4               Environmental monitoring Results

Air Quality Monitoring Results

 

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 2015

AMS1

32

14 – 181

381

500

AMS4

27

14 – 98

352

July 2015

AMS1

34

7 – 213

381

AMS4

43

11 – 279

352

August 2015

AMS1

48

14 – 207

381

AMS4

39

14 – 131

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 2015

AMS1

15

9 – 27

170

260

AMS4

21

5 – 39

171

July 2015

AMS1

42

21 – 74

170

AMS4

25

17 – 35

171

August 2015

AMS1

54

18 – 101

170

AMS4

53

23 – 103

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


Noise Monitoring Results

 

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 2015

NMS1

69

68 - 69

75 dB(A)

NMS4

62

54 – 64

July 2015

NMS1

70

67 – 71

NMS4

58

52 – 63

August 2015

NMS1

71

70 – 72

NMS4

52

51 – 53

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

 

Water Quality Monitoring Results

 

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.

 

Dolphin Monitoring (Line-transect Vessel Survey)

 

Summary of survey effort and dolphin sightings

 

4.8           During the period of June to August 2015, 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 199.77 km of survey effort was collected, with 86.2% 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 133.76 km, while the effort on secondary lines was 66.01 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 2015, a total of 27 groups of 116 Chinese White Dolphins were sighted.  All except one sightings were made during on-effort search.  Eighteen on-effort sightings were made on primary lines, while the other 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 2015 is shown in Figure 1 of Appendix F.  The dolphin groups were mainly clustered near Tai O Peninsula, Peaked Hill and Fan Lau.  It appeared that they have avoided the waters between Tai O Peninsula and Kai Kung Shan (Figure 1 of Appendix F).

 

4.12       Sighting distribution of dolphins in the present quarter was generally similar to the one during the baseline period, but with some subtle differences.  Dolphins occurred less frequently between Tai O Peninsula and Peaked Hill during the present impact phase period.  Moreover, two dolphin groups were sighted to the north of the HKLR09 alignment during the present quarter, where no dolphin was sighted during the baseline period (Figure 1 of Appendix F).

 

4.13       Two of the 27 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 summer quarters of 2013, 2014 and 2015 were also compared (Figure 3 of Appendix F).  Much fewer dolphins occurred between Tai O Peninsula and Kai Kung Shan, as well as around Fan Lau in 2015.  On the other hand, after a decline in dolphin usage to the north of Tai O Peninsula in 2014, their usage has rebounded in 2015.  Overall, there appeared to be fewer dolphins utilizing WL survey area in summer 2015 than during the previous two summer periods.

 

Encounter rate

 

4.15       During the three-month impact phase monitoring period (June – August 2015), 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 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 – August 2015) 

 

Survey Area

Dolphin Monitoring

Encounter rate (STG)
(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)

Primary Lines Only

Primary Lines Only

West Lantau

Set 1 (June 9th)

15.8

121.2

Set 2 (June 18th)

6.5

38.9

Set 3 (July 6th)

13.1

74.5

Set 4 (July 28th)

13.2

66.0

Set 5 (August 18th)

20.5

61.5

Set 6 (August 26th)

5.0

5.0

 

Table 4.7    Comparison of average dolphin encounter rates from impact monitoring period (June – August 2015) and baseline monitoring period (September-November 2011)

 

 

 

Encounter rate (STG)

(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 2015

September-  November 2011

June - August 2015

September-  November 2011

West Lantau

12.36 ± 5.81

16.43 ± 7.70

61.19 ± 38.63

60.50 ± 38.47

 

4.16       Notably, the dolphin encounter rates from the present summer quarter of 2015 was much lower than the ones recorded from previous summers of 2014 (ER(STG): 22.90 and ER(ANI): 101.41) and 2015 (ER(STG): 26.89 and ER(ANI): 94.75).  Such temporal trend should be continuously monitoring to detect any further decline, even though the Action or Limit Level has not been triggered under the Event and Action Plan.

 

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. tenth quarter of the impact phase), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.325 and 0.892 respectively.  Therefore, no significant difference in dolphin encounter rate was detected between the baseline period and the present quarter.

 

4.18       Another comparison was made between the baseline period and the cumulative quarters in the impact phase (i.e. first ten quarters of the impact phase), and the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.976 and 0.998 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 1-20 individuals per group in WL survey area between June to August 2015.  The average dolphin group size in the WL region during the present quarter was higher than the one recorded in the three-month baseline period (Table 4).  About half of the groups were composed of 1-2 dolphins, while there were nine groups with more than 5 animals per group, and two groups with more than 10 animals per group. 

