Expansion of Hong Kong International Airport into a Three-Runway System |
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Marine Travel Routes and Management Plan for High Speed Ferries of SkyPier |
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Chapter Title
Figure 1‑1 Key Traffic Routes
for Future Traffic Environment
Figure 2‑3 Recommended
Route Diversion and the PRE CWD National Nature Reserve
Figure 3‑1 Various Marine
Constraints in the North Lantau Waters
Figure 3‑2 Existing Marine Traffic Plan (BMT, 2014)
Figure 3‑3 Pre-defined Marine
Travel Route for SkyPier HSFs operating to / from Zhuhai and Macau
Figure 3‑8 Dolphin Habitat
Index Developed for this Plan
Figure 3‑9 Speed Controlled
Zone for SkyPier HSFs
Figure 3‑10 Density of Chinese
white dolphins from HZMB-HKLR Monitoring Reports
Figure 3‑11 Marine Prohibited
Zone for SkyPier HSFs
Figure 3‑12 EIA Forecast of
Daily Average SkyPier HSFs in 2021 and 2030
Table
Table 2-1 Summary of HSF impacts on CWDs
(excerpt from Table 13-29 of the EIA Report)
Table 2-2 Speed of High Speed Ferry and the
Corresponding Sound Pressure Level
Government
of the Hong Kong Special Administrative Region (HKSAR) approved in principle
the adoption of the Three-Runway System (3RS) as the future development option
for Hong Kong International Airport (HKIA) for planning purposes on 20 March
2012, and also approved the recommendation of Airport Authority Hong Kong
(AAHK) to proceed with the statutory environmental impact assessment
(EIA). An EIA study
brief (ESB-250/2012) for the 3RS project (henceforth referred to as the
‘project’) was issued by the Environmental Protection Department (EPD) on 10
August 2012. The EIA report has been prepared according to the EIA study
brief requirements, which identified 12 key environmental assessment aspects to
be addressed as part of the EIA study.
On 7 November 2014, the EIA for the project (EIA Register No.:
AEIAR-185/2014) was approved and an Environmental Permit (EP) (Permit No.:
EP-489/2014) was issued for the project.
The
project is proposed to be located on a new land formation immediately north of
HKIA in North Lantau, covering a permanent footprint of approximately 650 ha.
As stated in the approved EIA, the project primarily comprises:
§ New
third runway with associated taxiways, aprons and aircraft stands;
§ New
passenger concourse building;
§ Expansion
of the existing Terminal 2 (T2) building; and
§ Related airside and landside works, and associated ancillary and supporting facilities.
The area around HKIA is
well used by a variety of vessel types, of which High Speed Ferries (HSFs) pose
the most significant collision threat to Chinese White Dolphins (CWDs) and are
also known to generate the loudest underwater noise. During the 3RS land
formation, works area will be designated and demarcated by floating booms and
as the land for the 3RS new platform is formed, the navigation routes for these
vessels will be constrained to within a narrower area just north of the new
Hong Kong International Airport Approach Area (HKIAAA; Figure
1‑1),
although no change to the direction of traffic flows are expected, these
continuing to comprise two-way transits east and west.
Figure 1‑1 Key Traffic Routes for Future Traffic Environment
In
accordance with Clause 2.10 of the EP, the permit holder shall submit a Marine
Travel Routes and Management Plan (The Plan) for high speed ferries (HSF) of
the SkyPier. The Plan shall include at least the
following information/specifications:
i.
The
imposition of a speed limit within Hong Kong waters which are hotspots of the
CWD during the construction phase so as to minimize chances of collision and
disturbance to the CWD;
ii.
To
cap the number of SkyPier HSF at the current level of
operation (i.e. an annual daily average of 99) prior to designation of the
proposed marine park; and
iii.
Explore
the feasibility of imposing a daily cap on the number of HSF leaving the SkyPier and imposing further speed restriction at different
spots along the marine routes after detailed study.
This Plan
has been prepared to detail the information/specifications listed above to
fulfil the EP requirement Clause 2.10.
SkyPier, which is located at north-east of Hong Kong
International Airport (HKIA), provides HSF service for transfer passengers to
eight ports in Pearl River Delta (PRD) and Macao include Dongguan Humen, Guangzhou Nansha, Macao Maritime
Ferry Terminal, Macao Taipa, Shenzhen Fuyong, Shenzhen Shekou, Zhongshan and
Zhuhai Jiuzhou. The draft of SkyPier
HSFs travelling in the waters north of Lantau Island is approximately 1 – 2 m.
