5.
ECOLOGY
MONITORING
5.1
Ardeid Night Roost Monitoring
5.1.1
Monitoring Requirement
With reference to the Pre-construction Ardeid Night
Roost survey (January 2021) findings that identified two active ardeid night
roosts within 100 m from the Project boundary (one approximately 40 m east of
the Project boundary and the other one approximately 45 m northeast of the
Project boundary), consequent monthly monitoring of these active ardeid night
roosts was done in accordance to the EM&A Manual Sections 7.3.10 and 7.3.11; and EIA Report Section 8.12.1.3.
The survey was conducted
with the following objectives:
·
Check the status and
location of any active ardeid night roosts within 100 m from the Project
boundary with reference to EM&A Manual Section 7.3.10;
·
Monitor the effectiveness
of proposed mitigation measures and detect any unpredicted indirect ecological
impacts arising from the proposed Project as specified in EIA Report Section
8.12.1.3; and
·
Recommend remedial actions,
where appropriate, based on the impact monitoring results (EIA Report Section
8.12.1.3) for the implementation of
the contractor as only necessary.
5.1.2
Monitoring Methodology
5.1.2.1
Monitoring
Area
With reference from Section 7.3.10 of the
approved EM&A Manual, the monitoring was
conducted in areas within 100 m from the Project boundary. The monitoring area
and vantage points for direct observation of any active night roosts are shown
in Appendix O.
5.1.2.2
Monitoring
Activity
5.1.2.2.1 Active Ardeid Night Roost
Current Survey focused on the two active night
roosts within the Survey Area that were previously confirmed during the
pre-construction Survey. These roosts include one that was approximately 40 m
east of the Project boundary and another one around 45 m northeast of the
mentioned boundary (Section 3 of the approved Pre-construction Survey Report of Ardeid Night
Roost). Primary data collection
with the use of 7x and 10x binoculars; and field guides including the Avifauna
of Hong Kong (Carey et al., 2001) and The Birds of Hong Kong and South China (Viney et al., 2005), was from about one hour before sunset
time until one hour after sunset with reference to Section 7.3.10 of the
approved EM&A Manual. Sunset time was according
to Hong Kong Observatory (HKO). The survey was conducted on 19 October 2021.
Species composition, abundance and locations of
night roosts were recorded. Species composition, abundance and location of
pre-roosting aggregations (PRA) were also noted. PRAs are gatherings of avian
individuals prior to flying into a night roost (Moore and Switzer, 1998). The
time of return of the ardeids to the pre-roost and the final night roost were
also recorded. Direct observations were made from vantage points adjacent the
Project site with clear and unobstructed view of any active roosting location
(s) within the Survey Area. However, aside from the established vantage points
for the focused mangrove strips along Shan Pui River,
observations were also conducted throughout the whole 100 m study site to cover
other areas aside from the mangrove strips.
Observations such any changes in site condition or
disturbances detected or observed at the monitoring locations, including both
construction and non-construction related activities, during the monitoring
activity was recorded with reference to Section 7.3.10 of the
approved EM&A Manual. Additionally, other
observations such as bird droppings on the ground which may possibly indicate
presence of night roosts were noted in addition to noting of the roosting
substrate (i.e. substrate species and approximate height). Any breeding
activity usage of the roosting locations within the Survey Area was also noted.
5.1.2.2.2 Noise Monitoring
Monitoring Locations, Frequency, Time and Parameters
The noise monitoring locations were established at
22°28’4.25”N, 114°1’41.32”E; and 22°28’10.43”N,
114°1’42.17”E for NMS1 and NMS2 stations, respectively. Monitoring frequency was
only once a month in concurrence with the construction phase monthly monitoring
of the active night roosts for correlation. Monitoring time for both stations
started around 18:03, the earliest final night roost period recorded during the
survey, and lasted for 30 minutes. Table 5.1
presents the monitoring parameters.
The Action and
Limit Levels for Active Ardeid Night Roost Survey have been set and are presented in Appendix C.
However,
exceedances to the limit level were endeavoured to be prevented by the full
implementation of mitigation measures (Section 4.2 of the approved
Pre-construction Survey Report of Ardeid Night Roost and Sections
5.2.1-5.2.2 of this Report) during the construction phase.
Event and Action Plan
In instances of exceedance/s in the action and/or
limit levels, the different measures as specified in Table 3.3 Event and Action
Plan for Construction Noise of the approved EM&A
Manual and likewise presented in Appendix
H of this report shall be
implemented as responses.
5.1.3
Monitoring Results
5.1.3.1
Active
Ardeid Night Roost
The monitoring activity was conducted on 19 October
2021 and started around 16:55 (one hour before sunset) on a low tide condition.
