 10-80%.
Two other patches were smaller strands (17.4 and 26.3 m2) with
variable vegetation coverage 30-60%. Both had co-existing seagrass Zostera japonica. The smallest patch was
about 15.8 m2 with highest percentage coverage 80%. For Zostera japonica, there were two long strands (17.4-26.3 m2) of seagrass beds with
low coverage percentage 10-20%. Both long strands had co-existing seagrass Halophila ovalis. The total seagrass bed area was about 43.7 m2 (average area 21.8 m2).
Temporal
variation of seagrass beds
6.5.22 Figure 3.8 of Appendix I shows the changes of estimated total area of seagrass beds in ST along the sampling months. For Zostera japonica, it was not recorded in the 1st and 2nd surveys
of monitoring programme. Seasonal recruitment of few,
small patches (total seagrass area: 10 m2) was found in March 2013
that grew within the large patch of seagrass Halophila ovalis. Then the patch size increased and merged gradually with the warmer
climate from March to June 2013 (15 m2). However the patch size decreased
sharply and remained similar from September 2013 (4 m2) to March
2014 (3 m2). In June 2014, the patch size increased obviously again
(41 m2) with warmer climate. Similar to previous year, the patch
size decreased again and remained similar September 2014 (2 m2) to
December 2014 (5 m2). From March to June 2015, the patch size
increased sharply again (90.0 m2). It might be due to the
disappearance of the originally dominant seagrass Halophila ovalis resulting in less competition
for substratum and nutrients. In September 2015, the patch size decreased and
was found coexisting with seagrass
Halophila ovalis. In
general, the seagrass bed of Zostera japonica fluctuated in patch size along the sampling months.
6.5.23
For Halophila ovalis, it was recorded as 3-4 medium
to large patches (area 18.9 - 251.7 m2; vegetation coverage 50-80%)
beside the mangrove vegetation at tidal level 2 m above C.D in the September
2012 (First survey). The
total seagrass bed area grew steadily from 332.3 m2 in September
2012 to 727.4 m2 in December 2013. Flowers could be observed in the
largest patch during its flowering period in December 2013. In March 2014, 31 small to
medium patches were newly recorded (variable area 1-72 m2 per patch,
vegetation coverage 40-80% per patch) in lower tidal zone between 1.0 and 1.5 m
above C.D. The total seagrass area increased further to 1350 m2. In
June 2014, these small and medium patches grew and extended to each others. These patches were no longer distinguishable
and were covering a significant mudflat area of ST. It was generally grouped
into 4 large areas (1116 ¡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, Halophila ovalis
could be found in other mud flat area surrounding the single patch. But it was
hardly distinguished into patches due to very low coverage (10-20%) and small
leaves.
6.5.24 In December 2014, all the seagrass patches of Halophila ovalis 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 Halophila ovalis was regarded as a short-lived
and r-strategy seagrass that can
colonize areas in short period but disappears quickly under unfavourable
conditions (Fong, 1998).
Unfavourable
conditions to seagrass Halophila ovalis
6.5.25 Typhoon or strong water current was
suggested as one unfavourable condition to Halophila ovalis (Fong, 1998). As mentioned above, there were two tropical cyclone
records in Hong Kong in September 2014. The strong water current caused by the cyclones
might have given damage to the seagrass beds.
6.5.26 Prolonged light deprivation due to turbid water would be another unfavouable condition. Previous studies reported that Halophila ovalis had little tolerance to light deprivation. During experimental darkness,
seagrass biomass declined rapidly after 3-6 days and seagrass died completely
after 30 days. The rapid death might be due to shortage of available
carbohydrate under limited photosynthesis or accumulation of phytotoxic end
products of anaerobic respiration (details see Longstaff
et al., 1999). Hence the seagrass bed
of this species was susceptible to temporary light deprivation events such as
flooding river runoff (Longstaff and Dennison, 1999).
6.5.27 In 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.
6.5.28
Based on the weather condition and water quality results in ST, the co-occurrence
of cyclone hit and turbid waters in September 2014 might have combined the
adverse effects on Halophila ovalis that leaded to disappearance of this short-lived and r-strategy seagrass species. Fortunately
Halophila ovalis was a fast-growing species (Vermaat et al.,
1995). Previous studies showed that the seagrass bed could be recovered to the
original sizes in 2 months through vegetative propagation after experimental
clearance (Supanwanid, 1996). Moreover it was
reported to recover rapidly in less than 20 days after dugong herbivory (Nakaoka and Aioi, 1999). As
mentioned, the disappeared seagrass in ST in 1995 could recover gradually after
the completion of reclamation works for international airport (Fong, 1998). The
seagrass beds of Halophila ovalis might recolonize the mudflat of ST through seed reproduction as long
as there was no unfavourable condition in the coming
months.