This plan focuses on those SkyPier HSFs traveling to
/ from Macau and Zhuhai as the route for these services passes through waters
between the Hong Kong International Airport Approach Area (HKIAAA) and the Sha
Chau and Lung Kwu Chau Marine Park (SCLKCMP), which
is identified in the approved EIA report as an important travelling area for
CWDs requiring the development of mitigation measures at both the construction
and operation phases of the 3RS project in order to reduce identified impacts
to an acceptable level..
Photo 2-1 Photo of High Speed
Ferry
The approved EIA Report
including the literature review and the project specific dolphin survey
findings have identified that the waters to the north of the existing airport
are an important travelling area for CWDs, noting that CWDs use this area
mainly for moving between the main feeding areas or known areas of higher CWD
abundance around the Brothers, in west Lantau and around Sha Chau and Lung Kwu Chau.
The approved EIA assessed the
indirect impacts of HSFs currently navigating in the waters between the Hong
Kong International Airport Approach Area and the SCLKCMP on CWDs (i.e. the CWD
travelling area) at both the construction and operational phases. Identified
impacts included increased acoustic disturbance, changes to CWD movement
patterns, and increased risk of injury/mortality associated with marine traffic
were assessed in the EIA and are summarized in Table
2‑1
below (extracted from Table 13-29 of the EIA Report.
Table 2‑1 Summary of HSF impacts on CWDs (excerpt from Table 13-29 of the EIA
Report)
Potential Impact |
Source |
Receiver |
Significance of
Impact |
Further Mitigation
/ Enhancement Required |
Construction Phase |
||||
Increased acoustic disturbance from changes to
marine vessels and ferry traffic |
HSF |
CWD |
Moderate |
Yes |
Changes to CWD movement patterns as a result of
marine traffic |
HSF |
CWD |
Moderate |
Yes |
Increased risk of injury/ mortality to CWDs from
marine traffic |
HSF |
CWD |
High |
Yes |
Operational Phase |
||||
Increased acoustic disturbance from increased marine
traffic |
HSF |
CWD |
Moderate-high |
Yes |
Changes to CWD movement patterns from marine traffic |
HSF |
CWD |
Moderate-high |
Yes |
Increased
risk of injury/ mortality |
HSF |
CWD |
High |
Yes |
The EIA for 3RS described that the
HSFs utilising the SkyPier would move up to full
speed of 30 - 40 knots in 1-1.5 km after leaving the pier and would slow down
within approx. 1 km of approaching the pier. The HSFs would move at high speed
while navigating through the waters north of the airport island. Data from the
AFCD long-term studies (Hung 2012, 2013) and the intensive one-year study
conducted for the 3RS EIA identify that such vessel movements caused intermittent
behavioural changes in CWDs as they attempt to avoid rapid and noisy ferry
approaches, especially while foraging or transiting across ferry lanes.
However, the EIA recognised that the risks to CWDs decrease as vessel speeds
are reduced and therefore, any reduction in speed from 30-40 knots will reduce
potential adverse impacts on CWDs.
Based upon the newly constrained stretch of marine waters between the
new HKIAAA and Sha Chau and Lung Kwu Chau Marine Park
(SCLKCMP) that HSFs and CWDs would have to share, and the increased risk of
collision leading to serious injury and mortality for the CWDs, the issue is
considered a high impact and effective mitigation measures, as detailed in Section 2.3, will be needed.
The 3RS EIA described the data
presented by Sims et al. (2012) show that the HSFs of Hong Kong release a lot
of noise energy into the marine environment along their travel route, with a
ferry approaching at a speed greater than 20 knots at 166 m distance from the
hydrophones, resulting in an overall sound pressure level of around 120 dB re. 1 ųPa, with levels still being as
high as 100-105 dB at a distance of 565m, in the CWD communication range of
about 3 kHz and higher. CWD sounds have been measured as about 168 dB
re. 1ųPa at their source (Li et al. 2012), 1 m distance from the CWD’s
head, and since their sounds attenuate strongly with distance, there is a
potential that fast ferries mask or restrict the range of CWD communications.
It was hence concluded that the noise impacts from SkyPier
HSFs on CWDs is considered to be of moderate impact significance during
construction phase and of moderate-high impact significance during operation
phase, requiring mitigation as detailed in Section 2.3.
