5.1.3.2
Noise
Monitoring
Noise monitoring activities were conducted on 16
December 2021 in concurrence with the construction phase monthly monitoring of
the pre-identified active night roosts. Noise monitoring started at 17:35 and
lasted for 30 minutes, until 18:05.
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 December 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, Great Egret 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
Night time avifauna survey on the different wetland
habitats using the transect count and point count methods was conducted on 16
December 2021 which started around 17:42; meanwhile, the day time survey was
conducted on 22 December 2021 which started around 07:30. For the survey
overlooking the mudflats and mangroves in the Shan Pui
River, it was concurrently conducted on the same date with the day time survey
during the low tide (generally 1.5m or below) period at around 07:30. 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 16 December 2021 (night time
survey) and 22 December 2021 (daytime 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 daytime survey during the low
tide (generally 1.5m or below) period which started around 07:30 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 580 avifauna individuals was recorded in the monitoring area during the December
2021 monitoring period, of which 428 individuals were recorded from the point count method and 152 individuals from the transect walk method. Relative to the December
2016 baseline data (point count method = 530; and transect walk = 85), a
current insignificant decrease in total abundance for the point count method
(t-value = 0.76; p-value =0.45; α = 0.05) and an increase in the transect
walk method results were noted. Details of these findings are summarized in Table 5.5 and Appendix F.7.
5.2.3.1.2 Avifauna Species of Conservation Importance
Of the 580 avifauna individuals recorded in the
monitoring area during the December 2021 monitoring period, 430 individuals (point count method = 329 individuals; transect walk method = 101 individuals) were of conservation importance. With reference
to December 2016 data, current results showed an insignificant decrease in
total abundance of point count method (t-value = 1.23; p-value = 0.22; α =
0.05) while an increase in transect walk method was noted. Details of these
findings are summarized in Table 5.6 and Appendix F.7.
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 December 2021 monitoring period, of which, 31 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 = 35 species;
transect walk method = 22 species), decreases in total species richness for
both the point count method and transect walk method were noted. In terms of Shannon
diversity index (H’), an increase from baseline reference values was observed
in point count method while an insignificant decrease of H’ in transect walk method (t-value = 0.26; t-crit = 1.97; p-value =0.79; α = 0.05) was noted. Details of these findings are summarized in Table 5.7 and Appendix F.8.
5.2.3.2.2 Avifauna Species of
Conservation Importance
Of the 35 species of avifauna identified during the
December 2021 monitoring period, 17 species were of conservation importance (point
count method = 16 species; transect walk method = 11 species). Relative to the
baseline values in December 2016, decrease in the number of species with
conservation importance was recorded from the point count method while an
increase in the number of species with conservation importance for the transect
walk method was noted. In terms of H’, increases were currently observed.
Increase in the point count method, from H’ = 2.04 in December 2016 to H’=2.26
of the current period; as well as increase in the transect walk method, from H’
= 1.39 in December 2016 to H’=2.07 of the current period were noted. 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, majority of
the wetland habitats were less utilized by avifauna communities in terms of
their abundances (very low to low) although the area at Upper course of Shan Pui River along Yuen Long Industrial Estate (YLIE) was noted
with low to moderate number of avifauna individuals. In terms of species
richness, particularly medium to high number of species were present in Upper
course of Shan Pui River along YLIE during the period
(Table 5.9).
5.2.3.3.2 Avifauna Species of
Conservation Importance
Majority of the wetland habitats were less utilized
by avifauna communities in terms of their abundances (very low to low) although
one habitat, the Upper course of Shan Pui River along
YLIE, was observed with low to moderate abundance (L-M). In terms of species
richness, majority of the wetland habitats were also consequently utilized by
very low number (VL) of species (Table 5.10).
5.2.3.3.3 Overwintering Avifauna Species
A total of 16 winter visitor species were observed
utilizing the wetland habitats within the survey area during this monitoring
period. Majority of these wetland habitats were noted with very low (VL)
abundances and species richness of overwintering avifauna species (Table 5.11).
5.2.3.4
Noise
Levels
Noise levels LAeq
(30 min) recorded on 16 December 2021 (night time) and 22 December 2021 (day
time) from each of the point count locations during the ecological bird
monitoring are shown in Table 5.12.