9               ECOLOGICAL MONITORING

Monitoring of Measures to Minimise Disturbance to Water Birds in Ng Tung River, Sheung Yue River, Shek Sheung River and Long Valley

Monitoring Requirements and Protocol

9.1         As required under Section 12.3.2.5 of the Updated EM&A Manual, where development under the NDAs project is undertaken within 200m (the maximum distance at which it is predicted there may be some disturbance, and hence a reduction in numbers of large waterbirds) of Sheung Yue River and Long Valley, weekly transect at both high and low tides should be followed (It is considered high tide when the tidal levels are above 1.5m and low tide when the tidal levels are below 1.5m at Tsim Bei Tsui Station).

9.2         The purpose of the survey is to identify and enumerate all bird species utilizing the river channels and Long Valley Nature Park (LVNP) and identify any sources of actual or potential disturbance to birds due to construction activities throughout the construction period according to the methodology specified in Table 12.1 in the Updated EM&A Manual.

9.3         Monitoring in Long Valley followed the methodology adopted by the regular HKBWS bird monitoring programme in order to obtain comparable results and a complete coverage of the area in the shortest possible time.

Monitoring Frequency

9.4         High tide and low tide avifauna monitoring was required to be carried out on a weekly basis. Additional night-time avifauna monitoring in Long Valley was required to be carried out twice monthly from September to April.

Date of avifauna monitoring:

4, 7, 11, 15, 18, 21, 27 and 28 December 2023

Date of night-time monitoring:

11 and 18 December 2023

 

Monitoring Location

9.5         The avifauna monitoring was carried out at Ng Tung River, Sheung Yue River and Long Valley in the reporting month according to the construction programme. The transect routes in the reporting month were as follows:

       T1. Ng Tung River

       T2. Ng Tung River

       T3. Sheung Yue River

       T5. Long Valley

 

9.6         As the sensitive receivers (large waterbirds) were easily visible, the transect route only needed to follow one bank of the rivers.

9.7         The location of Transects T1, T2, T3 and T5 is shown in Figure 9 for reference.


 

Monitoring Parameters

9.8         The monitoring parameters and survey methodology for each transect are described below:

       Abundance of birds

       Types of habitat of which birds in use

       Notable bird behaviours such as roosting, feeding, nesting and presence of juveniles

       Birds heard through birdcalls that could not be located were marked as “heard”, while birds flying over the survey area were marked as “flight”. Species of conservation significance were specified.

9.9         Other information at the time of survey such as weather condition, tidal condition, tide level and noticeable natural or anthropogenic activities were documented.

9.10     For Avifauna survey, Ornithological nomenclature would make reference to The Avifauna of Hong Kong (Carey et al. 2001), The Birds of Hong Kong and South China (Viney et al. 2005), and the most recent updated list from other sources (e.g. Hong Kong Bird Watching Society).

Monitoring Results

9.11     In total, 78 species of birds were recorded during the bird surveys within assessment area. Among the recorded birds, there were 31 species of waterbirds. The detailed list of waterbirds and all recorded birds are shown in Appendices L1m and L1n respectively.

9.12     Among the four transects, transect T5 had a higher species diversity and abundance due to its diverse habitat types within Long Valley. Species such as Ardeola bacchus and Egretta garzetta were commonly found roosting and foraging at wetland habitats such as agricultural lands and shallow water habitats.

9.13     Along transect T5 in Long Valley, species with conservation interest such as Himantopus himantopus, which is a passage migrant, was commonly observed in shallow water habitats.

9.14     Construction works were observed in T5 in the reporting month.

9.15     Transect T3 was conducted along Sheung Yue River. Bird species such as Ardeola bacchus and Egretta garzetta were commonly observed feeding and roosting on the river bank and river bed. Construction works were observed beside Sheung Yue River.

9.16     Transects T1 and T2 are located at Ng Tung River. Ardeola bacchus and Egretta garzetta were commonly found feeding and roosting along the Ng Tung River. Fishing activities were observed at both T1 and T2. Potential anthropogenic sources of disturbance observed along T1 and T2 including the usage of remote control boats.

9.17     Avifauna monitoring in construction phase was conducted during the reporting month and the detailed results are attached in Appendix L1.

9.18     Table 9.1 summarises the avifauna monitoring results during the reporting month.

 


 

Table 9.1     Summary Table of Avifauna Monitoring Results to Corresponding Action and Limit Levels.