The effects of vessel traffic on
cetaceans around the world have been well documented in the past. Behavioural
changes such as spatial avoidance, increase in
swimming speed, changes in diving behaviour and acoustic behaviour, which could
be regarded as impact, have been studied extensively in various studies (Hung,
2012). While the general idea that vessel noise affects cetaceans is
well-established (Jensen et al., 2009), there is currently no published study
which has investigated the impact of noise level and speed of HSF specifically
on CWD behaviour. However, a number of studies as discussed below identifies
that speed reduction of HSF can reduce the underwater noise level generated,
and subsequently the impact on CWD communication and behaviour is anticipated
to be lessened.
A recent
study measured the underwater radiated noise from a high-speed jet propelled
watercraft while the vessel passed at speeds of 12, 24 and 37 knots (Rudd et
al., 2014). The broadband
(0-22kHz) sound pressure levels of the ship at all directions (i.e. bow aspect,
broadside aspect and stern aspect) decreased up to 20dB, when the speed was reduced
from 37 knots to 12 knots. Evidence from the passive acoustic monitors termed
Ecological Acoustic Recorders (EAR) data collected during the 3RS EIA shows
comparable information. High speed
ferries were tracked by the land-based theodolite station at the northeast of
the HKIA, with the underwater sound simultaneously recorded by the nearest EAR
Station at approximately 500 m from the existing HSF route. Sound pressure
levels in the 4-8 kHz octave band (important for CWD whistle communication)
proportional to HSFs speed were recorded, with each sound level calculated as a
mean from 5 ferries per speed category from 6-8 knots to 26-30 knots (see Table 2‑2 ). A
reduction of about 60% underwater sound energy in the CWD whistle communication
frequency were found by comparing of the measurement results of 26-30 knots HSF
speed and that of 15 knots, and similar underwater noise reduction will be
expected by slowing the HSFs from 30-40 knots to 15 knots. Therefore both
literature and field data show that slowing the HSFs from 30-40 knots to 15
knots will substantially reduce the noise levels approximately by 60%
underwater sound energy or 4dB so as to alleviate the acoustic disturbance to
the CWDs.
Table 2‑2 Speed of
High Speed Ferry and the Corresponding Sound Pressure Level
Speed of HSF (knots) |
Sound Pressure Level (dB)* |
6-8 |
97 |
11-20 |
99 |
21-25 |
100 |
26-30 |
103 |
* sound
pressure levels in the 4-8 kHz octave band at an average distance of 500 m from
the EAR station
A
Cumulative Effects Assessment (CEA) taking data from 1996 to 2013 conducted by Marcotte et al.
(2015) indicated a long-term effect of HSF traffic on CWD travelling behaviour
and distribution, as operation of SkyPier HSFs was
linked by these authors to reduced dolphin occurrence especially in the
Brothers Islands area to the east of the existing airport, and at the same time
the dolphin density within SCLKCMP increased.
An Australian study revealed the
indirect impact of transiting boat traffic (i.e. the boats which travelled
through the CWD habitat without approaching the dolphins for the purpose of
viewing them) on the acoustic behaviour of CWDs (Van Parijs
and Corkeron, 2001). The boats’ passage did not
affect the rates at which CWDs produced click trains and burst pulse
vocalizations, however, CWDs significantly increased their whistling rate
immediately after a boat had passed through but was still within 1.5 km from
the CWD groups. The study suggested that the noise from transiting vessels
affected the CWD group cohesion, and the dolphins need to re-establish vocal contact
with associates after the masking noise of the vessel had passed. In
particular, mother-calf pairs produced the highest whistle rate, probably
demonstrating their greater need to reassure each other of their presence. With
the attenuation in noise levels associated with HSF speed reduction, it is
anticipated that due to the reduction on underwater noise energy generated, the
impact on CWD communication would be diminished, and the dolphins probably
would not need to expend as much energy in adjusting the timing of their
signals.
