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 2017 |
AMS1 |
89 |
39 – 193 |
381 |
500 |
|
AMS4 |
74 |
22 – 198 |
352 |
||
|
April 2017 |
AMS1 |
65 |
20 – 115 |
381 |
|
|
AMS4 |
62 |
24 – 146 |
352 |
||
|
May 2017 |
AMS1 |
109 |
30 – 323 |
381 |
|
|
AMS4 |
115 |
41 – 291 |
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 2017 |
AMS1 |
48 |
8 – 86 |
170 |
260 |
|
AMS4 |
81 |
35 – 163 |
171 |
||
|
April 2017 |
AMS1 |
43 |
16 – 73 |
170 |
|
|
AMS4 |
57 |
22 – 104 |
171 |
||
|
May 2017 |
AMS1 |
44 |
13 – 92 |
170 |
|
|
AMS4 |
64 |
29 – 118 |
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 2017 |
NMS1 |
65 |
61 – 68 |
75 dB(A) |
|
NMS4 |
59 |
57 – 61 |
||
|
April 2017 |
NMS1 |
66 |
62 – 68 |
|
|
NMS4 |
55 |
50 – 58 |
||
|
May 2017 |
NMS1 |
69 |
63 – 72 |
|
|
NMS4 |
65 |
53 – 67 |
||
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
2017, 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 193.77 km of survey effort was collected,
with 89.4% 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 126.92 km, while the effort on secondary lines was 66.85 km.
Survey effort conducted on primary and secondary lines were both
considered as on-effort survey data. 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
2017, a total of
17 groups of 63 Chinese White Dolphins were sighted. All except five dolphin sightings were made during on-effort search. Nine on-effort sightings were made on primary
lines, while the other three on-effort sightings were made on secondary
lines. Summary table of the dolphin
sightings is shown in Appendix II of
Appendix F.
Distribution
4.11
Distribution of
dolphin sightings made during monitoring surveys in March to May 2017 is shown
in Figure 1 of Appendix F. The dolphin groups were mostly
distributed in the central portion of the survey area (i.e. between Tai O
Peninsula and Peaked Hill) during the quarterly period (Figure 1 of Appendix F). On the contrary, they did not occurr in the northern section of the survey area near
HKLR09 alignment, and only a few sightings were made at the southern section
near Fan Lau (Figure 1 of Appendix F).
4.12
Sighting
distribution of dolphins in the present quarter was quite 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 to the north of Tai O Peninsula,
but more frequently in waters between Peaked Hill and Fan Lau during the
present impact phase period (Figure 1 of Appendix F).
4.13
None of the 17
dolphin groups was sighted near the HKLR09 alignment in WL survey area during
the present quarter (Figure 2 of Appendix F).
4.14
Distribution
patterns of dolphin sightings in the past three winter quarters of 2014-16 were
also compared with the one in 2017. Such distribution patterns were similar
across the four-year period, and the only obvious difference was their
infrequent occurrence in the southern portion of the survey area in 2017 in
comparison to the previous years (Figure
3 of Appendix F).
Encounter rate
4.15
During the
present three-month impact phase monitoring period (March to May 2017), 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-May 2017)
|
Survey
Area |
Dolphin
Monitoring |
Encounter rate
(STG) |
Encounter rate
(ANI) |
|
Primary Lines
Only |
Primary Lines
Only |
||
|
West
Lantau |
5.6 |
11.2 |
|
|
Set 2 (March
13th) |
4.7 |
4.7 |
|
|
Set 3 (April 5th) |
0.0 |
0.0 |
|
|
Set 4 (April 13th) |
14.9 |
64.5 |
|
|
Set 5 (May 8th) |
9.7 |
19.4 |
|
|
Set 6 (May 19th) |
9.7 |
29.1 |
Table 4.7 Comparison
of average dolphin encounter rates from impact monitoring period (March to May 2017) 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 2017 |
September- November 2011 |
March –May 2017 |
September- November 2011 |
|
|
West Lantau |
7.43± 5.13 |
16.43± 7.70 |
21.48± 23.49 |
60.50± 38.47 |
4.16
Notably, the
encounter rates of dolphin sightings (ER(STG)) and
encounter rates of dolphins (ER(ANI)) for the present spring quarter of 2017 dropped
to the lowest since impact phase monitoring commenced in spring 2013, and were
much lower than the baseline level (Table
4 of Appendix F). Moreover, the Action Level under the Event and Action
Plan for this quarter was triggered for the first time during the four-year
impact phase monitoring period. It is critical to continuously monitor such
temporal trend, as the dolphin usage continued to diminish in recent quarters
even though the HKLR09 construction works have been completed in 2016.