6.5.29
From March to June 2015, 2-3 small
patches of Halophila ovalis were
newly found coinhabiting with another seagrass
species Zostera japonica. But its
total patch area was still very low relative to the previous records. The
recolonization rate was low while cold weather and insufficient sunlight were
possible factors between December 2014 and March 2015. Moreover, it would need
to compete with more abundant seagrass Zostera
japonica for substratum and nutrient. Since Zostera japonica had
extended and had covered the original seagrass bed of Halophila ovalis at certain degree. In September 2015, the total seagrass area of Halophila ovalis had increased rapidly from 6.8 m2
to 91.35 m2. It had recolonized its original patch locations and
covered Zostera japonica. Hence it was expected that the seagrass
bed of Halophila ovalis would
increase continually in the following months.
Impact of the HKLR project
6.5.30
The present survey was the 12th survey of the EM&A programme during the construction period. According to the
results of present survey, there was recolonization of both
seagrass species Halophila ovalis and Zostera japonica in ST. The seagrass patches
were believed in recovery. Hence the negative
impact of HKLR project on the seagrass was not significant. In case, adverse phenomenon (e.g. reduction of seagrass patch size, abnormal change of leave colour) is observed again, it would
be reported as soon as possible.
Intertidal Soft Shore Communities
6.5.31 Table 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:
¡P
In TC1, high percentage of ¡¥Sands¡¦ (70%) was recorded at high tidal
level which was different from previous records (high percentage of ¡¥Gravels
and Boulders¡¦). By direct observation on site, there was no obvious change of
substratum at high tidal level. Hence it was simply due to more random quadrats
laid on sandy substratum in this sampling. High percentage of ¡¥Gravels and
Boulders¡¦ was recorded (80-100%) at mid and low tidal levels.
¡P
In TC2, the substratum distribution was different between tidal levels.
At high tidal level, higher percentage of ¡¥Sands¡¦ (60%) was recorded followed
by ¡¥Soft mud¡¦ (30%). At mid tidal level, higher percentage of ¡¥Sands¡¦ (70%) was
recorded followed by ¡¥Gravels and Boulders¡¦ (30%). At low tidal level, higher
percentage of ¡¥Soft mud¡¦ (60%) was recorded followed by ¡¥Sands¡¦ (40%).
¡P
In TC3, the substratum type was clearly different between high-mid tidal
level and low tidal level. ¡¥Sands¡¦ was the main substratum type (90-100%) at
high and mid tidal levels while ¡¥Gravels and Boulders¡¦ was the main substratum
type (100%) at low tidal level.
¡P
In ST, the substratum type was clearly different between high-mid tidal
level and low tidal level. ¡¥Gravels and Boulders¡¦ (90-100%) was the main
substratum at high and mid tidal levels. At low tidal level, higher percentage
of ¡¥Sands¡¦ (70%) was recorded followed by ¡¥Gravels and Boulders¡¦ (30%).
6.5.32 There 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.
6.5.33 Table 3.4 of Appendix I lists the total abundance, density
and number of taxon of every phylum in this
survey. A total of 12502 individuals were recorded. Mollusca was
significantly the most abundant phylum (total individuals 11994, density 400 ind.
m-2, relative abundance 95.9%). The second abundant phylum
was Arthropoda
(383 ind., 13 ind. m-2,
3.1%). The third and fourth abundant phyla were Annelida (71 ind., 2 ind. m-2, 0.6%) and Sipuncula (23 ind., 1 ind. m-2, 0.2%). Relatively other phyla were very low in abundances (density £1 ind. m-2, relative abundance £0.1%). Moreover, the most diverse phylum was Mollusca (35 taxa)
followed by Arthropoda
(13 taxa) and Annelida (9 taxa). There was 1 taxon recorded only for other phyla. The complete list of collected specimens is shown in Annex V of Appendix I.
