5.1.3.2
Noise Monitoring
Noise monitoring
activities were conducted on 18 May 2021 in concurrence with the construction
phase monthly monitoring of the pre-identified active night roosts. Noise
monitoring started at 18:10 and lasted for 30 minutes, until 18:40.
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 was observed within the Survey Area during the May 2021 monitoring
period. This roost was located at the mangrove strip in the east portion of the
Project boundary. This was used by the different ardeid species such as the
Eastern Cattle Egret, Little Egret, Chinese Pond Heron and Great 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) 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 17 May 2021 at suitable time (early morning) which started around
06:50, when birds are most active. For the surveys overlooking the mudflats and
mangroves in the Shan Pui River, monitoring activities were also conducted on
the same date and time (06:50) during the low tide (generally 1.5m or below)
period. 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. No night-time
survey was scheduled during the current monitoring month.
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 17 May 2021 which started
around 06:50 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 the same date 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
A total of 175 avifauna
individuals (ind.) was recorded during the current monitoring period using point
count (101 ind.) and transect walk (74 ind.) methods. A decrease in abundance
was noted in this period relative to the baseline May 2017 results with a total
abundance of 192 ind. (point count=190 ind; transect walk=2 ind.).
5.2.3.1.1
All Avifauna Species
Point Count
A total of 101 avifauna
ind. was observed within the monitoring area using the point count method.
Among the different species recorded, the Spotted Dove Spilopelia chinensis was noted with the highest abundance (17
ind.), followed by the Chinese Pond Heron Ardeola
bacchus (15 ind.) and Red-whiskered Bulbul Pycnonotus jocosus. The high abundance of Spotted Dove could be due
to them being an abundant resident in Hong Kong. On the other hand, several
species were noted with low abundances (only one ind.), these include the
Common Kingfisher Alcedo atthis,
Great Egret Ardea alba and
White-breasted Waterhen Amaurornis
phoenicurus, just to name a few.
Relative to the May 2017 baseline
data (190 ind.), a decline in the current monitoring results was observed.
However, the decline was not statistically significant at α = 0.05 (two-tailed
unpaired t-test for abundance).
Transect Walk
A total of 74 avifauna
ind. was observed within the monitoring area using the transect walk method.
Among the different species recorded, the Barn Swallow Hirundo rustica was noted with the highest abundance (8 ind.),
followed closely by the Chinese Pond Heron (7 ind.); and Azure-winged Magpie Cyanopica cyanus, Eurasian Tree Sparrow Passer montanus and Masked
Laughingthrush Garrulax perspicillatus
with five recorded individuals each.
Increase in the abundance
was noted during the current monitoring period with respect to the baseline
data which only recorded 2 ind.
5.2.3.1.2
Avifauna Species of Conservation Importance
Point Count
A
total of 21 avifauna ind. of conservation importance was observed within the
monitoring area using the point count method. Among the different species
recorded, the Chinese Pond Heron was noted with the highest abundance (15 ind.)
while the remaining species such as the Little Egret Egretta garzetta (2 ind.); followed by the Black Kite Milvus migrans, Collared Crow Corvus torquatus, Great Egret and Little
Grebe Tachybaptus ruficollis (each
with only 1 ind.) were already noted with low abundances.
Current monitoring results
(21 ind.) showed a decrease in abundance relative to the May 2017 baseline data
(71 ind.). The decrease was primarily due to the current lesser abundances of
the Great Egret, Black-winged Stilt Himantopus
himantopus and Little Grebe.
However, the decrease in
abundance was not statistically significant at α = 0.05.
Transect Walk
A
total of 16 avifauna ind. of conservation importance was observed within the
monitoring area using the transect walk method. Among the different species
recorded, the Chinese Pond Heron was noted with the highest abundance (7 ind.).
The remaining species such as the Great Egret (4 ind.), Little Grebe (3 ind.)
and Grey Heron (2 ind.) were noted with low abundances. Relative to the
baseline data (2 ind.), an increase was noted during the current period.
5.2.3.1.3
Summary
Summary of the baseline
and impact monitoring abundance results are shown in Table 5.5 and Table
5.6.