 

Table 4.8    Comparison of average dolphin group sizes from impact monitoring period (June – August 2015) and baseline monitoring period (September-November 2011)

 

Average Dolphin Group Size

June – August 2015

September to November 2014

West Lantau

4.30 ± 4.28 (n = 27)

3.63 ± 2.97 (n = 46)

 

4.20     Distribution of dolphins with the larger groups during June to August 2015 is shown in Figure 4 of Appendix F.  These groups were scattered from the bridge alignment to Fan Lau waters with no particular concentration, and a number of these large groups were located along the western territorial boundary (Figure 4 of Appendix F). The distribution of larger dolphin groups was very different from the baseline period, when they mostly occurred to the northwest of Tai O Peninsula (near the bridge alignment) as well as near Kai Kung Shan and Peaked Hill (Figure 4 of Appendix F).

 

Habitat use

 

4.21     From June to August 2015, the most heavily utilized habitats by the dolphins were mainly found near Tai O Peninsula, Kai Kung Shan and Fan Lau, which is similar to the previous monitoring quarters (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 (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.

 

4.22     When compared with the habitat use pattern recorded during the baseline period, it appears that the overall dolphin densities were lower in West Lantau waters during the present impact phase period, especially the waters near Kai Kung Shan and Fan Lau.  Moreover, distribution of dolphins was patchier in the present impact phase quarter with a number of grids recorded the absence of dolphin sightings (Figure 6 of Appendix F).

 

Mother-calf pairs

 

4.23     During the three-month impact phase monitoring period, five unspotted juveniles (UJ) were sighted in WL survey area.  The young calves comprised 4.3% of all animals sighted, which was lower than the percentage recorded during the baseline monitoring period (6.6%). 

 

4.24     The five mother-calf pairs were sighted near the bridge alignment, Kai Kung Shan and Fan Lau (Figure 7 of Appendix F).  This was in stark contrast to the baseline period when calf occurrence was more frequent and concentrated near Tai O Peninsula at the northern portion of WL waters (Figure 7 of Appendix F).

 

Activities and associations with fishing boats

 

4.25     During the three-month impact monitoring period, three dolphin sightings were associated with feeding activities between near the HKLR09 bridge alignment and Fan Lau (Figure 8 of Appendix F), comprising 11.1% of the total number of dolphin sightings.  This percentage was very similar to the percentage recorded during the baseline period (13.0%).

 

4.26     Moreover, three dolphin sightings were associated with socializing activity near the HKLR09 bridge alignment, Peaked Hill and Fan Lau (Figure 8 of Appendix F), while no dolphin group was engaged in traveling or milling/resting activity during the present quarter.

 

4.27     Distribution of feeding and socializing activities during the present impact phase monitoring period was somewhat different from the one during the baseline period, with the main concentration of these activities occurred between Tai O and Peaked Hill during the baseline period.  On the contrary, the occurrence of these activities was more wide-spread in different parts of the WL survey area during the impact phase period (Figure 8 of Appendix F).

 

4.28     During the three-month monitoring period, only one of the 27 dolphin groups was associated with an operating purse-seiner near Fan Lau.

 

Summary of photo-identification works

 

4.29     From June to August 2015, over 2,500 digital photographs of Chinese White Dolphins were taken during the impact phase monitoring surveys for the photo-identification work.

 

4.30     In total, 64 individuals sighted 77 times altogether were identified (see summary table in Appendix III of Appendix F and photographs of identified individuals in Appendix IV of Appendix F.  Almost all identified individuals were sighted only once or twice during the three-month period, with the exception of three individuals (NL120, NL140 and WL214) being sighted thrice.

 

 

Individual range use

 

4.31     Ranging patterns of the 64 individuals identified during the three-month study period were determined by fixed kernel method, and are shown in Appendix V of Appendix F. 

 

4.32     Notably, a number of individual dolphins (NL136, NL210, NL242, NL261, NL280, NL284, NL295 and WL11) that primarily centered their range use in North Lantau were found extending their ranges to the southern part of West Lantau waters, further expanding their range use away from North Lantau waters (Appendix V of Appendix F). 

 

4.33     On the contrary, most individuals that primarily centered their range use in West Lantau were sighted within their normal range during the present quarterly period Appendix V of Appendix F).

 

Conclusion

 

4.34     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.

 

4.35     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.

 

Additional Land-based Dolphin Behaviour and Movement Monitoring

 

4.36     Additional land-based dolphin behavior and movement monitoring were conducted 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 (June to August 2015)

 

Date

Time

Weather

Number of Staff

Number of Dolphin Sighting

Beaufort

Visibility

03/06/15

09:12 - 14:43

2- 4

1

3

2

11/06/15

09:05 - 14:30

2

2

3

0

06/07/15

09:22 - 14:53

2

2-3

3

3

16/07/15

09:28 - 14:44

2

2

3

2

13/08/15

09:05 - 14:31

3

2

3

0

21/08/15

09:02 - 14:16

2-3

2

3

1

 

4.37     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.

 

Advice on the Solid and Liquid Waste Management Status

 

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.