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 |
||||
|
June 2018 |
AMS1 |
39 |
10 – 85 |
381 |
500 |
|
AMS4 |
24 |
7 – 49 |
352 |
||
|
July 2018 |
AMS1 |
41 |
4 – 198 |
381 |
|
|
AMS4 |
28 |
10 – 132 |
352 |
||
|
August 2018 |
AMS1 |
34 |
4 – 79 |
381 |
|
|
AMS4 |
24 |
3 – 51 |
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 |
||||
|
June 2018 |
AMS1 |
19 |
13 – 25 |
170 |
260 |
|
AMS4 |
17 |
11 – 27 |
171 |
||
|
July 2018 |
AMS1 |
19 |
9 – 28 |
170 |
|
|
AMS4 |
13 |
9 – 18 |
171 |
||
|
August 2018 |
AMS1 |
17 |
13 – 21 |
170 |
|
|
AMS4 |
17 |
11 – 23 |
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 |
|||
|
June 2018 |
NMS1 |
69 |
65 – 72 |
75 dB(A) |
|
NMS4 |
62 |
55 – 64 |
||
|
July 2018 |
NMS1 |
67 |
61 – 70 |
|
|
NMS4 |
63 |
54 – 67 |
||
|
August 2018 |
NMS1 |
70 |
59 – 73 |
|
|
NMS4 |
60 |
54 – 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 June to August 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 193.34 km of survey effort was collected,
with 95.5% of the total survey effort being conducted under favourable
weather conditions (i.e. Beaufort Sea State 3 or below with good
visibility). The total survey
effort conducted on primary lines was 127.25 km, while the effort on secondary
lines was 66.09 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 June to August 2018,
a total of 35 groups
of 133
Chinese White Dolphins were sighted.
All except two
dolphin sightings
were made during on-effort search. Twenty-five on-effort
sightings were made on primary lines, while the other eight 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 June to August 2018 is
shown in Figure 1 of Appendix F. The dolphin groups were evenly
distributed across the WL survey area, with slightly higher concentration near
and to the north of Kai Kung Shan, near Peaked Hill and Fan Lau (Figure 1 of Appendix F). On the other hand, they appeared to
avoid the waters near Tai O Peninsula as well as the southern end of the WL
waters (Figure 1 of Appendix F).
4.12
Sighting distribution of
dolphins in the present quarter was somewhat similar to the one during the
baseline period in September to November 2011. However, there appeared to be fewer
dolphin sightings made in the northern portion of the WL survey are during the
present impact phase period when compared to the baseline period (Figure 1 of Appendix F).
4.13
Three of the 35 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 summer quarter of 2018, several dolphin groups
were also observed near the bridge alignment in NWL waters, which was
comparable to 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, which was also the case in the previous quarter. 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 may still be 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 summer quarters of 2015-17 were compared
with the one in 2018. Level of
dolphin occurrence throughout the WL waters during the summer period of 2018
was similar to the previous three years, but they appeared more often near the
HKLR09 alignment and near Kai Kung Shan in 2018 (Figure 3 of Appendix F).
Encounter
rate
4.16
During the present
three-month impact phase monitoring period (June – August 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 (June to August
2018)
|
Survey Area |
Dolphin Monitoring |
Encounter rate (STG) |
Encounter rate (ANI) |
|
Primary Lines Only |
Primary Lines Only |
||
|
West Lantau |
25.9 |
134.9 |
|
|
Set 2 (June 20th) |
19.5 |
58.4 |
|
|
Set 3 (July 10th) |
10.3 |
36.0 |
|
|
Set 4 (July 19th) |
19.5 |
39.0 |
|
|
Set 5 (August 2nd) |
9.3 |
101.9 |
|
|
Set 6 (August 9th) |
34.3 |
132.2 |
Table
4.7 Comparison of
average dolphin encounter rates from impact monitoring period (June to August
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) |
||
|
June –
August 2018 |
September-
November 2011 |
June –
August 2018 |
September-
November 2011 |
|
|
West Lantau |
19.78 ± 9.47 |
16.43± 7.70 |
83.71 ± 45.18 |
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 (June to August 2018) were the fourth
and third highest respectively during the entire construction period, and both
were also the highest in the past four years (Table 4 of Appendix F).
In fact, those encounter rates were noticeably higher than the baseline
ones recorded in 2011 (Table 4 of
Appendix F). Such dramatic
rebound in the present quarter should be continuously monitored in the upcoming
quarter, to confirm whether the increase in dolphin occurrence in WL survey
area is temporary or persistent.