Monitoring Parameter

Result in Reporting Month

Baseline Level in Corresponding Month

Action Level

Limit Level

Mean abundance of large water birds* using Ng Tung River, Sheung Yue River and Shek Sheung River

57

34

24

17

Mean abundance of Ardeola bacchus using Ng Tung River, Sheung Yue River and Shek Sheung River

14.5

11

7

5

Mean Abundance of Bird recorded in LVNP

1438.5

901

631

451

Mean Abundance of Ardeola bacchus recorded in LVNP

21

15

11

8

Environmental disturbance and damage from activities in LVNP

-

-

Activity likely to cause unacceptable environmental disturbance or damage noted in LVNP.

Activity causing unacceptable environmental disturbance or damage noted in LVNP.

*Note

Large Waterbirds includes:

Ardea alba, Ardea cinerea, Egretta eulophotes, Egretta garzetta, Ardea intermedia and Phalacrocorax carbo

 

9.19     No Action or Limit Level exceedance in avifauna monitoring was recorded during the reporting month.

Monitoring of Measures to Minimise Impacts to Ma Tso Lung Stream and Siu Hang San Tsuen Stream, and Long Valley

Monitoring Requirements and Protocol

9.20     As required under Section 12.3.2.14 of the Updated EM&A Manual, aquatic faunal monitoring should be carried out during the construction phase.

9.21     Larger organisms such as fish should be monitored by direct counting, while kick-netting and sweep-netting should be used for invertebrate sampling. There should be three replicates for invertebrate sampling at each sampling point. For kick-netting, the net should be placed with the opening facing the water current, and the substrate should be disturbed by kicking to dislodge organisms from the stream bed. Sweep-netting should be conducted when kick-netting is not feasible, such as in area with no water current. Small organisms that could not be identified with naked eye should be brought to the laboratory for identification under the dissecting microscope.

Monitoring Frequency

9.22     Quantitative aquatic fauna replicate surveys of stream fauna was required to be carried out on a monthly basis only during wet season. Three replicates for invertebrates sampling and direct counting of fish fauna should be performed respectively.

Monitoring Location

9.23     During wet season, the monitoring locations required to be carried out in Ma Tso Lung Stream are as follow:

             MS_01

             MS_02

             MS_03

             MS_04

             MS_05

             MS_06

             MS_07

             MS_08

             MS_09

             MS_10

             MS_11

             MS_12

             MS_13

             MS_14

             MS_15

9.24     The location of monitoring stations is shown in Figure 10 for reference.

Monitoring Parameters

9.25     The monitoring parameters and survey methodology for each monitoring station are described below:

       Species composition

       Abundance

       Distribution for invertebrates and fish fauna

       Species of conservation significance would be specified

9.26     Other information at the time of survey such as weather conditions and noticeable natural or anthropogenic activities were recorded.

Monitoring Status

 

9.27     According to the Updated EM&A Manual, quantitative aquatic fauna replicate surveys of stream fauna is required to be carried out on monthly basis during wet season. During the reporting Month, no aquatic fauna replicate surveys was carried out.

 

Monitoring of Measures to Minimise Impacts on Ecological Sensitive Habitats from Disturbance and Pollution

Monitoring Requirements and Protocol

9.28     As required under Section 12.3.2.17 of the Updated EM&A Manual, monitoring of measures to minimise impacts should be carried out during the construction phase.

9.29     The purpose of survey is to monitor the effectiveness of measures to minimise impacts on ecologically sensitive habitats from disturbance and pollution by standard faunal transect surveys.

Mammal survey

9.30     Mammal survey should be performed during both day and night times, in areas along the transect routes which may potentially be utilized by terrestrial mammals. Field signs such as droppings, footprints, diggings and burrows left by larger terrestrial mammals should be observed. Mammals directly observed should be recorded, and identification should be made as accurate as possible form the field signs observed.

9.31     Bat survey should be conducted along the transect routes shortly after sunset, with the use of a bat detector to record the echolocation calls. The relative abundance of the species encountered should be estimated with reference to the baseline monitoring results, i.e. using a scale from one (species recorded within transect routes) to three (dominant species within transect routes), for comparison between baseline results and the current monitoring results. Nomenclature of mammal should be based on Shek (2006).

Herpetofauna survey (Amphibians and Reptiles)

9.32     Both day-time and night-time amphibian surveys should be conducted whenever possible following or during periods of rainfall, focusing on areas suitable for amphibians (e.g. forest, shrublands, grasslands, streams, ponds, marshes, etc.). Calling amphibians should be recorded, supplemented by visual observation of eggs, tadpoles, adult frogs, and toads.

9.33     Active searching of appropriate microhabitats such as stones, pond bunds, crevices and leaf debris should be performed mainly. Observation of exposed, basking and foraging reptiles should also be conducted. Nomenclature of amphibian and reptile should be based on Chan et al. (2005) and Karsen et al. (1998), respectively.