6.5.34 Table 3.5 of
Appendix I show the number of individual, relative abundance and density of each
phylum in every sampling zone. The total abundance (2454-4506 ind.) varied among the four sampling zones while the phyla distributions were
similar. In general, Mollusca was the
most dominant phylum (no. of individuals: 2359-4297 ind.; relative abundance 94.9-98.0%; density 315-573 ind. m-2). Other phyla were significantly lower in number of individuals. Arthropoda was the second abundant phylum (35-169 ind.; 1.4-3.8%; 5-23 ind.
m-2). Annelida was the third abundant phylum (32-35 ind.;
0.8-1.1%; 4-5 ind. m-2) in TC2 and TC3. Sipuncula
was the third or fourth abundant phylum (8-9 ind.; 0.3%;
1 ind. m-2) in TC1 and TC2. Cnidaria (sea anemone) was the third abundant phylum (12 ind.; 0.5%; 2 ind.
m-2) in ST. Relatively other phyla were low in abundance among the
four sampling zones (≤ 0.3%).
Dominant species in every sampling zone
6.5.35
Table 3.6 of
Appendix I lists the abundant species (relative abundance >10%) in every sampling zone. In TC1,
gastropod Batillaria multiformis was the
most abundant species (54
ind. m-2, relative abundance 29%) followed
by gastropods Cerithidea djadjariensis
(47 ind. m-2,
25%) and Cerithidea cingulata (38 ind.
m-2, 20%) at high tidal level (major substratum: ¡¥Sands¡¦).
However all abundant species were at low density relative to other sampling
zones. At mid tidal level (major substratum: ¡¥Gravels and Boulders¡¦), the
abundant species were gastropods Monodonta labio (112 ind. m-2, 34%), Batillaria multiformis
(79 ind. m-2, 24%) and rock oyster Saccostrea
cucullata (72 ind. m-2,
22%, attached on boulders) at low-moderate densities.
At low tidal level (major
substratum: ¡¥Gravels and Boulders¡¦), gastropod Monodonta labio (242 ind. m-2, 47%) and rock oyster Saccostrea cucullata (121 ind. m-2,
24%) were abundant at moderate-high densities.
6.5.36
At TC2, gastropod
Cerithidea djadjariensis
(407 ind. m-2,
53%) was the most abundant at high density followed by Cerithidea cingulata (157 ind. m-2,
20%) at high tidal level
(major substratum: ¡¥Sands¡¦). Relative to high tidal level, the density of
every taxon was much lower and similar at mid and low tidal levels. No dominant
species was determined. At mid tidal level (major substratum: ¡¥Sands¡¦), rock oyster Saccostrea cucullata
(76 ind. m-2, 25%, attached on boulders), gastropods
Batillaria zonalis (73 ind. m-2, 24%), Monodonta labio (44 ind. m-2,
15%) and Cerithidea djadjariensis (31 ind. m-2,
10%) were commonly occurring at low density. At low
tidal level (major substratum: ¡¥Soft mud¡¦), Batillaria zonalis (41 ind. m-2, 34%), rock oyster Saccostrea cucullata
(24 ind. m-2, 20%) and
barnacle Balanus amphitrite (19 ind. m-2, 16%, attached
on boulders) were commonly
occurring at low density.
6.5.37 At TC3, the abundant species were
similar with variable densities at high and mid tidal levels (major substratum: ¡¥Sands¡¦). There
were gastropods Cerithidea djadjariensis (146-257 ind. m-2,
25-35%), Batillaria multiformis
(143-256 ind. m-2, 25-35%) and Cerithidea cingulata (128-222 ind. m-2,
18-39%) at moderate
densities. At low
tidal level (major substratum: ¡¥Gravels and Boulders¡¦), gastropod
Monodonta labio (197 ind. m-2, 39%) and rock oyster Saccostrea cucullata (146 ind. m-2,
29%, attached on boulders) were abundant at moderate densities.
Little black mussel Xenostrobus atratus (48 ind. m-2, 10%) was
the third abundant species at low density.