In
addition, underwater noise shifts in loudness and pitch attendant with vessel
speed changes present a particularly-strong disturbance as gear shifts are
found to produce broadband (0 -35 kHz) and high-level sound (peak-peak source
levels of up to 200 dB re 1μPa) of high amplitude, short-duration and
reverberant nature, which is much higher than regular engine noise (around
90-130dB re 1μPa) (Jensen et al. 2009). Therefore, rapid and frequent
speed changes should be avoided to reduce both disturbance to CWDs and also
potential vessel/CWD collisions. The simple change in speeds (change in
"closing-in distance") may also present an extra physical danger to
marine mammals because of the added unpredictability of where the boat will be
relative to the animals (Rudd et al. 2014). In other words, it is likely that
dolphins can anticipate the imminent arrival of a vessel from the approaching
noise (Scheer and Ritter 2013), but would be confused
as to anticipation of when the boat would be above or near them by a sudden
change in boat speed (see also Würsig and Evans, 2001
for a general discussion of boat operations near cetaceans).
In view of
the moderate to high indirect impacts to CWDs resulting from HSFs (see Table 2‑1),
mitigation measures in relation to marine traffic control need to be specified
to reduce acoustic disturbance, risk of injury or mortality and changes to
abundance and patterns of habitat use. Once the project construction is
underway, the paths of vessel movements from the east side of the airport
platform to the waters west of Hong Kong will be further restricted. The EIA
Report identified that having an increasing number of high-speed vessels, using
a narrower corridor of movement, results in closer spacing of the vessels and
less area for CWDs to surface without increased risk of being hit by a vessel
and exposure to higher levels of anthropogenic noise, this known to cause
behavioural disturbance to dolphins.
In the approved EIA report, route diversions to the
north of SCLKCMP for SkyPier HSFs operating to / from
Zhuhai and Macau were proposed to mitigate the potential impacts on CWDs
resulting from HSFs using a narrower navigation corridor between SCLKCMP and
the new 3RS land formation. It is anticipated that HSFs using a narrower
corridor would result in closer spacing of the vessels and a reduced area for
CWDs to surface leading to increasing risk of being hit by HSFs and disturbance
from increased anthropogenic noise. For the section of diverted route passing
through high CWD abundance grid squares, a 15-knot speed controlled zone is
proposed to reduce potential adverse impacts on CWDs within these areas. The
reduction in speed to 15 knots is expected to reduce collision risk and result
in less acoustic and behavioural disturbance to CWDs. During simulations of the
HSF route diversion (e.g. a Full Bridge Simulation Workshop was undertaken) it
was determined that HSFs can operate much more reliably at 15 knots rather than
at 10 knots in the vicinity of the proposed speed controlled zone. It was also found that HSFs
operating at 10 knots for a long distance would be more likely to cause sea
sickness, especially under choppy sea conditions. Therefore, the 15 knots speed
restriction was determined to be optimal with an acceptable reduction in risk
to CWDs.
Before the end of 2015 it
is proposed that SkyPier HSFs operating to / from
Zhuhai and Macau would divert north of the SCLKCMP with a 15 knot speed limit
to apply for the part-journey crossing high CWD abundance grid squares. This
mitigation is considered effective as it will be adopted by all SkyPier HSFs operating to / from Zhuhai and Macau
(constituting up to 60% of the HSFs in this area) and it would avoid the
current situation of the SkyPier HSFs travelling to
Zhuhai and Macau passing south of the SCLKCMP at high speeds thereby
substantially reducing the impacts of these vessels in this area
Figure
2‑1.
Figure 2‑1 Marine Traffic Forecast of HSFs Navigating between HKIA Approach Area
and South of the SCLKCMP
Source:
Extracted from 3RS EIA Report – Table 13-27; Appendix 13.13 Figure 1b and Table
2
It is
also noteworthy that the SCLKC North diverted route is expected to result in
less impact on CWD travelling areas, as the stretch of navigation waters for
the diverted route going via SCLKC north
is much wider (approx. 2.4km) than that of the existing route along the
airport north (approx. 0.6km) (See Figure 2‑2).
SkyPier HSFs using the diverted route going via SCLKC
north will have less conflict with the CWD travelling area and hence less risk
of collision with CWD. The
diverted route via SCLKC north will also reduce the SkyPier
HSF travel time across the “Core Area” of the Pearl River Estuary (PRE) CWD
National Nature Reserve (see Figure
2‑3).
