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 |
||||
|
September 2013 |
AMS1 |
78 |
14 - 147 |
381 |
500 |
|
AMS4 |
104 |
18 - 215 |
352 |
||
|
October 2013 |
AMS1 |
131 |
55 - 234 |
381 |
|
|
AMS4 |
147 |
60 - 265 |
352 |
||
|
November 2013 |
AMS1 |
95 |
38 - 145 |
381 |
|
|
AMS4 |
123 |
24 - 658 |
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 |
||||
|
September 2013 |
AMS1 |
58 |
18 - 96 |
170 |
260 |
|
AMS4 |
59 |
25 - 92 |
171 |
||
|
October 2013 |
AMS1 |
96 |
40 – 156 |
170 |
|
|
AMS4 |
91 |
20 - 130 |
171 |
||
|
November 2013 |
AMS1 |
71 |
29 – 108 |
170 |
|
|
AMS4 |
65 |
29 - 99 |
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 |
Other
construction site nearby |
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 |
|||
|
September 2013 |
NMS1 |
68 |
57 – 72 |
75 dB(A) |
|
NMS4 |
60 |
53 – 63 |
||
|
October 2013 |
NMS1 |
69 |
67 – 70 |
|
|
NMS4 |
55 |
52 – 58 |
||
|
November 2013 |
NMS1 |
70 |
66 – 72 |
|
|
NMS4 |
61 |
57 – 64 |
||
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
near by operating vessels by other parties.
Summary of survey effort and dolphin
sightings
4.8
During the period of September
to November 2013, 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 191.51
km of survey effort was collected, with 84.8% 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 126.63 km, while the effort on secondary lines was 64.88
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 September to November
2013, a total of 37 groups of 101
Chinese White Dolphins were sighted.
All except five sightings were made during on-effort search.
Twenty-five on-effort sightings were made on primary
lines, while another seven 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 September to November
2013 is shown in Figure 1 of Appendix F. The dolphin groups were evenly distributed
throughout the WL survey area, with higher concentrations near Tai O Peninsula
and Fan Lau.
4.12
The sighting distribution of dolphins in the
present quarter was largely similar to the one during baseline period, except
that fewer dolphins were sighted near Kai Kung Shan and the offshore waters
along the territorial boundary during the present monitoring period
4.13
Notably, a few sightings were made in the vicinity
and along the western portion of the HKLR09 alignment in WL survey area.
It appeared that dolphins occurred as frequently in the impact phase monitoring
period as in the baseline monitoring period, and their distribution was not
affected by the HKLR09 construction activities in the present quarter.
Encounter rate
4.14
During the three-month impact phase
monitoring period, 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 September to November
2013 were also compared with the ones deduced from the baseline monitoring
period (September – November 2011) (Table
4.7).
4.15
In WL survey area, the average dolphin
encounter rates (both STG and ANI) in the present three-month study period were
both slightly higher than the ones recorded in the 3-month baseline period
respectively, indicating the dolphin usage during this impact phase monitoring
period in this survey area did not show any obvious change when compared to the
baseline phase.
Table 4.6 Dolphin encounter rates (sightings per 100 km of survey
effort) during the impact monitoring period (September - November 2013)
|
Survey Area |
Dolphin Monitoring |
Encounter rate (STG) |
Encounter rate (ANI) |
|
Primary Lines Only |
Primary Lines Only |
||
|
West Lantau |
34.9 |
94.8 |
|
|
Set 2
(September 19, 2013) |
35.5 |
112.6 |
|
|
Set 3 |
14.1 |
28.2 |
|
|
Set 4 |
19.0 |
71.1 |
|
|
Set 5 |
4.6 |
27.6 |
|
|
Set 6 |
14.9 |
29.8 |
Table 4.7 Comparison of average dolphin encounter rates from
impact monitoring period (September
- November 2013) 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) |
||
|
September - November 2013 |
September- November 2011 |
September - November 2013 |
September- November 2011 |
|
|
West Lantau |
20.51 ± 12.34 |
16.43 ± 7.70 |
60.68 ± 37.60 |
60.50 ± 38.47 |
(Note:
the encounter rates deduced from the baseline monitoring period have been
recalculated based only on the survey effort and on-effort sighting data made
along the primary transect lines under favourable
conditions)
4.16 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 (second quarter of the impact phase), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.508 and 0.993 respectively. Therefore, no significant difference in dolphin encounter rate was detected between the baseline period and the present quarter.
4.17 To facilitate the comparison with the AFCD long-term monitoring results, the encounter rates were also calculated for the present quarter (September-November 2013) using both primary and secondary survey effort. The encounter rates of sightings (STG) and dolphins (ANI) in WL were 17.9 sightings and 47.4 dolphins per 100 km of survey effort respectively.
Group size
4.18 Group size of Chinese White Dolphins ranged from 1-7 individuals per group in WL survey area between September and November 2013. The average dolphin group sizes from these three months were compared with the one deduced from the baseline period in September to November 2011, as shown in Table 4.8. The average dolphin group size in the WL region during September and November 2013 was much smaller than the ones recorded in the 3-month baseline period (Table 4.8). In fact, more than half of the dolphin groups were composed of 1-2 dolphins, and only five groups had more than 5 animals per group.