6.5.38 At ST, gastropod Monodonta labio (130-145 ind. m-2, 34-38%) and rock oyster Saccostrea cucullata (80-91 ind. m-2,
21-24%, attached on boulders) were the abundant
species of low-moderate densities at high and mid tidal levels (major
substratum: ¡¥Gravels and Boulders¡¦). Gastropods Batillaria multiformis (76 ind.
m-2, 20%) and Lunella coronata (45 ind.
m-2, 12%) were the third abundant species at high tidal
level and mid tidal level respectively. At
low tidal level (major substratum: ¡¥Sands¡¦), rock oyster Saccostrea cucullata (71 ind.
m-2, 33%) was the most abundant followed by gastropods
Lunella coronata
(41 ind. m-2, 19%) and Euchelus
scaber (30 ind. m-2, 14%). All
three species were at low densities.
6.5.39 In general, there was no consistent zonation
pattern of species distribution observed across all sampling zones and tidal levelsThe species
distribution should be determined by the type of substratum primarily. In general, gastropods Cerithidea djadjariensis (total
number of individuals: 2350 ind., relative abundance 18.8%),
Batillaria multiformis (1757
ind., 14.1%), and Cerithidea cingulata (1561
ind., 12.5%) and Batillaria zonalis (468 ind., 3.7%) were the most commonly occurring species on
sandy and soft mud substrata. Gastropods Monodonta
labio (2249 ind., 18.0%),
Lunella coronata
(408 ind., 3.3%) and rock oyster Saccostrea cucullata
(1930 ind., 15.4%) were commonly occurring species inhabiting
gravel and boulders substratum.
6.5.40 Relative
to the results of previous sampling (June 2015), the densities of gastropod Batillaria multiformis declined sharply in TC1, TC3 and ST. Heat
stress was one possible cause of population decline. According to the online
database of Hong Kong Observatory, there were 14, 13 and 18 days with ¡¥Very
Hot Weather Warning¡¦ in June, July and August 2015 respectively (total 45 days) with mean
monthly ambient temperature 29.1-29.7 ˚C. Moreover majority of low tide period
occurs in day time of summer (especially afternoon) in Hong Kong. The
substratum between mid and high tidal levels would be strongly heated under
direct sunshine with little water splashing. Since this gastropod species usually
inhabits at high and mid tidal levels, high mortality rate would be resulted. Its population was believed to be
restored gradually during dry season.
Biodiversity and abundance of soft shore
communities
6.5.41
Table 3.7 of
Appendix I
shows the mean values of number of species, density, biodiversity index H¡¦ and species evenness J of soft shore communities at every tidal level and in every sampling zone. Among the sampling zones, the mean
species number (10 spp. 0.25 m-2) and mean H¡¦ (1.6) in ST were slightly higher than other sampling zones (mean
species number: 8 spp. 0.25 m-2, H¡¦
1.3-1.4). The mean densities were quite variable among sites. The mean density
of TC3 (601 ind. m-2) was higher than
other sampling zones (327-398 ind. m-2).
However mean J showed no clear
difference among sampling zones (0.6-0.7).
6.5.42 Across 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 tidal level to low tidal level at TC2, TC3 and ST.
At TC1, the mean density at low tidal level was higher than that at high and
mid tidal levels. As mentioned, the variation of mean density should be
determined by the type of substratum primarily.
6.5.43 Figures 3.11 to 3.14 of Appendix I show the temporal changes of mean number of species, mean density,
H¡¦ and J at every tidal level and in every sampling
zone along the sampling months. From Jun. to Sep. 2015, the mean densities
decreased clearly at high tidal level in TC1 and ST. As mentioned, it was due
to higher mortality of dominant gastropod Batillaria multiformis under heat stress of wet season.
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
6.5.44 The present survey was the 12th
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.
6.6.1 Chan, 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.
6.6.2 Dai, A.Y., Yang, S.L., 1991.
Crabs of the China Seas. China Ocean Press. Beijing.
6.6.3 Dong, Y.M., 1991. Fauna of ZheJiang Crustacea. Zhejiang
Science and Technology Publishing House. ZheJiang.
6.6.4 EPD, 1997. Technical Memorandum
on Environmental Impact Assessment Process (1st edition).
Environmental Protection Department, HKSAR Government.
6.6.5 Fauchald, 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.
6.6.6 Fong, 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.
6.6.7 Li, H.Y., 2008. The Conservation
of Horseshoe Crabs in Hong Kong. MPhil Thesis, City University of Hong Kong, pp
277.
6.6.8 Longstaff, B.J., Dennison, W.C., 1999.
Seagrass survival during pulsed turbidity events: the effects of light
deprivation on the seagrasses Halodule pinifolia and Halophila ovalis. Aquatic Botany 65 (1-4), 105-121.