Figure 2‑2 Stretch of Navigation Waters for the Diverted Route to SCLKC North and
the Existing Route along Airport North
Figure 2‑3 Recommended Route Diversion
and the PRE CWD National Nature Reserve
The number of SkyPier
HSFs using the existing route was 34 in 2011 and projected to increase to
approx. 50 in 2030 compared to approx. 540 total vessels using Urmston Road in
2011 and projected to increase to approx. 810 in 2030 (see Table
2‑3)
(i.e. about 6% of the total marine traffic in Urmston Road). While the
additional diverted traffic (typically 1 – 4 movements per hour during SkyPier HSF operating hours) does make Urmston Road
marginally busier, the number of additional vessels is not significant compared
to the total marine traffic in Urmston Road and is not anticipated to result in
any congestion problem. Even with the proposed SkyPier
(Macau / Zhuhai) HSF route diversion, the marine traffic density in Urmston
Road in the future would remain lower than the marine traffic density in
certain other Hong Kong shipping channels, for example in the Western Harbour
where marine traffic density is higher (see Figure
3‑2).
It is noted that even these busy areas of Hong Kong waters do not experience
significant congestion issues, it is therefore summarised that the proposed SkyPier (Macau / Zhuhai) HSF route diversion will not lead
to any significant added congestion in Urmston Road. In addition, the diverted
route of SkyPier HSF will be along the western part
of Urmston Road and will therefore avoid overlapping with majority of the
existing marine traffic along the eastern part of Urmston Road.
Table 2‑3 Daily Average of High-Speed Ferries and Total Maine Traffic in Year
2011 and Projection to Year 2030:
Year |
Daily Average (High-Speed Ferries) |
Daily Average (Total Marine Traffic) |
|
SkyPier |
Non-SkyPier |
||
(i) via South Sha Chau |
|||
2011 |
34 |
24 |
Approx. 230 |
2021 |
Approx. 45 |
Approx. 30 |
NA |
2030 |
Approx. 50 |
Approx. 35 |
Approx. 330 |
(ii) via Urmston Road |
|||
2011 |
54 |
54 |
Approx. 540 |
2021 |
Approx. 70 |
Approx. 70 |
NA |
2030 |
Approx. 80 |
Approx. 80 |
Approx. 810 |
It is considered unsafe for HSFs (with a draft of approximately 1 - 2m) to travel in shallow water zones where water depth is less than 2m. The western and northwestern waters of Urmston Road Anchorage Area contain several shallow water zones with general water depth of less than 2 m (see Figure 3‑1). Therefore, the diverted route of HSFs should avoid those areas due to safety concerns.
Figure 3‑1 Various Marine Constraints in the North Lantau Waters
There are restricted areas in the vicinity of Hong Kong International Airport (i.e. HKIAAA) where vessels are not allowed to pass through without authorization. The diverted route shall avoid the HKIAAA as shown in Figure 3‑1.
The local constraints imposed by the works area of the 3RS project or adjacent projects (e.g. the Hong Kong-Zhuhai-Macao-Bridge HKBCF/ Tuen Mun-Chek Lap Kok Link (TM-CLKL)), SCLKCMP, and other marine facilities such as the Urmston Road Anchorage (see Figure 3‑1) shall also be considered in designing marine travel routes for SkyPier HSFs.
The proposed temporary works area of the 3RS project will be demarcated by floating booms, and the route of HSFs need to be designed to avoid entering any construction works area for safety reasons.
According to the Marine Parks Ordinance (Cap.476) and the Marine Parks and Marine Reserves Regulation (Cap. 476A), any operating vessels are not allowed to travel at speed exceeding 10 knots inside Marine Park. Besides, to minimise disturbance to the SCLKCMP, the route alignment of SkyPier HSFs shall avoid the Marine Park.
For the Urmston Road Anchorage, in view of the marine vessels that may anchor at this area, it is proposed to avoid routing the diverted route through this area due to safety concerns and potential operational impacts.
Areas with high CWD abundance (e.g. in and around Sha Chau and Lung Kwu Chau Marine Park) form another constraint to be
considered during the
design of the marine traffic route. As discussed in the sections above, other issues such as water depth, HKIAAA and other facilities are
absolute constraints that have to be avoided due to safety concerns and
potential operational impacts. However it is feasible for the diverted route to
pass through areas with high CWD abundance provided that there is suitable
mitigation measure (i.e. speed reduction) to minimise the impact of the HSFs on
CWDs in these areas. In Section 3.3, a dolphin habitat rating system is developed based on recent data for designation of
speed controlled zone along the proposed diverted route, which can reduce the
impact on CWDs. With the provision of proper training to HSF captains that they
can strictly follow the pre-defined travel route (see Section 4.4.1) The disturbance to dolphins (which would presumably adapt to the
predictable routes) due to vessel movements would be reduced.
