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 2017 |
AMS1 |
25 |
7 – 71 |
381 |
500 |
|
AMS4 |
27 |
10 – 129 |
352 |
||
|
July 2017 |
AMS1 |
22 |
0 – 109 |
381 |
|
|
AMS4 |
26 |
9 – 66 |
352 |
||
|
August 2017 |
AMS1 |
51 |
0 – 279 |
381 |
|
|
AMS4 |
38 |
1 – 201 |
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 2017 |
AMS1 |
15 |
5 – 27 |
170 |
260 |
|
AMS4 |
25 |
0.2 – 47 |
171 |
||
|
July 2017 |
AMS1 |
12 |
10 – 15 |
170 |
|
|
AMS4 |
25 |
17.9 – 49 |
171 |
||
|
August 2017 |
AMS1 |
25 |
10 – 55 |
170 |
|
|
AMS4 |
18 |
2 – 48 |
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 2017 |
NMS1 |
68 |
59 – 71 |
75 dB(A) |
|
NMS4 |
58 |
57 – 59 |
||
|
July 2017 |
NMS1 |
69 |
65 – 71 |
|
|
NMS4 |
58 |
53 – 60 |
||
|
August 2017 |
NMS1 |
70 |
62 – 74 |
|
|
NMS4 |
62 |
53 – 66 |
||
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 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 197.83 km of survey effort was collected, with 83.2% 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 130.09 km, while the effort on secondary lines was 67.74 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 June
to August 2017, a total of 21 groups of 59 Chinese White Dolphins were sighted. All 21 dolphin
sightings were made during on-effort search. Eleven on-effort sightings were made on primary lines, while the other ten 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 June to August 2017 is shown in Figure 1 of Appendix F.
The dolphin groups were evenly distributed throughout the WL survey area
with no particular concentration (Figure
1 of Appendix F). However, they appeared to occur much more often in the
inshore waters during the present quarterly period, and no dolphin was sighted
at the northern and southern ends of the survey area (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 to the
north of Tai O Peninsula and in the offshore waters during the present impact
phase period (Figure
1 of Appendix
F).
4.13
None of the 21 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 (June to August 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 (June to
August 2017)
|
Survey Area |
Dolphin Monitoring |
Encounter rate (STG) |
Encounter rate (ANI) |
|
Primary Lines Only |
Primary Lines Only |
||
|
West Lantau |
16.0 |
37.3 |
|
|
Set 2 (June 21st) |
4.7 |
28.3 |
|
|
Set 3 (July 4th) |
9.3 |
28.0 |
|
|
Set 4 (July 13th) |
11.1 |
22.2 |
|
|
Set 5 (August 8th) |
0.0 |
0.0 |
|
|
Set 6 (August 14th) |
11.8 |
23.7 |
Table 4.7 Comparison of average dolphin
encounter rates from impact monitoring period (June to August 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) |
||
|
June –August
2017 |
September- November 2011 |
June –August
2017 |
September- November 2011 |
|
|
West Lantau |
8.83±
5.66 |
16.43±
7.70 |
23.25±
12.54 |
60.50±
38.47 |
4.16
Notably, after dropping to the lowest in the
previous quarterly period since the impact phase monitoring commenced in spring
2013, the encounter rates of dolphin sightings (ER(STG))
and encounter rates of dolphins (ER(ANI)) for the present summer quarter of
2017 remained at a relatively low level, and were much lower than the baseline
level (Table 4 of Appendix F). Moreover,
the Action Level under the Event and Action Plan was triggered for the second
consecutive quarter. It is critical
to continuously monitor such temporal trend, as the dolphin usage continued to
diminish in recent quarters even when the HKLR09 marine construction works have
already been completed in 2016.
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. seventeenth quarter of the impact phase),
the p-value for the differences in average dolphin encounter rates of STG and
ANI were 0.080 and 0.048 respectively.
Therefore, if the alpha value is set at 0.05, significant difference in
encounter rates of ANI was detected between the baseline period and the present
quarter, but not for the encounter rates of STG.
4.18
Another comparison was made between the baseline
period and the 17 cumulative quarters in the impact phase, and the p-value for
the differences in average dolphin encounter rates of STG and ANI were 0.541
and 0.671 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 1-9 individuals per group in WL survey
area during June to August 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 (June-August 2017) and baseline
monitoring period (September-November 2011)
|
|
Average Dolphin Group
Size |
|
|
June – August 2017 |
September – November 2011 |
|
|
West Lantau |
2.81 ± 2.06 (n = 21) |
3.63 ± 2.97 (n = 46) |
4.20
The average dolphin group size in the WL region
during the present quarter was lower than the one
recorded in the three-month baseline period (Table 4.8). Among the 21
groups, 16 of them were composed of only 1-3 dolphins, while there were four
groups in moderate size with 5-9 animals per group.
4.21
Distribution of dolphins with larger group sizes
(with five or more animals per group) during June to August 2017 is shown in Figure 4 of Appendix F. The four medium-sized group of 5-9
animals were clustered between Peaked Hill and Fan Lau in the southern portion
of the WL survey area (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 in the
central and northern portions of the survey area (Figure 4 of Appendix F).
Habitat
use
4.23
From June to August 2017, the grids that recorded
higher densities of dolphins were found near Tai O Peninsula, Kai Kung Shan, Peaked
Hill and Fan Lau (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 offshore waters to the west of Tai O
Peninsula and Peaked Hill (Figure 6 of Appendix
F).
Mother-calf
pairs
4.25
During the three-month impact phase monitoring
period, six young calves (all were unspotted juvenile) were sighted in WL
survey area. These young calves comprised
10.2% of all animals sighted, which was higher than the percentage recorded
during the baseline monitoring period (6.6%).
Activities
and associations with fishing boats
4.26
During the three-month impact monitoring period,
none of the dolphin group was observed to be engaged in feeding, socializing, traveling
or milling/resting activity during the present quarter.
4.27
Moreover, none of the 21 dolphin groups was
associated with any operating fishing vessel during the quarterly period.
Summary
of photo-identification works
4.28
From June to August 2017, over 2,000 digital
photographs of Chinese White Dolphins were taken during the impact phase
monitoring surveys for the photo-identification work.
4.29
In total, 32 individuals sighted 38 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 them were sighted only
once during the three-month period, while six individuals (CH105, CH113, WL79,
WL124, WL179 and WL277) were re-sighted twice (Appendix III of Appendix F).
Individual
range use
4.30
Ranging patterns of the 32 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, a few individual
dolphins (NL80, NL202, NL224 and NL236) that primarily centered their range use
in North Lantau in the past were found extending their ranges to West Lantau
waters, with some shifts and expansions of their range use away from North
Lantau waters (Appendix V of Appendix F).
4.32
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
4.33
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.
4.35
There was an Action Level exceedance of dolphin
monitoring for the quarterly monitoring data (between June
to August 2017). According to the investigation report(Appendix K), the exceedance is
considered not due to the Contract.
4.36
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.
4.37
The amount of wastes generated by the activities
of the Contract during the reporting month is shown in Appendix J.