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 21st quarter of the impact phase), the
p-value for the differences in average dolphin encounter rates of STG and ANI
were 0.517 and 0.361 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 Another comparison was made between the baseline
period and the 21 cumulative quarters in the impact phase, and the p-value for
the differences in average dolphin encounter rates of STG and ANI were 0.465
and 0.605 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 twenty individuals per group
in WL survey area during June to August 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 (June to August 2018)
and baseline monitoring period (September-November 2011)
|
|
Average Dolphin
Group Size |
|
|
June – August 2018 |
September – November 2011 |
|
|
West Lantau |
3.80 ± 3.73 (n = 35) |
3.63 ± 2.97 (n = 46) |
4.21
The
average dolphin group size in the WL region during the present quarter was
slightly higher than the one recorded during the three-month baseline period (Table 4.8). Among the 35 groups, 26 of them were
composed of only 1-4 dolphins, while there were seven groups in moderate size
with 5-9 dolphins, and two large groups with 11 and 20 animals respectively.
4.22
Distribution
of dolphins with larger group sizes (with five or more animals per group)
during June to August 2018 is shown in Figure
4 of Appendix F. With the
exception of a large group of 20 animals sighted to the north of the HKLR09
alignment, the other larger dolphin groups in the present impact phase period
were mainly distributed in the central and southern portions of the WL survey
area with slightly higher concentration to near Kai Kung Shan and Fan Lau. This was slightly different from the
baseline phase when the large dolphin groups were also concentrated near Tai O
Peninsula (Figure 4 of Appendix F).
Habitat
use
4.23
From June to August 2018, the
grids that recorded higher densities of dolphins were located near the HKLR09
alignment, near Kai Kung Shan, Peaked Hill and Fan Lau (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
slightly lower during the present impact phase monitoring period in summer
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, only three young
calves (all were unspotted juveniles) were sighted in the WL survey area. These young calves comprised only 2.3%
of all animals sighted, which was much lower than the percentage recorded
during the baseline monitoring period (6.6%). All three young calves occurred
at the southern end of the WL survey area during this quarter, and such
occurrence was very different from the baseline period when calf occurrence was
much more frequent and concentrated in the northern portion of WL waters near
Tai O Peninsula (Figure 7 of Appendix F).
Activities and associations with fishing
boats
4.26
During the three-month impact
monitoring period, three dolphin groups were engaged in feeding activities to
the north of HKLR09 alignment and between Kai Kung Shan and Tai O Peninsula
respectively (Figure 8 of Appendix F),
comprising 8.6% of the total number of dolphin sightings. This percentage was somewhat lower than
the percentage recorded during the baseline period (13.0%). In addition, two dolphin groups were engaged in socializing activities to
the north of HKLR09 alignment and near Kai Kung Shan respectively, while
another group was engaged in traveling activities to the west of Peaked Hill
near the territorial border (Figure 8 of
Appendix F). Distribution of different activities engaged by the dolphins
during the present impact phase monitoring period was quite different from the
one during the baseline period, when the main concentration of the feeding and
socializing activities occurred between Tai O Peninsula and Peaked Hill (Figure 8 of Appendix F). During the
three-month monitoring period, one of the 35 dolphin groups was associated with
an operating purse-seiner (Appendix II
of Appendix F).
Summary of photo-identification works
4.27
From June to August 2018, over 3,500 digital
photographs of Chinese White Dolphins were taken during the impact phase
monitoring surveys for the photo-identification work.
4.28
In total, 65 individuals sighted 80 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). The majority of these individuals were
re-sighted only once during the three-month period. However, there were a total of nine
individuals (NL269, NL279, NL330, WL68, WL137, WL218, WL245, WL267 and WL272)
being re-sighted twice, and another three individuals being re-sighted thrice
(NL212, WL98 and WL293) (Appendix III of
Appendix F).
4.29
Among the 65 identified individual dolphin, nine
of them (CH113, NL145, NL233, NL317, NL327, NL329, WL188, WL207 and WL251) were
also re-sighted in North Lantau waters during HKLR03/HKBCF monitoring surveys
during the same three-month period.
However, while some did show extensive movements across the HKLR09
alignment, a number of individuals actually just occurred near the alignment at
the juncture of NWL/WL survey areas to the west of the airport (e.g. CH113,
NL145, WL251).
4.30
Notably,
many individuals (e.g. NL49, NL98, NL123, NL236) were
consistently sighted in North Lantau waters in the past, but were re-sighted in
WL waters during the present quarterly period.
Individual range use
4.31
Ranging patterns of the 65 individuals identified
during the three-month study period were determined by fixed kernel method, as
shown in Appendix V of Appendix F.
4.32
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 the northern part of Lantau waters during the present quarterly
period (Appendix V of Appendix F).
Conclusion
4.33
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.
4.34
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
4.35
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.
4.36
The amount of wastes generated by the activities
of the Contract during the reporting month is shown in Appendix J.