The design of proposed marine travel route for SkyPier HSFs has taken into account the various marine constraints as discussed in Section 3.1.
The captain shall strictly follow all navigation safety requirements (e.g. local regulations and requirements of the Marine Department) and relevant international practices. The marine travel route will be fine-tuned locally for safety reasons, taking into account other marine vessels that may be encountered. For instance, at Urmston Road where the traffic density is relatively high (see Figure 3-2), sudden sharp angle turning with high speed is not encouraged. The navigation route may also be affected by natural conditions such as wind, current, wave, poor visibility, extreme weather event etc.; special events such as closure of routes due to fireworks and other events; and avoidance of shallow water areas and stranded ships.
Figure 3‑2 Existing Marine Traffic Plan (BMT, 2014)
Note: The unit
Kilometers / Square Kilometer describes the total length of vessel routes
within each square kilometer.
An
indicative diverted marine travel route for HSFs travelling between SkyPier and Zhuhai or Macau is shown in Figure 3‑3.
Upon leaving or arriving at SkyPier, the HSFs have to
make a slight detour around the HKIAAA and temporary works area of the 3RS
project. For the water space between HKIA and Pillar Point/ Castle Peak Power
Station, sharp angle turning in high speed is avoided in Urmston
Road due to safety navigation issues. In order to avoid going through the Urmston Road Anchorage and SCLKCMP, the proposed route has
to pass through the channel between these two areas. As discussed in Section
3.1.1, it is not feasible to divert the route to north of Urmston Road Anchorage as the HSFs then have to transit
through northwest and west of the Urmston Road
Anchorage, which are shallow water zones with general water depth less than 2
m. Doing so would be unsafe.
Figure 3‑3 Pre-defined Marine Travel Route for SkyPier
HSFs operating to / from Zhuhai and Macau
In order to determine the area to which HSF speed limits should be
applied for reducing impacts on CWDs, data from the AFCD long-term surveys (see
Hung 2014 for a description of these data) have been evaluated to make the best
possible determination of the relative value of each 1 x 1 km grid for use in
this exercise. The latest available data including the recent marine mammal
monitoring report (Hung, 2015) has been taken into account for developing the
dolphin habitat index.
It was decided that, in order to avoid potential biases from any single
measure, a matrix of four measures of dolphin use of each grid would be used.
For each 1 x 1 km grid in the potential HSF route area, four factors have been
considered:
1)
Current density by
DPSE, i.e. the number of CWDs per 100 units of survey effort in the 1 x 1 km
grid (Figure
3‑4;
from Hung 2015)
2)
Historical density by
DPSE (Figure
3‑5;
from Hung 2014)
3)
Habitat rating (Figure
3‑6;
from Hung 2014)
4)
50% core area usage
by CWDs (Figure
3‑7;
from Hung 2014)
All of these four factors are based on dolphin numbers per unit effort,
but including data on the four factors helps to ensure the analysis has broad
temporal and biological relevance, and minimizes impacts of potential data
anomalies from using just a single factor. A matrix of the relevant data was
compiled. For each 1 x 1 km grid, there are four values presented,
corresponding to the four factors listed above, and for each one evaluated as
“Low”, “Medium” or “High” (note that these are subjective descriptive terms,
though objective quantitative values for building the matrix were used). For
densities (both current and historical), the corresponding values for “Low”
were 0.0-20.0, 20.1-40.0 for “Medium”, and 40.1 or above for “High”. For habitat
ratings, the corresponding values for “Low” were 0-10, 11-20 for “Medium”, and
21 or above for “High”. For 50% core
areas, the corresponding values for “Low” were 0-10, 11-30 for “Medium”, and 31
or above for “High”. Relevant raw data are presented in detail in Hung (2014)
and Hung (2015). The dolphin habitat index is then developed for each grid as
shown in Table 3‑1.