6.6.9 Longstaff, 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 Halophila ovalis (R.
Br.) Hook. Journal of Experimental Marine Biology and Ecology 234 (1), 1-27.
6.6.10 Nakaoka, M., Aioi,
K., 1999. Growth of seagrass Halophila ovalis at dugong trails compared to existing
within-patch variation in a Thailand intertidal flat. Marine Ecology Progress
Series 184, 97-103.
6.6.11 Pielou, E.C., 1966. Shannon¡¦s formula
as a measure of species diversity: its use and misuse. American Naturalist 100,
463-465.
6.6.12 Qi, Z.Y., 2004. Seashells of
China. China Ocean Press. Beijing, China.
6.6.13 Qin, 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.
6.6.14 Shannon, C.E., Weaver, W., 1963.
The Mathematical Theory of Communication. Urbana:
University of Illinois
Press, USA.
6.6.15 Shin, 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.
6.6.16 Supanwanid, C., 1996. Recovery of the
seagrass Halophila ovalis 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.
6.6.17 Vermaat, 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.
6.6.18 Yang, D.J, Sun, R.P., 1988. Polychaetous annelids commonly seen from the Chinese waters
(Chinese version). China Agriculture Press, China.
7
Environmental Site
Inspection and Audit
7.1.1
Site 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 2, 9, 16, 25 and 30 September
2015.
7.1.2
Particular observations during the site inspections and the follow up actions taken by the
Contractor are described below.
2
September 2015
(a)
The alignment of silt
curtains did not follow the design plan at Portion X. The silt curtains was
realigned to follow the design plan. This observation was found on 22 July 2015 and closed on 2 September
2015.
(b)
A gap was observed between
sections of silt curtains at Portion X. The gap was filled up by additional
silt curtains. This observation was found on 22 July 2015 and closed on 2
September 2015.
(c)
Dry dusty material was found on the ground after the
loading/unloading activity at S7. The dry dusty
material was cleaned up by the Contractor. This observation was found on 5
August 2015 and closed on 2 September 2015.
(d)
A stockpile of dry crushed stones was found at S7. Water spraying was provided for the stockpile of dry crushed stone. This observation was found on 5 August 2015 and closed on 2 September
2015.
(e)
No drip tray was provided
for chemical containers at S15. A drip tray was provided for the chemical
containers. This observation was found on 12 August 2015 and closed on 2
September 2015.
(f)
The silt curtain which
should be placed around the aeronautical light was broken at Portion X. The
broken silt curtain around the aeronautical light at Portion X was replaced. This
observation was found on 19 August 2015 and closed on 2 September 2015.
(g)
The rubbish bin at access
road of WA6 was full. The rubbish was removed. This observation was found on 28
August 2015 and closed on 2 September 2015.
(h)
A drip tray was not provided to the chemical
containers inside West Tunnel. The chemical
containers were removed. This observation was found on 28 August 2015 and
closed on 2 September 2015.
(i)
A drip tray was not provided for the chemical
containers under the bridge at West Tunnel site. The chemical containers were removed. This observation was found on 28
August 2015 and closed on 2 September 2015.
(j)
The container for
collecting general wastes was full and rubbish was placed next to the container
at S15. The rubbish was removed by the Contractor. This observation was found
on 2 September 2015 and closed on 9 September 2015.
(k)
The alignment of the silt
curtain did not follow the design plan at Portion X. This observation has been
outstanding since 2 September 2015. The Contractor was reminded to follow the
design plan of silt curtain at Portion X.
(l)
Muddy water was leaked from
the wheel washing bay to the sea at S7. The muddy water discharge was stopped
by diverting the wastewater to a sump pit. This observation was found on 2
September 2015 and closed on 9 September 2015.
(m)
Stagnant water was
accumulated inside an I-beam at N4. The stagnant water was cleaned up by the
Contractor. This observation was found
on 2 September 2015 and closed on 9 September 2015.
(n)
Stagnant water was observed
inside a drip tray at N4. The stagnant water inside the drip tray was cleaned
up. This observation was found on 2 September 2015 and closed on 9 September
2015.
(o)
Many emptied cement bags
were placed on the ground at S11.
The emptied cement bags were removed. This observation was found on 2 September 2015 and closed on 9 September
2015.
