5.1.3.2
Noise Monitoring
Noise
monitoring activities were conducted on 11 June 2021 in concurrence with the
construction phase monthly monitoring of the pre-identified active night
roosts. Noise monitoring started at 18:50 and lasted for 30 minutes, until
19:20.
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
One
active ardeid night roost site (ANR1) was observed within the Survey Area
during the June 2021 monitoring period. This roost was located at the mangrove
strip in the east portion of the Project boundary. This was used by individuals
of Little Egret. The other night roost site (ANR2) was not used during the
period.
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 June 2021 (daytime survey) which started
around 06:50; and on 18 June 2021 (night time survey) around 19:09 while the
survey overlooking the mudflats and mangroves in the Shan Pui River was
conducted on 15 June 2021 during the low tide (generally 1.5m or below) period
which also started around 06:50. 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 June 2021
(daytime survey) which started around 06:50; and on 18 June 2021 (night time
survey) are presented in Sections 5.2.3.1 and 5.2.3.2 while results for the
surveys overlooking the mudflats and mangroves in the Shan Pui River, with
monitoring activities conducted on 15 June 2021 during the low tide (generally
1.5m or below) period which also started around 06:50 had results presented in
Section 5.2.3.3.
5.2.3.1
Abundance
5.2.3.1.1 All
Avifauna Species
A
total 332 avifauna ind. was recorded in the monitoring area during the June
2021 monitoring period, of which 189 ind. were recorded from the point count
method and 143 ind. from the transect walk method. Relative to the June 2017
baseline data, increase in total abundance was observed. In June 2017, a total
of 190 ind. were recorded, of which 121 ind. were from point count method and
69 ind. from transect walk method. These findings are summarized in Table 5.5.
5.2.3.1.2 Avifauna
Species of Conservation Importance
Of
the 332 avifauna individuals recorded in the monitoring area during the June
2021 monitoring period, 163 ind. were of conservation importance. A total of
108 ind. were recorded from point count method and 55 ind. were from transect
walk method. Relative to the June 2017 baseline data, increase in the abundance
of avifauna species of conservation importance was observed. In June 2017, a
total of 85 ind. were recorded, of which 45 ind. were from point count method
and 40 ind. were from transect walk method. The high abundances of Chinese Pond
Heron Ardeola bacchus during the
current monitoring period contributed to the increase in counts of avifauna species
of conservation importance. 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 21 avifauna species (species richness) was recorded during the June
2021 monitoring period, of which 18 species were identified using point count
method and also 18 species using transect walk method. Relative to the June
2017 baseline data, a decrease in the total species richness from 28 species in
June 2017 to 21 species in the current monitoring period was noted. In terms of Shannon diversity index
(H’), a significant decline (t-value = 7.16; t-crit = 1.97; p-value = 5.99E-12;
α = 0.05) from baseline reference values was observed in point count method,
from H’=3.93 in June 2017 to H’=2.99 in June 2021. However, the significant
decline may not be attributed to the construction works of the Project as noise
levels [47.5 dB(A) to 65.9 dB(A)] concurrently recorded from the different
point count locations during the current ecological bird monitoring are
generally low. On the other hand, transect walk method showed an increase in H’
from the baseline value of H’=2.09 to H’=2.71 during the current monitoring
period. Details of these findings are summarized in Table 5.7 and are further discussed
in Appendix F.1.2.
5.2.3.2.2
Avifauna Species of Conservation Importance
Of
the 21 species of avifauna identified during the June 2021 monitoring period,
four species of conservation importance were identified from the point count
method and also four species from the transect walk method. Relative to the
baseline values in June 2017, the species of conservation importance recorded
from the point count method decreased by one and increase by one species from
the transect walk method. In terms of H’, a significant decline ((t-value =
5.50; t-crit = 1.98; p-value =1.77E-07; α = 0.05) was observed from the point
count method, from H’ = 2.69 in June 2017 to H’=1.69. However, as
aforementioned, the significant decline was observed to be due to other factors
and not project-related. i.e. dominance of Chinese Pond Heron. On the other
hand, transect walk method showed an increase in overall H’ from H’ = 1.04 in
June 2017 to H’=1.14 in June 2021. Details of these findings are summarized in
Table 5.8 and are further discussed in Appendix F.1.2.
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, mangrove, 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 as evident with the very low to low (VL; and
VL-L) abundances in these areas. With regards to species richness, generally
very low (VL) number of species was noted in the different wetland habitats
except in the Active Ponds North to Nullah 2 (L-M, low to moderate) in Fung Lok
Wai (Table
5.9).
5.2.3.3.2
Avifauna Species of Conservation Importance
All
of the wetland habitats were noted with very low abundances (VL) of species
with conservation importance during the current monitoring period which then
indicated subsequent very low utilization of these areas. In terms of species
richness, all 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
Several
species including the Black-crowned Night Heron Nycticorax nycticorax, Black Kite Milvus migrans, and Great Egret which are both winter visitors and
residents in Hong Kong in addition to White Wagtail Motacilla alba a winter visitor and passage migrant, were observed
during this monitoring period. However, as the current monitoring period
covered the summer season, it was likely that these individuals were either
residents or passage migrant. Hence, no overwintering species that utilized the
different wetland habitats was recorded during the period.
5.2.3.4
Noise Levels
Noise
levels LAeq (30 min) recorded on 15 June 2021 (daytime) and 18 June
2021 (night time) from each of the point count locations during the ecological
bird monitoring are shown in Table
5.11.