Table 3‑1 Criteria for each 1 km2 grid in defining the dolphin habitat
index, based on the ranking of four factors (i.e. current density by DPSE,
historical density by DPSE, habitat rating and 50% core area usage by CWDs)
Dolphin habitat index |
Criteria |
Least
Critical |
·
3 “Low”; or ·
4 “Low” |
Less
Critical |
·
2 “Medium” and 2 “Low”; or ·
1 “High” and 1 “Medium” and 2 “Low” |
Moderately
Critical |
·
2 “High” and 1 “Medium”; or ·
2 “High” and 2 “Low”; or ·
1 “High” and 2 “Medium”; or ·
3 “Medium” |
Highly
Critical |
·
3 “High”; or ·
4 “High” |
The resulting matrix (see Figure
3‑8)
demonstrates a highly critical CWD habitat to the northeast of SCLKCMP. It is
well-known that HSFs can adversely impact cetaceans, both by behavioral disturbance and ship strikes (see Van Waerebeek et al. 2007, Ritter 2010, Carrillo and Ritter
2010). SkyPier
ferries can significantly reduce impacts on dolphins by slowing to 15 knots in
this section of important dolphin habitat extending all the way to the HK/PRC
boundary.
Figure 3‑4 Current density of Chinese White Dolphins with corrected survey effort
per km2 in waters around Lantau Island between January – December
2014 (number within grids represent “DPSE”
= no. of dolphins per 100 units of survey effort; from Hung, 2015). In
the dolphin habitat index developed for this plan, DPSE of 0.0 – 20.0 is rated
as “Low”, 20.1 – 40.0 as “Medium” and 40.1 or above as “High”.
Figure 3‑5 Historical density of Chinese White Dolphins with correct survey effort
per km2 in waters around Lantau Island during 2001 – 2012 (numbers
within grids represent “DPSE” = no. of dolphins per 100 units of survey effort;
from Hung, 2014). In the dolphin habitat index developed for this plan, DPSE of
0.0 – 20.0 is rated as “Low”, 20.1 – 40.0 as “Medium” and 40.1 or above as
“High”
Figure 3‑6 Habitat rating of Chinese White Dolphins in Hong Kong using
quantitative habitat use information collected during 2001 – 2012 (number with
grids represents the sum of scores totalled from 10 selection criteria; from
Hung, 2014). In the dolphin habitat index developed for this plan, habitat
rating of 0 – 10 is rated as “Low”, 11 – 20 as “Medium”, and 21 or above as
“High”
Figure 3‑7 Number of individual Chinese White Dolphins with their 50% utilization
distribution (UD) core areas overlapped with each 1 km2 grid in
waters around Lantau Island from 2001 – 2012 (Hung, 2014). In the dolphin
habitat index developed for this plan, 50% core area of 0-10 is rated as “Low”,
11-30 as “Medium”, and 31 or above as “High”
Figure 3‑8 Dolphin Habitat Index Developed for this Plan
The
indicative diverted marine travel route in Section 3.2 is overlaid with the Dolphin
Habitat Index developed in Section 3.3 to determine the location of
speed controlled zone (SCZ) along the route. The proposed marine travel route
together with the 15-knot SCZ is shown in Figure 3‑9.
Figure 3‑9 Speed Controlled Zone for SkyPier HSFs
As illustrated in Figure 3‑9,
for the waterspace
between HKIA and Pillar Point/ Castle Peak Power Station, the route shall mainly transit through the “Least Critical” dolphin habitat
grids. When
leaving and/ or approaching the SkyPier terminal at
the HKIA, ferries should gradually increase and/ or decrease speed. On approaching the “Highly
Critical” dolphin habitat grids around SCLKCMP, they are required to enter a
defined 15-knot SCZ at the north and northeast of SCLKCMP. They are required to
enter and/ or leave the SCZ through Gates A-B-C and E-F (see Figure 3‑9), hence their movement through the
“Highly Critical” dolphin habitat is restricted, which would minimise their
chances of encounter with CWDs (and may allow dolphins to habituate to these
predictable routes). When travelling through the SCZ, they must adhere to the
speed limit of 15 knots, and as such they have to decelerate gradually before entering the SCZ, and can only increase the speed to over 15 knots upon
leaving the SCZ
gradually to avoid rapid speed changes. As mentioned in Section 2.2.3, rapid and
frequent speed changes should be avoided to reduce both disturbance to CWDs and
also potential vessel / CWD collisions, and it will be communicated to HSF
captains during the skipper training workshops that they need to reduce speed
gradually reaching 15 knots or less before entering the SCZ, and increase speed
gradually also upon leaving the SCZ. Should the SkyPier
HSFs that use the Urmston Road to travel north into the PRE also interface with
the speed restriction area for the SkyPier HSFs operating
to / from Zhuhai and Macau, then they would also be required to adhere to the
15 knot speed restriction.
