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 Ardeid Night Roost
Monitoring 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 (Survey Area) 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 Ardeid Night Roost Monitoring Survey
focused on the two active night roosts within the Survey Area (100 m from the
Project boundary) 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 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 17 June 2022.
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 as 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 19:21, 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 17 June 2022 and started around 18:09 (one hour
before sunset) on a low tide condition. During the pre-roost period (PRP), the
period when avian individuals gather first before flying into a night roost,
two Little Egret Egretta garzetta
individuals were observed in pre-roost aggregate (PRA) around 19:05 at the
mudflat east side (ANR1) of the Project boundary while another two Little Egret
individuals were also concurrently noted at the mudflat northeast side (ANR2) of
the Project boundary during the period (Table 5.2).
For the final
night roost at around 19:21, Chinese Pond Heron (1 individual) and Little Egret
(1 individual) were observed at the roosting area ANR1 utilizing the understory
layer of the roosting substrate Sonneratia apetala and S. caseolaris; concurrently, similar two species (Chinese
Pond Heron with 3 individuals; and Little Egret with 2 individuals) were also
noted at ANR2 that utilized the canopy layer of the aforementioned roosting
substrate.
No disturbance
(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 17 June
2022 in concurrence with the construction phase monthly monitoring of the pre-identified
active night roosts. Noise monitoring started at 19:21 and lasted for 30
minutes, until 19:51.
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 were 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 June 2022 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, and Little Egret.
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)
was conducted 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 included 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 surveys on the different wetland habitats
using the transect count and point count methods was conducted on 13 June 2022
(daytime) and 17 June 2022 (night-time). The daytime survey started around
07:45 while the night-time survey started at 19:09. For the survey overlooking
the mudflats and mangroves in the Shan Pui River that
was concurrently conducted on the same date with the daytime survey during the
low tide (generally 1.5m or below) period, it started at around 13:05. 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 were
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 13 June 2022 (daytime) which started around 07:45 and
on 17 June 2022 (night-time) which started around 19:09, 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 daytime survey during the low
tide (generally 1.5m or below) period around 13:05 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 202 avifauna individuals was recorded in the monitoring area during the
June 2022 monitoring period, of which 128 individuals were recorded from the point count method and 74 individuals from the transect walk method. Relative to the
June 2017 baseline data (point count method = 121; and transect walk = 69),
current increases in total abundance for both the point count and transect walk
methods were noted. Details of these findings are summarized in Table 5.5.
5.2.3.1.2 Avifauna Species of Conservation Importance
Of the 202 avifauna individuals recorded in the monitoring
area during the June 2022 monitoring period, 92 individuals (point count method = 50 individuals; transect walk method = 42 individuals) were of conservation importance. With reference
to June 2017 data, current results showed increases in total abundance of both
point count and transect walk methods were noted. Details of 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 19 avifauna species (species richness)
were recorded during the June 2022 monitoring period, of which, 18 species were
recorded by the point count method while 11 species were noted by the transect
walk method. Relative to the baseline data (point count method = 25 species;
transect walk method = 13 species), decreases in total species richness for
both the point count and transect walk methods were noted. In terms of Shannon
diversity index (H’), a significant decrease in point count method (t-value = 4.11;
t-crit = 1.97; p-value =0.00; α = 0.05) from
baseline reference value was observed while an insignificant decrease (t-value
= 0.65; t-crit = 1.98; p-value =0.52; α = 0.05)
in the transect walk method was additionally noted. Details of these findings are summarized in Table 5.7 and Appendix F.6.
5.2.3.2.2 Avifauna Species of
Conservation Importance
Of the 19 avifauna species of avifauna identified
during the June 2022 monitoring period, four species were of conservation
importance (point count method = 4 species; transect walk method = 3 species).
Relative to the baseline values in June 2017, decrease in the number of species
with conservation importance was recorded from the point count method while the
number of species with conservation importance from the transect walk method
remain unchanged. In terms of Shannon diversity index (H’), In terms of Shannon
diversity index (H’), a significant decrease in point count method (t-value =
4.36; t-crit = 1.99; p-value =0.00; α = 0.05)
from baseline reference value was observed while an insignificant decrease
(t-value = 1.02; t-crit = 1.99; p-value =0.31; α
= 0.05) in the transect walk method was additionally noted. Details of these findings are summarized in Table 5.8 and Appendix F.6.
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
different wetland habitats were observed with very low (VL) abundance. In terms
of species richness, majority of these wetland habitats were also observed with
very low (VL) number of species (Table 5.9).
5.2.3.3.2 Avifauna Species of
Conservation Importance
All of the different wetland habitats had very low
(VL) abundance of avifauna species with conservation importance and were also
utilized by very low (VL) number of these species (Table 5.10).
5.2.3.4
Noise
Levels
Noise levels LAeq
(30 min) recorded on 13 June 2022 (daytime) and 17 June 2022 (night-time) from
each of the point count locations during the ecological bird monitoring are
shown in Table 5.11.