Table 4.8 Comparison of average dolphin group sizes from
impact monitoring period (September
- November 2013) and baseline monitoring
period (September-November 2011)
|
|
Average Dolphin Group
Size |
|
|
September-November 2013 |
September-November 2011 |
|
|
West Lantau |
2.73
± 1.74 (n = 37) |
3.63 ± 2.97 (n = 46) |
4.19 Distribution of dolphins with these five larger group sizes (more than 5 animals per group) during September through November 2013 is shown in Figure 2 of Appendix F. These groups were mostly sighted in the southern portion (i.e. between Tai O and Peak Hill), further away from the HKLR09 alignment (Figure 2 of Appendix F). This was different from the baseline period, when some of these dolphin groups also occurred near Tai O Peninsula closer to the bridge alignment.
Habitat use
4.20 From September to November 2013, the most heavily utilized habitats by the dolphins mainly concentrated near Tai O Peninsula, Kai Kung Shan, near Peaked Hill and Fan Lau (Figures 3a and 3b of Appendix F). However, it should be noted that the amount of survey effort collected in each grid during the three-month period was fairly low (6 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.
4.21 When compared with the habitat use pattern recorded during the baseline period, it appears that dolphin densities were much lower between the HKLR09 alignment and Tai O Peninsula during the present impact phase monitoring period (Figure 4 of Appendix F).
Mother-calf pairs
4.22 During the three-month impact phase monitoring period, only four unspotted juveniles (UJ) were sighted in WL survey area. These young calves comprised only 4.0% of all animals sighted, which was much lower to the percentage recorded during the baseline monitoring period (6.6%). As anthropogenic activities within the dolphin habitat can be more disturbing to the mother-calf pairs, their occurrence should be continuously monitored in the upcoming quarters to examine whether such diminished occurrence may be affected by the bridge construction.
4.23 The occurrence of these young calves were scattered in the central and southern portions of WL survey area with no particular concentration (Figure 5 of Appendix F). Such distribution was different from the baseline period, where more frequent occurrence of calves near Tai O Peninsula was found (Figure 5 of Appendix F).
Activities and
associations with fishing boats
4.24 A total of five dolphin sightings were associated with feeding respectively during the three-month impact monitoring period, comprising of 8.1% of the total number of dolphin sightings. This percentage was lower than the percentage recorded during the baseline period (13.0%). None of the sightings were associated with socializing activities. The low occurrence of these two important activities recorded in the present quarter is of concern, and should be continuously monitored in the upcoming quarters.
4.25 Distribution of dolphins engaged in the feeding activities during the three-month study period is shown in Figure 6 of Appendix F. These sightings were scattered in the middle portion of WL survey area with no particular concentration. This distribution pattern was similar to the baseline period, when most feeding activities were concentrated in the middle portion of the survey area between Tai O Peninsula and Kai Kung Shan (Figure 6 of Appendix F).
4.26 During the three-month period, only
one group of six dolphins was found to be associated with an operating purse-seiner, comprising of 2.7% of all dolphin groups. This was much lower than the percentage
recorded in baseline period (6.5%), and the very low percentage of fishing boat
association during the present and previous impact phase monitoring quarters was
likely related to the recent trawl ban being implemented in 2013 in Hong Kong
waters.
Summary of photo-identification
works
4.27 From September to November 2013, over 1,000 digital photographs of Chinese White Dolphins were taken during the impact phase monitoring surveys for the photo-identification work.
4.28 In total, 31 individuals sighted 39 times altogether were identified (see summary table in Appendix III of Appendix F and photographs of identified individuals in Appendix IV of Appendix F. Most identified individuals were sighted only once or twice during the three-month period, with the exception of three individuals being sighted thrice (CH108 and WL199).
4.29 During the three-month period, only one recognizable female, WL159, was sighted to be accompanied with her calf during her re-sighting.
Individual range use
4.30 Ranging patterns of the 31 individuals identified during the three-month study period were determined by fixed kernel method, and are shown in Appendix V of Appendix F.
4.31 Among these 31 individuals, many of them were sighted near the HKLR09 alignment (e.g. CH113, NL37, WL11) during the present impact monitoring period. Some of them were even sighted to the south and north of the bridge alignment within the 3-month period (e.g. NL296, WL15, WL46).
4.32 Notably, the ranging patterns of a few individuals (e.g. SL44, WL182) do not overlap with the HKLR09 alignment at all, but mostly located around the southwestern side of Lantau Island (Appendix V of Appendix F). Therefore, it is unlikely that the impact of HKLR09 construction activities will affect their range use during the impact phase.
Conclusion
4.33 During this quarter of dolphin monitoring, no adverse impact from the activities of the HKLR09 construction project on Chinese White Dolphins was noticeable from general observations, and the dolphin occurrence in West Lantau survey area remained the same as in the baseline period.
4.34 Nevertheless, dolphin usage in WL region should be continuously monitored, to examined whether it will be affected by the on-going construction activities in relation to the HZMB works
4.35 Additional land-based dolphin behavior and movement monitoring was conducted on 28th and 30th September 2013 in the reporting period. The progress of the monitoring is summarized in the Table 4.9.
Table 4.9 Progress
Record of Additional Land-based Dolphin Behaviour and
Movement Monitoring in
September 2013
|
Date |
Time |
Weather |
Number
of Staff |
Number
of Dolphin Sighting |
|
|
Beaufort |
Visibility |
||||
|
28/09/2013 |
08:59 - 15:00 |
2-4 |
3 |
3 |
1 |
|
30/09/2013 |
10:28 - 15:32 |
2-3 |
3.5 |
3 |
0 |
4.36
Detailed
monitoring methodology and results will be provided in a separate report after
the completion of full set of additional land-based dolphin behavior and
movement monitoring.
4.37
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.
4.38
The
amount of wastes generated by the activities of the Contract during the
reporting month is shown in Appendix J.