Insect survey (Butterfly and Dragonfly)

9.34     Butterflies and dragonflies observed along the transects should be identified and counted. Preferable habitats of the insects such as watercourses, fishponds, and vegetated areas should be observed with special attention. Nomenclature and protection status of the species should be based on Lo et al. (2005) for butterflies and Tam et al. (2011) for dragonflies.

Monitoring Frequency

9.35     Monitoring surveys of ecological sensitive receivers such as mammals, insects (butterflies and dragonflies), and herpetofauna was undertaken on a monthly bases.

Date of monitoring surveys of ecological sensitive receivers:

5, 12 December 2023

 

Monitoring Location

9.36     The transect routes in the reporting month according to the construction works are as follows:

           T1. Ma Tso Lung riparian zone and associated wetland habitats;

           T1. Green belt areas E1-8, D1-8 and G1-3 in KTN NDA;

           T1. AGR one C2-4 and C2-2 in KTN NDA;

           T1. Area north of Ng Tung River;

           T3. Area west of Siu Hang San Tsuen Stream;

           T4. South side of Fanling Highway and Castle Peak Road in the vicinity of Pak Shek Au;

           T5. Area west and east of the southern limit of the FLN NDA work area; and

           T6. Areas in the western part of KTN.

 

9.37     The location of Transects is shown in Figure 11 for reference.

Monitoring Parameters

9.38     The monitoring parameters and survey methodology for each transect are described below:-

       Species composition

       Abundance

       Distribution for fauna observed

       Species of conservation significance would be specified

Monitoring Results

 

Mammal

9.39     During the survey, a total of 5 mammal species were recorded from transects. Two (2) species of conservation importance were recorded, namely Callosciurus erythraeus and Pipistrellus abramus.

9.40     Domestic dogs, Canis lupus familiaris, were commonly found at transect T3, T4, T5 and T6, where associated with human settlements, whilst domestic cats, Felis catus, was found at T1.

9.41     Echolocation calls of bats were recorded with a bat detector. The bat detector would list out possible bat species having similar echolocation calls in pattern and frequency. The structure of the echolocation calls from the recordings was later analysed to identify species as far as possible (the lack of literature on echolocation call structure makes the field identification of some bat species in Hong Kong difficult, and some species could only be identified to genus level, or remain unidentified from the recordings).

9.42     Identification of bat species encountered in the surveys was made with consideration of the possible bat species suggested by the bat detector, the distribution of suggested bat species in Hong Kong, previous records of bat species in the EIA Report and Baseline Monitoring Report, and the structure of echolocation calls of the recordings (including call structure, frequency, duration, inter pulse interval etc., with reference to relevant literatures).

9.43     Pipistrellus abramus was recorded with FM/QCF call structure and frequency around 45 kHz to 68 kHz (Ma et al., 2010, p.319). The above characteristics were further compared with data from relevant literatures to confirm the identities. References were also made to Tong (2016).

9.44     Bat species, Pipistrellus abramus were recorded in flight at nighttime at transect T1, T4, T5 and T6.

Herpetofauna (Amphibians and Reptiles)

9.45     Among the transects, a total of 9 herpetofauna species were observed. Species including toads, frogs, skinks and geckos were recorded near wetland habitats and watercourse. Transects T5 had the highest species diversity among all transects.

Insects (Butterfly and Dragonfly)

9.46     During the insect survey, a total of 58 butterfly species were recorded from transects. Eight (8) species of butterfly recorded was of particular conservation interest, namely Catochrysops Strabo, Charaxes marmax, Hasora badra, Horaga onyx, Jamides alecto, Jamides celeno, Pieris rapae, and Zizula hylax. Transect T5 had recorded the highest butterfly diversity among all transects.

9.47     10 species of odonata were recorded in the reporting month. Transect T1 had recorded the highest odonatan diversity among all transect.

9.48     Ecological sensitive receivers such as mammals, insects (butterflies and dragonflies), and herpetofauna monitoring during construction phase was conducted in the reporting month and the results are attached in Appendices L2 to L5.

9.49     Table 9.4 summarises the mammal monitoring results during the reporting month.

 

Table 9.4     Summary Table of Mammal Monitoring Results to Corresponding Action and Limit Levels.

Number of Native Species Recorded in each transect

Result in Reporting Month

Baseline Level in Corresponding Month

Action Level

Limit Level

T1

1

1

NA

NA

T3

0

1

NA

NA

T4

1

1

NA

NA

T5

2

1

NA

NA

T6

1

1

NA

NA

9.50     Table 9.5 summarises the herpetofauna monitoring results during the reporting month.

 

Table 9.5     Summary Table of Herpetofauna Monitoring Results to Corresponding Action and Limit Levels.

