4.1
The monitoring results for 1-hour TSP and 24-hour TSP are summarized in Table 4.1 and 4.2 respectively. Graphical presentations of 1-hour and 24-hour TSP monitoring results
are shown in Appendices B and C respectively.
Table 4.1 Summary Table of 1-hour TSP Monitoring
Results during the Reporting Period
|
Month |
Monitoring Station |
Concentration (µg/m3) |
Action
Level, µg/m3 |
Limit
Level, µg/m3 |
|
|
Average |
Range |
||||
|
March 2018 |
AMS1 |
55 |
24 – 102 |
381 |
500 |
|
AMS4 |
50 |
21 – 97 |
352 |
||
|
April 2018 |
AMS1 |
70 |
0 – 105 |
381 |
|
|
AMS4 |
64 |
16 – 165 |
352 |
||
|
May 2018 |
AMS1 |
33 |
10 – 84 |
381 |
|
|
AMS4 |
26 |
1 – 64 |
352 |
||
Table 4.2 Summary
Table of 24-hour TSP Monitoring Results during the Reporting Period
|
Month |
Monitoring Station |
Concentration (µg/m3) |
Action
Level, µg/m3 |
Limit
Level, µg/m3 |
|
|
Average |
Range |
||||
|
March 2018 |
AMS1 |
42 |
29 – 53 |
170 |
260 |
|
AMS4 |
39 |
31 – 46 |
171 |
||
|
April 2018 |
AMS1 |
65 |
18 – 183 |
170 |
|
|
AMS4 |
49 |
15 – 119 |
171 |
||
|
May 2018 |
AMS1 |
25 |
14 – 49 |
170 |
|
|
AMS4 |
18 |
9 – 37 |
171 |
||
4.2
According to our field observations, the major dust source identified at
the designated air quality monitoring stations in the reporting period are as
follows:
Table
4.3 Observation at Dust
Monitoring Stations
|
Monitoring Station |
Major Dust Source |
|
AMS1 |
Exhaust from marine traffic |
|
AMS4 |
N/A |
4.3
The wind data monitoring results were attached in the Monthly EM&A
Reports
4.4
The noise monitoring results are summarized in Table 4.4. Graphical presentations of noise
monitoring are shown in Appendix D.
Table 4.4 Summary
Table of Noise
Monitoring Results during the Reporting Period
|
Month |
Monitoring Station |
Noise Level, Leq
(30min) dB(A) |
Limit
Level |
|
|
Average |
Range |
|||
|
March 2018 |
NMS1 |
71 |
66 – 72 |
75 dB(A) |
|
NMS4 |
62 |
59 – 64 |
||
|
April 2018 |
NMS1 |
69 |
66 – 70 |
|
|
NMS4 |
61 |
54 – 65 |
||
|
May 2018 |
NMS1 |
70 |
69 – 71 |
|
|
NMS4 |
60 |
56 – 63 |
||
Remark: +3dB(A) Façade correction included
4.5
According to our field observations, the major noise source identified
at the designated noise monitoring stations in the reporting period are as
follows:
Table 4.5 Observation
at Noise
Monitoring Stations
|
Monitoring Station |
Major Noise Source |
|
NMS1 |
Air
traffic & marine traffic noise |
|
NMS4 |
Air
traffic & marine traffic noise |
4.6
The graphical presentation of water quality at the monitoring stations
is shown in Appendix E.
4.7
Water quality impact sources during the water quality monitoring were
the construction activities of the Contract, nearby construction activities by
other parties and nearby operating vessels by other parties.
Summary
of survey effort and dolphin sightings
4.8
During the period of March to May 2018, six sets of systematic
line-transect vessel surveys were conducted to cover all transect lines in WL
survey area twice per month.
4.9
From these surveys, a total of 199.42 km of survey effort was collected,
with 81.3% of the total survey effort being conducted under favourable
weather conditions (i.e. Beaufort Sea State 3 or below with good
visibility). The total survey
effort conducted on primary lines was 129.72 km, while the effort on secondary
lines was 69.70 km. Survey effort
conducted on primary and secondary lines were both considered as on-effort
survey data. A summary table of the
survey effort is shown in Appendix I of
Appendix F.
4.10
During the six sets of monitoring surveys in March to May 2018, a total
of 22 groups of 88 Chinese White Dolphins were sighted. All 22 dolphin sightings were made
during on-effort search. Thirteen
on-effort sightings were made on primary lines, while the other nine on-effort
sightings were made on secondary lines.
A summary table of the dolphin sightings is shown in Appendix II of Appendix F.