During the pre-roost period (PRP), the period when avian individuals (ind.)
gather first before flying into a night roost, individuals of Chinese Pond
Heron Ardeola bacchus (3
ind.), Great Egret Ardea alba (5 ind.) and Little Egret Egretta garzetta (7
ind.) were observed in pre-roost aggregate (PRA) around 16:55 on the exposed
mudflat east side (ANR1) of the Project boundary. Additionally, individuals of
similar species Chinese Pond Heron (5 ind.), Great Egret (9 ind.) and Little
Egret (15 ind.) were also noted on the exposed mudflat northeast (ANR2) of the
Project boundary during the period (Table 5.2). For the final
night roost at around 18:03, Chinese Pond Heron individuals were observed at both
the roosting areas ANR1 (14 ind.) and ANR2 (6 ind.). No disturbances
(construction related and/or otherwise) to the active night roost areas was
observed during the period. Bird droppings were observed within the vicinity of
the roosting area located east of the Project boundary.
5.1.3.2
Noise
Monitoring
Noise monitoring activities were conducted on 19
October 2021 in concurrence with the construction phase monthly monitoring of
the pre-identified active night roosts. Noise monitoring started at 18:03 and
lasted for 30 minutes, until 18:33.
Current survey results showed noise levels (LAeq (30 min.)) at both monitoring stations to
be well below the action and limit levels as presented in Table 5.3.
5.1.4
Detection of Any Unpredicted Indirect Ecological
Impacts Arising from the Project
No unpredicted indirect
ecological impacts that arose from the project was noted during the current
monitoring period.
5.1.5
Summary
5.1.5.1
Status
and Location of Any Active Ardeid Night Roost
Two active ardeid night roost areas (ANR1 and ANR2)
were observed within the Survey Area during the October 2021 monitoring period.
These roosts were located at the mangrove strips in the east and northeast
portions of the Project boundary. These were used by individuals of Chinese
Pond Heron.
5.1.5.2
Noise
Monitoring Results
Both noise levels at each of the monitoring
stations were below the action and limit levels.
5.2
Ecological Monitoring of Birds
5.2.1
Monitoring Requirement
With reference to Section 7.3.6 of the EM&A Manual, monthly ecological monitoring of birds, focusing on avifauna species of
conservation interest, and overwintering waterbirds utilising wetland habitats
in Fung Lok Wai and Nam Sang Wai as well as along Shan Pui
River and Kam Tin River within the monitoring area (500 m from the Project
Boundary) in addition to monitoring on the utilization of wetland habitats by
birds also within the same monitoring area as required by Section 7.3.1 of the EM&A Manual.
5.2.2
Monitoring Methodology
5.2.2.1
Monitoring
Area
The monitoring area include wetland habitats in
Fung Lok Wai and Nam Sang Wai as well as along Shan Pui
River and Kam Tin River within 500m from the Project boundary with reference to
Section 7.3.6 of the EM&A Manual. The location of point
count sites and transect routes is shown in Appendix P.
5.2.2.2
Monitoring
Activity
Avifauna survey on the different wetland habitats
using the transect count and point count methods was conducted on 15 October
2021 (day time survey) which started around 07:30. Meanwhile, the survey
overlooking the mudflats and mangroves in the Shan Pui
River was concurrently conducted on the same date with the day time survey
during the low tide (generally 1.5m or below) period at around 11:15. The
methodology for the monitoring activity followed Sections 8.3.3.6 and 8.3.3.7 of the EIA Report (AEIAR-220/2019) and as
detailed below.
For the transect count and point count methods, the
presence and relative abundance of avifauna species at various wetland habitats
were recorded visually and aurally.
Avifauna species were detected either by direct
sighting or by their call and identified to species level. Any notable
behaviours such as feeding, roosting and breeding were also recorded. Bird
species encountered outside the point count locations and walk transects were
also recorded. A comprehensive list of species recorded from the Assessment
Area was prepared, with wetland-dependence, conservation and/or protection
status indicated. Ornithological nomenclature in this report follows Carey et
al. (2001), Viney et al. (2005) and the most recent
updated list from Hong Kong Bird Watching Society (HKBWS).
Noise levels were recorded with the methodology and equipment as
mentioned in Section 3.4 and Section 3.2, respectively, of this EM&A report. The parameter as shown in was
recorded at each of the point count locations.
In addition to recording of noise levels, any changes in site condition
or disturbances detected or observed at the monitoring locations, including
both construction and non-construction related activities with reference to Section 7.3.7 of the EM&A Manual were
also noted.
5.2.2.3
Data
Analysis
For the bird
communities, the monitoring results were compared to pre-construction baseline condition
during the dry and wet seasons as summarized in the Baseline Bird Survey Report
with reference to Section 7.3.8 of the EM&A Manual. However, to
further account the seasonality, monitoring results of the current month was
compared to the results of the corresponding month of the baseline data.
The data for point count method and transect walk
method were presented separately to account for the difference in the survey
effort of the two methods. For each method, abundance and species composition
of the avifauna communities during the monitoring month were summarized.
To check the presence of variation in bird
abundance between baseline and impact monitoring, t-test was applied (α =
0.05). Moreover, to check the presence of variation in bird species diversity,
the two-sided Hutcheson t-test was also used. The two-sided Hutcheson t-test was
developed as a method to compare the diversity of two community samples using
the Shannon diversity index (Hutcheson 1970). Shannon diversity index will be
computed using the formula,
where, H’ = Shannon
Diversity Index; Pi = proportion of the population of species; i; number of species in sample; ln = natural logarithm. Shannon
diversity index is used as it accounts the proportion (relative abundance) of
each species; thus, it gives a better description of diversity than a plain
number of species (species richness).