(p)
Stagnant water was found
inside an abandon wheel washing bay at N20. The stagnant water was cleaned up inside the abandon wheel
washing bay. This observation was found on 2 September 2015 and closed on 16
September 2015.
9 September 2015
(a)
The alignment of the silt
curtain did not follow the design plan at Portion X. This observation has been
outstanding since 2 September 2015. The Contractor was reminded to follow the
design plan of silt curtain at Portion X.
(b)
Rubbish was accumulated on
the ground at N1. The rubbish was removed by contractor. This observation was
found on 9 September 2015 and closed on 16 September 2015.
(c)
There were not enough sand
bags to be placed along the boundary of dusty materials at N1. Additional sand
bags were placed along the boundary of the dusty materials. This observation
was found on 9 September 2015 and closed on 16 September 2015.
(d)
Sand bags placed along the
road were broken at N20. The broken sand bags were removed and new sand bags
were placed along the road. This observation was found on 9 September 2015 and
closed on 16 September 2015.
(e)
A container for general
refuse was full and rubbish was placed next to the container at S15. The rubbish was removed by the Contractor. This observation was found on 9
September 2015 and closed on 16 September 2015.
(f)
A wastewater treatment
plant was not used at S25. The wastewater was contained within the construction
site. After the site inspection,
the Contractor pump the wastewater to wastewater treatment plant for treatment
prior to discharge. This observation was found on 9 September 2015 and closed
on 16 September 2015.
(g)
Surface runoff was not
directed to a wastewater treatment system at N1. The surface runoff was pumped
to a wastewater treatment system for treatment after the site inspection. This observation was found on 9
September 2015 and closed on 16 September 2015.
(h)
Stagnant water was observed
inside an abandon wheel washing bay at N20. The stagnant water inside the
abandon wheel washing bay was cleaned up. This observation was found on 9
September 2015 and closed on 16 September 2015.
16 September 2015
(a)
The alignment of the silt
curtain did not follow the design plan at Portion X. This observation has been
outstanding since 2 September 2015. The Contractor was reminded to follow the
design plan of silt curtain at Portion X.
(b)
No sand bags were placed
around the storage area for aggregate / clay at vessel Shun Tat 82. Sand bags were
placed the around the storage area for aggregate / clay. This observation was found on 16 September 2015 and closed on 25
September 2015.
(c)
Rubbish was found near
seaside at S7. The rubbish was removed. This observation was found on 16
September 2015 and closed on 25 September 2015.
(d)
Muddy surface runoff was
observed at S7.
The muddy water runoff was stopped by the Contractor. This observation was
found on 16 September 2015 and closed on 25 September 2015.
(e)
A drilling machine was
partly covered and fugitive dust was observed at S15. A proper cover was provided
to the drilling machines at S15. This observation was found on 16 September
2015 and closed on 25 September 2015.
(f)
No labour was provided for
a wheel washing facility at WA4 to wash wheels of vehicles leaving the site. A
labour was provided to wash wheels of vehicles at WA4. This observation was
found on 16 September 2015 and closed on 25 September 2015.
(g)
A rubbish bin at WA6 was
full. The rubbish was removed. This observation was found on 16 September 2015
and closed on 25 September 2015.
(h)
Holes of water barriers
were not sealed at WA6. Holes of the water barriers at WA6 were sealed. This
observation was found on 16 September 2015 and closed on 25 September 2015.
25 September 2015
(a)
The alignment of the silt
curtain did not follow the design plan at Portion X. This observation has been
outstanding since 2 September 2015. The Contractor was reminded to follow the
design plan of silt curtain at Portion X.
(b)
Mechanical cover of dump
truck was not covered near at Portion Y. The mechanical cover of a dump truck
was closed during transportation of materials at Portion Y. This observation
was found on 25 September 2015 and closed on 30 September 2015.
(c)
Water dripping from
air-conditioner was observed at Portion Y. The Contractor used a red bucket to contain
the water dripping. This observation was found on 25 September 2015 and closed
on 30 September 2015.
(d)
Accumulated rubbish was
observed at Portion Y. The rubbish was removed. This observation was found on
25 September 2015 and closed on 30 September 2015.
(e)
No drip tray was observed
for the oil drums at Portion Y. Drip trays were provided for the oil drums.
This observation was found on 25 September 2015 and closed on 30 September
2015.
