5.1.3.2
Noise
Monitoring
Noise monitoring activities were conducted on 16
September 2022 in concurrence with the construction phase monthly monitoring of
the pre-identified active night roosts. Noise monitoring started at 18:30 and
lasted for 30 minutes, until 19:00.
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 September 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 were conducted last 15
September 2022 (daytime) which started around 07:45; and 16 September 2022
(night-time) which started around 18:28. 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 07:45. 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 15 September 2022 (daytime) which started around
07:45; and 16 September 2022 which started around 18:28 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 07:45 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 255 avifauna individuals was recorded in the monitoring area during the
September 2022 monitoring period, of which 180 individuals were recorded from the point count method and 75 individuals from the transect walk method. Relative to the
September 2016 baseline data (point count method = 222; and transect walk =
119), current decreases in total abundance for the point count method (t-value
= 1.90; p-value = 0.06; α = 0.05); and transect walk method (t-value =
1.45; p-value = 0.15; α = 0.05) were observed. These decreases are
consistent with the trend observed in the nearby Deep Bay Area, where it was
reported that from 2000 to 2018 there has been a consistent decline in coverage
of intertidal mudflat, consistent increase in coverage of mangrove and other
vegetation (Sung Y-H et. al., 2021).
Additionally, within the monitoring area, the mudflat at the confluence
area of Shan Pui River and Kam Tin River, adjacent to
Project site was progressively invaded most probably by the fast-growing exotic
mangrove species Sonneratia
spp. as also initially reported in the EIA report. The decrease in mudflat
coverage may imply a decrease in foraging area for waterbirds, hence, could
have led the current decreases in abundances.
Details of these findings are summarized in Table 5.5; and Appendices F.6.1 and F.6.2.
5.2.3.1.2 Avifauna Species of Conservation Importance
Of the 255 avifauna individuals recorded in the
monitoring area during the September 2022 monitoring period, 98 individuals (point count method = 77 individuals; transect walk method = 21 individuals) were of conservation importance. With reference
to September 2016 data, current results showed decreases in total abundance for
the point count method (t-value = 1.35; p-value = 0.18; α = 0.05); and in
transect walk method (t-value = 1.36; p-value = 0.19; α = 0.05) results
were noted. Details of these findings are summarized in Table 5.6; and Appendices F.6.3 and F.6.4.
5.2.3.2
Diversity
(Species Richness[1] and
Shannon Diversity Index[2])
5.2.3.2.1 All Avifauna
Species
A total of 35 avifauna species (species richness)
were recorded during the September 2022 monitoring period, of which, 32 species
were recorded by the point count method while 21 species were noted by the
transect walk method. Relative to the baseline data (point count method = 34
species; transect walk method = 27 species), decreases in total species
richness for both the point count and transect walk methods were noted. In terms of Shannon
diversity index (H’) values, current result in point count method showed an
increase from baseline reference value while a decrease (t-value = 1.34; t-crit = 1.97; p-value =0.18; α = 0.05) in transect walk
method was noted. Details of these findings
are summarized in Table 5.7 and Appendix F.7.1.
5.2.3.2.2 Avifauna Species of
Conservation Importance
Of the 35 avifauna species identified during the
September 2022 monitoring period, 12 species were of conservation importance
(point count method = 12 species; transect walk method = 7 species). Relative
to the baseline values in September 2016, the number of species with
conservation importance recorded from the point count method remained the same
while the number of species with conservation importance from the transect walk
method decreased. In terms of Shannon diversity index (H’), increases in
point count and transect walk methods were noted relative to the baseline
reference values. Details of these findings
are summarized in Table 5.8.
5.2.3.3
Wetland
Habitat Utilization
Avifauna communities were observed during the current
monitoring period in the different wetland habitats, i.e. mangrove, modified
watercourse, ponds, and reedbed.
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, all of the different wetland habitats were observed with
very low (VL) abundance. In terms of species richness, majority of these
wetland habitats were observed with very low to low (VL-L) number of species (Table 5.9).
5.2.3.3.2 Avifauna Species of
Conservation Importance
Majority of the different wetland habitats had very
low (VL) abundance of avifauna species of conservation importance; and were
also utilized by a majority of very low (VL) number of these species (Table 5.10).
5.2.3.4
Noise
Levels
Noise levels LAeq
(30 min) recorded on 15 September 2022 (daytime) and 16 September 2022
(night-time) from each of the point count locations during the ecological bird
monitoring are shown in Table 5.11.