Distribution
4.11
Distribution of dolphin
sightings made during HKLR09 monitoring surveys from March to May 2018 is shown
in Figure 1. The dolphin groups
were scattered evenly across the WL survey area with no particular concentration
(Figure 1 of Appendix F). However, they appeared to avoid the
waters near Tai O Peninsula as well as the southern and northern ends of the WL
waters (Figure 1 of Appendix F).
4.12
Sighting distribution of
dolphins in the present quarter was very different from the one during the
baseline period in September to November 2011. When compared to the baseline period,
dolphins occurred much less frequently in the waters around Tai O Peninsula,
Kai Kung Shan and Fan Lau as well as the offshore waters along the western
territorial boundary during the present impact phase period (Figure 1 of Appendix F).
4.13
Three of the 22 dolphin
groups were sighted near the HKLR09 alignment in WL survey area during the
present quarter (Figure 2 of Appendix F). When pooling the data from HKLR03 monitoring
surveys from the same spring quarter of 2018, no dolphins were observed near
the bridge alignment in NWL waters, which was very different from the dolphin
distribution in this same area during the baseline phase (Figure 2 of Appendix F).
4.14
Dolphins appeared to occur
more often near the HKLR09 alignment during the present quarterly period. As the disturbance arisen from the
HKLR09 construction activities on the dolphins have been completed, dolphins
may start to utilize the waters in the vicinity of the bridge alignment. However, it is premature to conclude
that the potential obstruction from the permanent physical structure of the
bridge piers does not occur any more, and this critical issue should be continuously
monitored in the upcoming quarters through boat surveys and land-based
theodolite tracking surveys.
4.15
Distribution patterns of
dolphin sightings in the past three spring quarters of 2015-17 were compared
with the one in 2018. Level of
dolphin occurrence throughout the WL waters during the spring period of 2018
was similar to the previous three years, but they appeared more often near the
HKLR09 alignment and less in the central portion of WL survey area in 2018 (Figure 3 of Appendix F).
Encounter
rate
4.16
During the present
three-month impact phase monitoring period (March – May 2018), the encounter
rates of Chinese White Dolphins deduced from the survey effort and on-effort
sighting data from the primary transect lines under favourable
conditions (Beaufort 3 or below) from West Lantau survey area are shown in Table 4.6. The
average encounter rates deduced from the six sets of surveys from the present
quarter were also compared with the ones deduced from the baseline monitoring
period (September – November 2011) (Table 4.7).
Table
4.6 Dolphin
encounter rates (sightings per 100 km of survey effort) during the impact
monitoring period (March to May 2018)
|
Survey Area |
Dolphin Monitoring |
Encounter rate (STG) |
Encounter rate (ANI) |
|
Primary Lines Only |
Primary Lines Only |
||
|
West Lantau |
13.4 |
26.7 |
|
|
Set 2 (March 15th) |
4.7 |
14.1 |
|
|
Set 3 (April 6th) |
15.6 |
62.4 |
|
|
Set 4 (April 13th) |
13.7 |
63.9 |
|
|
Set 5 (May 2nd) |
19.8 |
108.7 |
|
|
Set 6 (May 14th) |
0.0 |
0.0 |
Table 4.7 Comparison of average dolphin
encounter rates from impact monitoring period (March to May 2018) and baseline
monitoring period (September-November 2011)
|
|
(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) |
||
|
March –
May 2018 |
September- November 2011 |
March –
May 2018 |
September- November 2011 |
|
|
West Lantau |
11.18
± 7.37 |
16.43±
7.70 |
45.95
± 40.07 |
60.50±
38.47 |
4.17
Notably,
the encounter rates of dolphin sightings (ER(STG)) and encounter rates of
dolphins (ER(ANI)) in the present quarter (March to May 2018) has rebounded
from the lowest level in the past four quarterly period, and was higher than
the previous two spring periods (Table 4
of Appendix F). Nevertheless,
the quarterly encounter rate in spring 2018 was still well below the baseline
level, and should still be closely monitored in the upcoming quarters.
4.18
A one-way ANOVA was conducted
to examine whether there were any significant differences in the average
encounter rates between the baseline and impact monitoring periods. For the comparison between the baseline
period and the present quarter (i.e. the 20th quarter of the impact phase), the
p-value for the differences in average dolphin encounter rates of STG and ANI
were 0.255 and 0.536 respectively.
Therefore, if the alpha value is set at 0.05, significant difference was
not detected between the baseline period and the present quarter in both
encounter rates of STG and ANI.
4.19
Another comparison was made
between the baseline period and the 20 cumulative quarters in the impact phase,
and the p-value for the differences in average dolphin encounter rates of STG
and ANI were 0.419 and 0.545 respectively.