The Action and
Limit Levels for ecological monitoring of birds have been set and are presented
in Appendix C.
Wetland habitat
utilization during the construction phase monitoring shall only be compared
seasonally, hence the comparison shall only be done after all the data (dry
season and wet season) were collected with reference to Appendix 8.5 of the approved EIA Report.
5.2.3
Monitoring Results
Results of the avifauna survey on the different
habitats within the monitoring area using the transect count and point count
methods as conducted last 15 October 2021 (day time
survey) are presented in Sections 5.2.3.1 and 5.2.3.2. Meanwhile, results for the surveys overlooking the mudflats and
mangroves in the Shan Pui River, with monitoring
activities conducted on similar date with the day time
survey during the low tide (generally 1.5m or below) period which started around
11:15 had results presented in Section 5.2.3.3.
5.2.3.1
Abundance
5.2.3.1.1 All Avifauna Species
An overall total of 472 avifauna ind. was recorded
in the monitoring area during the October 2021 monitoring period, of which 205
ind. were recorded from the point count method and 267 ind. from the transect
walk method. Relative to the October 2016 baseline data (point count method =
157; and transect walk = 51), increases in total abundances in both methods
were observed during the current period. These findings are summarized in Table 5.5.
5.2.3.1.2 Avifauna Species of Conservation
Importance
Of the 472 avifauna individuals recorded in the
monitoring area during the October 2021 monitoring period, 235 ind. (point
count method = 73 ind.; transect walk method = 162 ind.) were of conservation
importance. With reference to October 2016 data, current results showed an
insignificant decrease in total abundance of point count method (t-value =
-0.55; p-value = 0.58; α = 0.05) while an increase transect walk method
was noted. These findings are summarized in Table 5.6.
5.2.3.2
Diversity
(Species Richness[1] and
Shannon Diversity Index[2])
5.2.3.2.1 All Avifauna
Species
A total of 37 avifauna species (species richness)
was recorded during the October 2021 monitoring period, of which, 31 spp. were
recorded by the point count method while 27 spp. were noted by the transect
walk method. Relative to the baseline data (point count method = 32 spp.;
transect walk method = 13 spp.), decrease in total species richness by one
species for the point count method was noted. In terms of Shannon
diversity index (H’), increases from baseline reference values were observed
both in point count method and transect walk method.
Details of these findings are summarized in Table 5.7.
5.2.3.2.2 Avifauna Species of
Conservation Importance
Of the 37 species of avifauna identified during the
October 2021 monitoring period, 11 species of conservation importance were
identified from the point count method, while nine species from the transect
walk method. Relative to the baseline values in October 2016, decrease in the
number of species with conservation importance was recorded from the point
count method while an increase in transect walk method was noted. In terms of
H’, no significant decline (t-value = 0.39; t-crit = 1.97; p-value =0.70;
α = 0.05) was observed from the point count
method, from H’ = 2.17 in October 2016 to H’=2.12 of the current period while
an increase in the current H’ was noted from the transect walk method with
respect to the baseline value of H’= 0.75. Details of these findings are
summarized in Table 5.8 and Appendix F.8.
5.2.3.3
Wetland
Habitat Utilization
Avifauna communities were observed during the
current monitoring period in the different wetland habitats, i.e. modified
watercourse, ponds and mangrove.
With reference to Section 7.3.1 of the EM&A Manual, the utilization of the wetland habitats by birds within the monitoring
area was recorded and monitored.
5.2.3.3.1 All Avifauna
Species
During the current monitoring period, majority of
the wetland habitats were less utilized by avifauna communities as evident with
the very low (VL) abundances in these areas. However, among these habitats, low
to medium (L-M) abundance was noted at the Active Ponds North to Nullah 2 in
Fung Lok Wai. With regards to species richness, while some of the habitats were
noted with none, very low or very low to low values, both the Active Ponds
adjacent to Project site in Fung Lok Wai and Active Ponds North to Nullah 2 in
Fung Lok Wai were observed with moderate to high (M-H) species richness during
the period (Table 5.9).
5.2.3.3.2 Avifauna Species of
Conservation Importance
Wetland habitats were noted with none to very low
(VL) abundances of species with conservation importance during the current
monitoring period which then indicated a generally very low utilization of
these areas. In terms of species richness, majority of the wetland habitats
were also utilized by very low number (VL) of species (Table 5.10).
5.2.3.3.3 Overwintering Avifauna Species
Three winter visitor species including the Grey
Heron Ardea cinerea,
Great Cormorant Phalacrocorax cardo and Pied Avocet Recurvirostra avosetta were
observed utilizing the wetland habitats within the survey area during this
monitoring period. Still very low (VL) abundances and species richness of
overwintering avifauna species were observed in the different wetland habitats
(Table 5.11) which could imply the start of their migration to the area relative to
the coming dry season.
5.2.3.4
Noise
Levels
Noise levels LAeq
(30 min) recorded on 15 October 2021 (daytime) from each of the point count
locations during the ecological bird monitoring are shown in Table 5.12.