The CWD density grids from the Hong Kong-Zhuhai-Macao
Bridge Hong Kong Link Road Environmental Monitoring & Audit (EM&A)
reports have also been reviewed. As these data only cover short
survey periods and there is no annual data available, they were not used in the
establishment of the habitat rating index in Section 3.3. However, these data provide further support
on the design of the marine travel route and SCZ. Results of EM&A reports
show that all grids with high CWD density pass through by the proposed travel route are covered by the proposed 15-knot SCZ.
Besides, the section of marine travel route with no speed restriction generally
crosses grids with no or low CWD density (see Figure 3‑10). The latest CWD data from HZMB EM&A are
consistent with the habitat rating index and support the design of the marine
travel route and 15-knot SCZ.
Figure 3‑10 Density of Chinese white dolphins from HZMB-HKLR Monitoring Reports
The EIA projected continued growth
in SkyPier HSF traffic up to 2030 (to approximately
130 annual average daily HSF movements) and impact assessments were based on
these increasing traffic levels. Even taking into account traffic growth,
the EIA determined that the route diversion and speed controlled zone proposed
would be able to reduce impacts from HSFs to acceptable levels in affected marine
waters. Further to receiving feedback on this aspect during the EIA
public comment period, AAHK has committed to an additional precautionary
measure of capping SkyPier HSF movements based on
historic operations data (i.e. an annual daily average of 99 movements), this
to be effective in the period before designation of the proposed marine park.
During the main ACE and ACE EIA
Sub-committee discussions on the 3RS EIA, members also recommended that AAHK
should further explore the feasibility of imposing a maximum daily cap on the
number of HSF leaving the SkyPier and imposing
further speed restrictions at different spots along the diverted marine route
after detailed study. Although the EP specifies exploring the feasibility of
the daily cap for HSFs leaving the SkyPier, the
annual daily average cap of 99 and the maximum daily cap being proposed in this
plan refer to HSF movements at SkyPier. One movement comprises a SkyPier
departure or an arrival.
As required in the EP, AAHK will cap the SkyPier HSF movements at an annual daily average of 99 prior to designation of the proposed marine park in addition to the route diversion and speed restrictions in high-density CWD areas. The commitment to an annual daily average of 99 SkyPier HSF movements has taken into account a number of operational considerations, for example expected seasonal fluctuations above and below the annual daily average and to allow some capacity for operations recovery after inclement weather events (e.g. typhoons) and expected peak demand periods during any year, for example Lunar New Year or the Golden Week holiday when very high traffic demand is expected. A further maximum daily movement cap has been explored. It is recognised that imposing an absolute cap on maximum daily movements at SkyPier may present a significant operational challenge in particular during busy periods each year for example the golden week holiday or to accommodate HSF service recovery in the aftermath of inclement weather events. In order to establish a reasonable maximum daily capping commitment, scheduled and actual HSF movements at SkyPier since 2010 have been reviewed.
The history of SkyPier HSF movements since 2010 shows that actual daily HSF movements only vary up and down slightly (within +/- 5 movements) from the annual average daily movements for the vast majority of days in any year. Yet there are rare occasions over this period when larger fluctuations have been experienced and these had to be handled. During this period the highest number of scheduled movements in any one day was 123, although actual movements on the day in question were a little below this. Over the period since 2010, days with HSF movements above 110 totalled less than 30. Thus, in order to allow similar levels of flexibility for SkyPier HSF operators as has previously been possible it is proposed to adopt 125 movements as the maximum daily movement cap in conjunction with the overall commitment to 99 annual daily average HSF movements. Setting this target will provide operational flexibility for handling any unexpected and rare operational challenges. It is again stressed that the proposal for a maximum daily cap of 125 movements does not alter the main commitment to 99 annual daily average HSF movements.
In order to ensure that the annual daily average HSF movements can be kept within the target of 99 per day – or 36,135 movements during one whole year (with 365 calendar days) - AAHK intends to work closely with SkyPier HSF Operators to ensure that during ‘normal’ operations, daily movements are slightly below the 99 target such that a buffer of extra movement slots develops that balances both the expected days when several extra movements above the 99 target will be experienced and to offset the very rare peak service days when more than 110 movements may need to be handled by HSF operators.
The annual daily average limit and the maximum daily movement cap would be implemented before the end of 2015 and will be in effect during the period before designation of the proposed Marine Park.