As a result, no significant difference was found in the dolphin
encounter rates between the baseline period and the cumulative quarters in the
impact phase.
Group
size
4.20
Group
size of Chinese White Dolphins ranged from one to ten individuals per group in WL
survey area during March to May 2018. The
average dolphin group size for the three-month period was compared with the one
deduced from the baseline period in September to November 2011, as shown in Table 4.8.
Table 4.8 Comparison of average dolphin
group sizes from impact monitoring period (March to May 2018) and baseline
monitoring period (September-November 2011)
|
|
Average Dolphin Group
Size |
|
|
March-May 2018 |
September – November 2011 |
|
|
West Lantau |
4.00 ± 2.53 (n = 22) |
3.63 ± 2.97 (n = 46) |
4.21
The
average dolphin group size in the WL region during the present quarter was a
little higher than the one recorded during the three-month baseline period (Table 4.8). Among the 22 groups, 16 of them were composed
of only 1-4 dolphins, while there were five groups in moderate size with 5-9
dolphins, and one large group with 10 animals.
4.22
Distribution
of dolphins with larger group sizes (with five or more animals per group)
during March to May 2018 is shown in Figure 4 of Appendix F. The
larger dolphin groups in the present impact phase period was mainly distributed
in the central portion of the WL survey area with no particular concentration,
which was slightly different from the baseline phase when the large dolphin
groups were more concentrated near Tai O Peninsula and Kai Kung Shan (Figure 4 of Appendix F).
Habitat
use
4.23
From From March to May 2018,
the grids that recorded higher densities of dolphins were located near the
HKLR09 alignment, between Tai O Peninsula and Kai Kung Shan, and 1-2 kilometers
to the west of Peaked Hill (Figures 5a & 5b of Appendix F). However, it should be cautioned that the
amount of survey effort collected in each grid during the three-month period was fairly low (six
units of survey effort for most grids), and therefore the habitat use pattern
derived from the three-month dataset should be treated with caution. A more complete picture of dolphin
habitat use pattern will be presented when more survey effort for each grid
will be collected throughout the impact phase monitoring programme.
4.24
When compared with the habitat
use pattern recorded during the baseline period in September-November 2011, it
appears that the overall dolphin occurrence was lower during the present impact
phase monitoring period in spring 2018, especially near the Tai O Peninsula (Figure 6 of Appendix F).
Mother-calf
pairs
4.25
During the three-month impact phase monitoring period, no mother-calf
pair was observed at all among the 22 dolphin groups.
Activities
and associations with fishing boats
4.26
During the three-month impact
monitoring period, none of the 22 dolphin groups were engaged in feeding,
socializing, traveling or resting/milling activity. Moreover, none of the 22 dolphin groups
was associated with any operating fishing vessel.
Summary
of photo-identification works
4.27
From March to May 2018, over 2,500 digital
photographs of Chinese White Dolphins were taken during the impact phase
monitoring surveys for the photo-identification work.
4.28
In total, 40 individuals sighted 48 times
altogether were identified (see the summary table in Appendix III of Appendix F and photographs of identified
individuals in Appendix IV of Appendix F). Most of these individuals were
re-sighted only once during the three-month period, with the exception of five
individuals (CH113, WL94, WL216, WL260 and WL291) being re-sighted twice, and
one individual being re-sighted four times (WL79) (Appendix III of Appendix F).
4.29
Among the 40 identified individual dolphin, three
of them (NL46, NL269 and WL179) were also re-sighted in North Lantau waters
during HKLR03/HKBCF monitoring surveys in the same three-month period, showing
some level of individual movements across the HKLR09 bridge alignment
Individual
range use
4.30
Ranging Ranging
patterns of the 40 individuals identified during the three-month study period
were determined by fixed kernel method, as shown in Appendix V of Appendix F.
4.31
As in previous monitoring quarters, the majority
of identified individuals that primarily centered their range use in West
Lantau were still sighted within their normal ranges during the present
quarterly period, while none of them has extended their range use from WL
waters to NWL waters during the quarterly period (Appendix V of Appendix F).
Conclusion
4.32
During the present quarter of
dolphin monitoring, no adverse impact from the activities of the HKLR09
construction project on Chinese White Dolphins was noticeable from general
observations.
4.33
Nevertheless, the dolphin usage
in WL region should be continuously monitored, to further examine whether it
has been significantly affected by the on-going construction activities in
relation to the HZMB works.
Advice
on the Solid and Liquid Waste Management Status
4.34
The Contractor was advised to minimize the wastes
generated through the recycling or reusing. All mitigation measures stipulated
in approved waste management plan shall be fully implemented.
4.35
The amount of wastes generated by the activities
of the Contract during the reporting month is shown in Appendix J.