4.17
4.17 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. fifteenth quarter of the impact
phase), the p-value for the differences in average dolphin encounter rates of
STG and ANI were 0.038 and 0.0600 respectively. Therefore, if the alpha value is set at
0.05, significant difference in encounter rates of STG was detected between the
baseline period and the present quarter, but not for the encounter rates of
ANI.
4.18
Another
comparison was made between the baseline period and the 16 cumulative quarters
in the impact phase, and the p-value for the differences in average dolphin
encounter rates of STG and ANI were 0.594 and 0.741 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
4.19
Group size of Chinese White Dolphins
ranged from 1-13 individuals per group in WL survey area during March to May
2017. 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 – May 2017) and baseline monitoring period
(September-November 2011)
|
|
Average Dolphin Group Size |
|
|
March – May 2017 |
September – November 2011 |
|
|
West Lantau |
3.71 ± 2.95 (n = 17) |
3.63 ± 2.97 (n = 46) |
4.20
The average
dolphin group size in the WL region during the present
quarter was slightly higher than the one recorded in the three-month
baseline period (Table 4.8). Among the 17 groups, 13 of them were
composed of only 1-4 dolphins, while there were three groups in moderate size
with 5-7 animals per group, and one large group with 13 animals.
4.21
Distribution of
dolphins with the larger groups during March to May 2017 is shown in Figure 4 of Appendix F. The three medium-sized group of 5-7
animals were clustered near Kai Kung Shan and Peaked Hill in the central
portion of the survey area, while the one large group of 13 animals was sighted
near Fan Lau (Figure 4 of Appendix F).
4.22
Distribution of
the larger dolphin groups in the present impact phase period was quite
different from the baseline period, when these groups were sighted more often
near Tai O Peninsula and Yi O (Figure 4
of Appendix F).
Habitat use
4.23
From March to
May 2017, the grids that recorded higher densities of dolphins were found near
Kai Kung Shan, while the waters to the southwest of Tai O Peninsula was also
moderately used by them (Figures 5a and 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 high density grids of dolphins
were much less evenly distributed in the present impact phase monitoring
period, and the overall dolphin densities were much lower in certain areas such
as the waters just to the south of the HKLR09 alignment and near Fan Lau (Figure 6 of Appendix F).
Mother-calf pairs
4.25
During the
three-month impact phase monitoring period, no young calf was sighted at all
among the 17 groups of dolphins. In
fact, this was the second consecutive quarters with no calf occurrence recorded
in WL waters.
Activities and associations with
fishing boats
4.26
During the
three-month impact monitoring period, only one dolphin group was engaged in
feeding activity near Fan Lau (Figure 7
of Appendix F), comprising 5.9% of the total number of dolphin
sightings. Such percentage was much
lower than the one recorded during the baseline period (13.0%).
4.27
On the other
hand, no dolphin group was engaged in socializing, traveling or resting
activity during the present quarter (Figure
8 of Appendix F).
4.28
Distribution of
different activities during the present impact phase monitoring period was very
different from the one during the baseline period, when the feeding activities
were much more frequent and located in the central portion of the WL survey
area (Figure 7 of Appendix F).
4.29
During the
three-month monitoring period, four of the 17 dolphin groups was associated with
any operating fishing vessel.
Summary of photo-identification works
4.30
From March to
May 2017, over 2,500 digital photographs of Chinese White Dolphins were taken
during the impact phase monitoring surveys for the photo-identification work.
4.31
In total, 36
individuals sighted 45 times altogether were identified (see summary table in Appendix III of Appendix F and
photographs of identified individuals in Appendix
IV of Appendix F). The majority
of them were sighted only once or twice during the three-month period, while three
individuals (WL66, WL79 & WL211) were re-sighted thrice during the
quarterly period (Appendix III of Appendix
F).
Individual range use
4.32
Ranging patterns
of the 36 individuals identified during the three-month study period were
determined by fixed kernel method, as shown in Appendix V of Appendix F.
4.33
As in previous
monitoring quarters, a few individual dolphins (NL226, NL259) that primarily centered
their range use in North Lantau in the past were found extending their ranges
to West Lantau waters (but to the north of the HKLR09 alignment), with some
shifts and expansions of their range use away from North Lantau waters (Appendix V of Appendix F).
4.34
On the contrary,
the majority of the identified individuals that primarily centered their range
use in West Lantau were still sighted within their normal ranges during the
present quarterly period (Appendix V of Appendix
F).
Conclusion
4.35
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.
4.36
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.
4.37
There was an
Action Level exceedance of dolphin monitoring for the quarterly monitoring data
(between March to May 2017). According to the investigation
report(Appendix
K), the exceedance is considered not due to the Contract.
4.38
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.
4.39
The amount of
wastes generated by the activities of the Contract during the reporting month
is shown in Appendix J.