(f)
Stagnant water was observed
at Portion Y. The stagnant water was cleared up. This observation was found on
25 September 2015 and closed on 30 September 2015.
(g) Stagnant water was observed at S16 site entrance. The stagnant water was cleared up. This observation was found on 25 September 2015 and closed on 30
September 2015.
(h) Rubbish was observed inside the tunnel at N1. The rubbish
was removed. This observation was found
on 25 September 2015 and closed on 30 September 2015.
30 September 2015
(a)
The alignment of the silt
curtain did not follow the design plan at Portion X. This observation has been
outstanding since 2 September 2015. The Contractor was reminded to follow the
design plan of silt curtain at Portion X.
(b)
Muddy water was leaked out from
holes of sand bucket into the sea from the storage area at Shun Tat 82. The Contractor was
reminded to block the holes of the sand bucket and stop leaking of muddy water.
(c)
The alignment of silt
curtain for barging point did not follow the design plan at Portion X. The
Contractor was reminded to follow the design plan of silt curtain at Portion X.
(d)
No sand bags were placed
along the road at N20. The Contractor was reminded to place sand bags along the
road at N20.
(e)
Wheels of a dump truck were
not washed before leaving the site at N20. The Contractor was reminded to provide
wheel washing for the dump truck before leaving the site at N20
(f)
Stagnant water pool was
observed on surface at S8. The Contractor was reminded to clean up the stagnant
water at S8.
(g)
No water spraying was provided
for drilling activity at S8. The Contractor was reminded to provide the water
spraying for drilling activity at S8.
(h)
Unpaved road was dry and fugitive
dust emission was observed when there was vehicle movement at S16. The
Contractor was reminded to spray water regularly on the unpaved road at S16.
(i)
No sand bags were placed along
the site boundary at S25 and there was a potential to wash away the sand into
the sea. The Contractor was reminded to provide sand bags along the site
boundary at S25.
(j)
A wastewater treatment was
not used at S25. The Contractor was reminded to use the wastewater treatment system
at S25 if necessary.
(k)
General waste was
accumulated on bare ground at S25. The Contractor was reminded to collect the general
waste and disposal of regularly at S25.
The 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.
7.2
Advice
on the Solid and Liquid Waste Management Status
7.2.1
The Contractor registered as a chemical waste producer
for the Project. Sufficient numbers of receptacles were available for general
refuse collection and sorting.
7.2.2
Monthly summary of waste flow table is detailed in Appendix J.
7.2.3
The Contractor was reminded that chemical waste
containers should be properly treated and stored temporarily in designated
chemical waste storage area on site in accordance with the Code of Practice on
the Packaging, Labelling and Storage of Chemical Wastes.
7.3.1
The valid environmental licenses and permits during
the reporting month are summarized in Appendix
L.
7.4.1
In response to the site audit findings, the
Contractors have rectified
most of the observations as
identified during environmental site inspections during the reporting month.
Follow-up actions for outstanding observations will be inspected during the
next site inspections.
7.4.2
A summary of the Implementation Schedule of
Environmental Mitigation Measures (EMIS) is presented in Appendix M. Most of the necessary mitigation measures were
implemented properly.
7.4.3
Regular marine travel route for
marine vessels were implemented properly in accordance to the submitted plan
and relevant records were kept properly.
7.4.4
Dolphin Watching Plan was
implemented during the reporting month. No dolphins inside the silt curtain
were observed. The relevant records were kept properly.
7.5.1
No Action and Limit Level
exceedances of 1-hour TSP and 24-hr TSP level were recorded
at AMS5 and AMS6 during the reporting month.
7.5.2
For construction noise, no Action and Limit Level exceedances were
recorded at the monitoring stations during the reporting month.
7.5.3 For marine
water quality monitoring, one Action Level exceedances of suspended solid level were recorded
during the reporting month. No Limit Level exceedance of suspended solid level
was recorded. No Action Level/ Limit Level exceedances of turbidity
level and dissolved oxygen level were recorded during the reporting month.
7.6
Summary of Complaints, Notification of Summons and
Successful Prosecution
7.6.1 There were no
complaints received during the reporting month. However, EPD informed SOR and IEC
that there was an enquiry regarding untreated wastewater discharge on 29
September 2015 via email. An
investigation is being undertaken and investigation report will be sent to EPD
for record. The details of cumulative
statistics of Environmental Complaints are provided in Appendix K.