5.2.3.2
Diversity (Species Richness[1]
and Shannon Diversity Index[2])
A total of 31 avifauna
species (species richness) was noted during the current monitoring period in the
different wetland habitats using the point count (22 species) and transect walk
(23 species) methods. With respect to the May 2017 baseline data, similar total
number of species (31) was noted.
In terms of Shannon
diversity index, increased values were noted for the transect walk method while
decreased values were observed at point count method with reference to baseline
values.
Two exceedances in Action
Level were recorded during this period’s monitoring of birds including
significant declines in species diversity of all avifauna species in the
community; and species diversity of species of conservation importance only.
However, the exceedances were not project-related.
5.2.3.2.1
All Avifauna Species
Point Count
A
total of 22 avifauna species was recorded within the monitoring area using the
point count method. The overall Shannon diversity index during the current
period was H’=2.57.
A significant current
decline at α = 0.05 in the Shannon diversity index was noted relative to the
baseline results of H’=3.13 at α = 0.05. However, the significant decline was
not caused by the construction works of the Project as the concurrently
measured noise level data collected from the different point count locations
during the ecological bird monitoring were still low with a range from 46.6
dB(A) to 61.2 dB(A) only. This decline could be due to the consistent decline
in coverage of intertidal mudflat, consistent increase in coverage of mangrove
and other vegetation from 2000 to 2018 (Sung Y-H et. al., 2021). Moreover,
based on satellite images (2016 to 2020) the mudflat in Shan Pui River adjacent
to Project site was progressively invaded most probably by the fast-growing
exotic mangrove species Sonneratia
spp. as initially reported in the EIA report. The decrease in mudflat coverage
may imply a consequent decrease in foraging area for waterbirds.
Transect Walk
A total of 23 avifauna
species was recorded within the monitoring area using the transect walk method.
The overall Shannon diversity index during the current period was H’=2.99.
Current significant
increase at α = 0.05 in the monitoring results were noted with respect to
baseline values which only noted a total of 1 species and Shannon diversity
index value of H’=0.
5.2.3.2.2
Avifauna Species of Conservation Importance
Point Count
A
total of 6 avifauna species of conservation importance was recorded within the
monitoring area using the point count method. The overall Shannon diversity
index value during the current period was H’=1.04.
Current result showed a
significant decline at α = 0.05 in Shannon diversity index value from the
baseline data. However, as mentioned above, the significant decline was noted
to be caused by other factors and not project-related.
Transect Walk
A
total of 4 avifauna species of conservation importance was recorded within the
monitoring area using the transect walk method. The overall Shannon diversity
index value during the current period was H’=1.28.
However, increases in both
the species richness and Shannon diversity index value relative to the baseline
results were observed during this monitoring period.
5.2.3.2.3
Summary
Summary of the baseline
and impact monitoring species diversity results are shown in Table 5.7
and Table
5.8.
5.2.3.3
Wetland Habitat Utilization
A total of 193 avifauna
individuals (ind.) was noted during the current monitoring period in the
different wetland habitats (i.e. modified watercourse, ponds, mangrove and
reedbed). A slight increase in abundance was noted in this period relative to
the baseline April 2017 results with a total abundance of only 182 ind.
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 species
as evident with the very low to low (VL; and VL-L) abundances in these areas.
With regards to species richness, generally very low to low number (VL; and
VL-L) of species was noted in the different wetland habitats except in the
Active Ponds North to Nullah 2 (M, moderate) in Fung Lok Wai; and Active and
Inactive Ponds in Nam Sang Wai (M-H, moderate to high) (Table
5.9).
5.2.3.3.2
Avifauna Species of Conservation Importance
All of the wetland
habitats were noted with very low abundances 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, majority of
the wetland habitats were also utilized by very low number of species (Table
5.10).
5.2.3.3.3 Overwintering
Avifauna Species
The wetland habitats were
noted with very low abundances of overwintering avifauna species during the
current monitoring period which implied very low utilization of these areas. In
terms of species richness, majority of the wetland habitats were also utilized
by very low number of overwintering species (Table
5.11). The low values recorded during this period might be attributed to
the moving out of the overwintering birds from their wintering grounds
(including the monitoring area) to resume their migration process.
5.2.3.4
Noise Levels
Noise levels LAeq
(30 min) recorded on 17 May 2021 from each of the point count locations during
the ecological bird monitoring are shown in Table 5.12.