Number of Native Species Recorded in each transect

Result in Reporting Month

Baseline Level in Corresponding Month

Action Level

Limit Level

T1

4

4

3

2

T3

1

1

NA

NA

T4

0

1

NA

NA

T5

6

3

2

1

T6

0

3

2

1

9.51     Table 9.6 summarises the butterfly monitoring results during the reporting month.

 

Table 9.6     Summary Table of Butterfly Monitoring Results to Corresponding Action and Limit Levels.

Number of Species Recorded in each transect

Result in Reporting Month

Baseline Level in Corresponding Month

Action Level

Limit Level

T1

26

5

4

3

T3

17

1

NA

NA

T4

24

2

NA

1

T5

35

2

NA

1

T6

16

4

3

2

 

 

 

 

9.52     Table 9.7 summarises the odonata monitoring results during the reporting month.

Table 9.7     Summary Table of Odonata Monitoring Results to Corresponding Action and Limit Levels.

Number of Native Species Recorded in each transect

Result in Reporting Month

Baseline Level in Corresponding Month

Action Level

Limit Level

T1

6

4

3

2

T3

1

4

3

2

T4

2

1

NA

NA

T5

5

4

3

2

T6

2

3

2

1

 

9.53     Two (2) Action Level exceedances and two (2) Limit Level exceedance was recorded in non-aquatic fauna monitoring during the reporting month.

9.54     For the monitoring conducted on 12 December 2023 at Transect T5, a section of the transect route was found located within a private property and hence not accessible. The inaccessible part are shown in Photo 1 below. The adjusted accessible transect route is shown in Figure 11.

Photo 1. Inaccessible part of transect T5 located within a private property.

 


 

Results and Observation

Action and Limit Level Exceedance

9.55     Two (2) action level exceedance and two (2) limit level exceedance for non-aquatic fauna were recorded at T3 and T6. The exceedances were considered non-project related.

9.56     Large proportion of vegetative habitat along T3 (including some shrubs, wood and tall grass) were observed either removed, tarmacked, and concreted as haul road by construction works outside of project, first reported in the Monthly Monitoring Report in December 2021. The altered condition at transect might have been less favourable to inhabitance of odonates, as some species of these taxonomic groups prefers wet vegetated habitats that provides shelters, as opposed to open and dry habitat such as a tarmacked haul road. Previous odonate monitoring results see a drop in odonate records between summer of 2021 and 2022, during the period which construction activities outside of project were observed.

9.57     Herpetofauna surveys at T6 were mainly conducted by actively searching appropriate microhabitats such as stones, pond bunds, crevices, and leaf litter/debris. Besides the active searching, observations and noting down of exposed, basking, and foraging herpetofauna were conducted. The result of herpetofauna monitoring at T6 in reporting month also aligned with results in the previous year within the monitoring period, suggesting that environmental factors taking place. Monitoring result will be continuously reviewed for ongoing assessment.

9.58     For the transect of T3 & T6, necessary Ecological mitigation measures were provided by all nearby project-related sites. In addition, no exceedance in other environmental parameters was recorded around 5th &12th December, suggesting that it is unlikely that the exceedance recorded during ecological monitoring in T3 & T6 was project-related. No evidence to suggest that the exceedance was related to project activities, as supported by environmental monitoring data. Future results of these transects will be continuously reviewed.

Details of the Influencing Factors

Major Activities

9.59     During the survey of Monitoring of Measures to Minimise Disturbance to Water Birds in Sheung Yue River and Long Valley, anthropogenic activities including soil turning with excavator and other construction activities were observed in Long Valley. Construction works were observed beside Sheung Yue River.

9.60     The anthropogenic activities affected only a small area of the habitat in Long Valley during monitoring and would only pose minor disturbances to the birds..

9.61     During the survey of Monitoring of Measures to Minimise Disturbance to Water Birds in Ng Tung River, anthropogenic activities including construction works beside T2, recreational usage of remote control boats and helicopters at both T1 and T2, and recreational fishing by fishing rod at both T1 and T2 were observed.

9.62     During the survey of Monitoring of Measures to Minimise Impacts on Ecological Sensitive Habitats from Disturbance and Pollution, construction activities NOT under this Project were observed at T3 and T5.

Weather Conditions

9.63     According to the observation during survey, temperature and the rain flow records in the reporting month (Reference: http://www.weather.gov.hk/wxinfo/pastwx/metob202312.htm), weather conditions might pose influence towards the monitoring results.

9.64     The detailed ecological monitoring results are attached in Appendix L.

References

Ma, J., Jones, G., Zhu, G. J., & Metzner, W. (2010). Echolocation behaviours of the Japanese pipistrelle bat Pipistrellus abramus during foraging flight. Acta Theriologica, 55(4), 315-332.

Tong, C. F. (2016). Distribution and preference of landscape features and foraging sites of insectivorous bats in Hong Kong urban parks. (Master dissertation)