7.6.2 No notification of
summons and prosecution was received during the reporting period.
7.6.3 Statistics on
notifications of summons and successful prosecutions are summarized in Appendix N.
8.1.1
As informed by the Contractor, the major construction
activities for October 2015 are summarized in Table 8.1.
Table 8.1 Construction
Activities for October 2015
Site Area
|
Description of Activities
|
Portion X
|
Dismantling/Trimming
of Temporary 40mm Stone Platform for Construction of Seawall
|
Portion X
|
Filling
Works behind Stone Platform
|
Portion X
|
Construction of Seawall
|
Portion X
|
Loading and Unloading of
Filling Material
|
Portion X
|
Pipe Piling
|
Portion X
|
Band Drains Installation
|
Portion X
|
Excavation and Lateral Support Works at Scenic Hill Tunnel (Cut &
Cover Tunnel)
|
Portion X
|
Laying Blinding Layer for Tunnel Box Structure at Scenic Hill Tunnel
(Cut & Cover Tunnel)
|
Portion X
|
Construction of Tunnel Box Structure at Scenic Hill Tunnel (Cut &
Cover Tunnel)
|
Portion X
|
Socket H-Piling work at Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Construction of Sheet Pile at Scenic Hill Tunnel (Cut & Cover Tunnel)
|
Portion X
|
Excavation Works for HKBCF to Airport Tunnel
|
Portion X
|
Sheet Piling Works for HKBCF to Airport Tunnel East (Cut & Cover
Tunnel)
|
Portion X
|
Socket H-Piling works for HKBCF to Airport Tunnel East (Cut &
Cover Tunnel)
|
Portion X
|
Pipe Piling works for HKBCF to Airport Tunnel East (Cut &Cover
Tunnel)
|
Airport Road
|
Works for Diversion of
Airport Road
|
Airport Road / Airport Express Line/East Coast Road
|
Utilities Detection
|
Airport Road / Airport Express Line/East Coast Road
|
Establishment of Site Access
|
Airport Road/Airport Express Line
|
Canopy Pipe Drilling/ Mined Tunnel Excavation/ Box Jacking underneath Airport
Road and Airport Express Line
|
Kwo Lo Wan Road
|
Excavation and Lateral Support Works at shaft 3 extension north shaft
& south shaft
|
Airport Road
|
Excavation and Lateral Support Works for HKBCF to Airport Tunnel West
(Cut & Cover Tunnel)
|
Portion Y
|
Utility Culvert Excavation
|
Portion Y
|
Highway Operation and Maintenance Area Building Foundation &
Sub-structure Works
|
West Portal
|
Excavation for Scenic Hill Tunnel
|
West Portal
|
Ventilation Building Foundation and Superstructure Works
|
8.2
Environmental Monitoring Schedule for the Coming
Month
8.2.1
The tentative schedule for environmental monitoring in October 2015 is
provided in Appendix D.
9.1.1
The construction phase and EM&A programme of the
Contract commenced on 17 October 2012.
Air Quality
9.1.2
No Action and Limit Level
exceedances of 1-hour TSP and 24-hr TSP level were recorded
at AMS5 and AMS6 during the reporting month.
Noise
9.1.3
For construction noise, no Action and Limit Level
exceedances were recorded at the monitoring stations during the reporting
month.
Water Quality
9.1.4 For marine
water quality monitoring, one Action Level exceedances of suspended solid level were recorded
during the reporting month. No Limit Level exceedance of suspended solid level
was recorded. No Action Level/ Limit Level exceedances of turbidity
level and dissolved oxygen level were recorded during the reporting month.
Dolphin
9.1.5
During the September¡¦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.
9.1.6
Due 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 (September 2015 ¡V November 2015) and baseline monitoring period (3-month period) will be made.
Mudflat
9.1.7
This measurement result was generally and relatively higher than the
baseline measurement at S1, S2, S3 and S4. The mudflat level is continuously
increased.
9.1.8
The September 2015 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
9.1.9
Environmental site inspection
was carried out on 2, 9, 16, 25 and 30 September 2015. Recommendations on remedial actions were
given to the Contractors for the deficiencies identified during the site
inspections.
9.1.10
There were no complaints
received in relation to the environmental impact during the reporting period.
9.1.11
No
notification of summons and prosecution was received during the reporting
period.