5.1
Ardeid Night
Roost Monitoring
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.
5.1.2.1 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 8x 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 15 January 2025.
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 16:44,
the earliest final night roost period recorded during the survey and lasted for
30 minutes. Table 16 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.
5.1.3.1 Active Ardeid Night Roost
The monitoring activity was
conducted on 15 January 2025 and started around 17:00
(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, individuals of Chinese Pond Heron Ardeola
bacchus (8), Great Egret Ardea alba (6), Little Egret Egretta garzetta (2) and Grey Heron Ardea cinerea (2) were observed in
pre-roost aggregate (PRA) around 17:31 at the mudflat east side ANR1 of the Project boundary while individuals
of Chinese Pond Heron Ardeola bacchus (14), Great Egret Ardea
alba (2), Little Egret Egretta garzetta (1) and Grey
Heron Ardea cinerea (2) were concurrently noted at
the mudflat northeast side ANR2 of the Project boundary (Table 17).
For the final night roost
at around 17:59, individuals of Chinese
Pond Heron Ardeola bacchus
(7), Great Egret Ardea alba (1) and Grey Heron Ardea cinerea (2) were observed at the roosting area ANR1
utilizing the understory to canopy layer of the roosting substrate Sonneratia apetala and S. caseolaris; while other individuals of Chinese Pond
Heron Ardeola bacchus
(36), Great Egret Ardea alba (1), Grey Heron Ardea cinerea (3) and Little Egret Egretta garzetta (2) were noted at ANR2 that
utilized the understory to 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 15 January 2025 in concurrence with the construction phase monthly
monitoring of the pre-identified active night roosts. Noise monitoring started
at 17:59 and lasted for 30 minutes, until 18:29.
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 18.
No Action / Limit exceedance was recorded for noise
levels at stations (NMS1 and NMS2) in close proximity to the two active ardeid night
roosts (ANR1 and ANR2) observed within the Survey Area during the reporting
month.
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.
5.1.5.1 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 January
2025 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 Ardeola bacchus, Great Egret Ardea
alba, Little Egret Egretta garzetta and Grey Heron Ardea
cinerea.
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
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.
5.2.2.1 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 last 7 January 2025 (daytime) which started at around 07:15.
Additionally, the survey overlooking the mudflats and mangroves in the Shan Pui River was concurrently conducted on the same date with
the daytime survey during the low tide (generally 1.5m or below) period, and
also started at around 07:15. 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.
Results of the avifauna
survey on the different habitats within the monitoring area using the transect
count and point count methods as conducted last 7 January 2025 (daytime) which
started at around 07:15 is 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 07:15 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 1349
avifauna individuals were recorded in the monitoring area during the January
2025 monitoring period, of which 1003 individuals were recorded from the point
count method and 346 individuals from the transect walk method. Relative to the
January 2017 baseline data (point count method = 708; and transect walk = 347),
an increase was noted for point count method while a slight decrease was noted
for transect walk method.
Details of these findings are summarized in Table 20.
No Action / Limit exceedance was recorded for the abundance of all
avifauna species (including but not limited to overwintering waterbirds) for
both the point-count and transect walk method.
5.2.3.1.2 Avifauna Species of Conservation
Importance
Of the 1349 avifauna
individuals recorded in the monitoring area during the January 2025 monitoring
period, 1012 individuals (point count method = 795 individuals; transect walk
method = 217 individuals) were of
conservation importance. With reference to January 2017 data, (point count
method = 528; and transect walk = 83), increases were noted for both the point
count and transect walk methods. Details of these findings are summarized in
Table 21.
No Action / Limit exceedance was recorded for the abundance of avifauna
species with conservation importance only for both the point-count and transect
walk method.
5.2.3.2 Diversity (Species Richness1
and Shannon Diversity Index2)
5.2.3.2.1 All Avifauna Species
A total of 56 avifauna
species (species richness) were recorded during the January 2025 monitoring
period, of which, 49 species were recorded by the point count method while 48
species were noted by the transect walk method. Relative to the baseline data
(point count method = 47 species; transect walk method = 50 species), a slight increase
in total species richness for point count method while a slight decrease in
transect walk method were recorded. In terms of Shannon diversity index (H’) values,
current result in point count method showed a slight decrease (t-value = 0.74;
t-crit = 1.96; p-value = 4.62E-1; α = 0.05) relative to the baseline
reference value. The current results in the transect walk method showed a decrease
(t-value = 1.89; t-crit = 1.96; p-value = 0.059; α = 0.05) from baseline
reference value. Details of these findings are summarized in Table 22, Appendix F.6.1, and Appendix F.6.2.
No Action / Limit exceedance was recorded for the decline in species
diversity of all avifauna species in the point count / transect walk method.
5.2.3.2.2 Avifauna Species of Conservation
Importance
Of the 56 avifauna species
identified during the January 2025 monitoring period, 24 species were of
conservation importance (point count method = 24 species; transect walk method
= 18 species). Meanwhile, relative to the baseline values in January 2017
(point count method = 22 species; transect walk method = 11 species), increases
in the number of species with conservation importance for both the point count
method and the transect walk method were recorded. In terms of Shannon diversity
index (H’), a decrease was noted in point count method (t-value = 1.40; t-crit
= 1.96; p-value = 0.16; α = 0.05) while a significant increase in transect
walk method (t-value = 3.56; t-crit = 1.98; p-value = 4.96E-4; α = 0.05)
was observed relative to the baseline reference values. Details of these findings
are summarized in Table 23, and Appendix F.6.3.
No Action / Limit exceedance was recorded for the decline in species
diversity of avifauna species with conservation importance in the point count /
transect walk method.
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 reed bed.
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 Low to Moderate (L – M) abundance. In terms of
species richness, different wetland habitats were generally observed with Hight
to Very High (H – VH) number of species (Table 24).
5.2.3.3.2 Avifauna Species of Conservation
Importance
Majority of the different
wetland habitats had Very Low to Low (VL – L) abundance of avifauna
species of conservation importance; and were generally utilized by Very Low (VL) number of species (Table 25).
5.2.3.4 Noise Levels
Noise levels LAeq (30 min) recorded on 7 January 2025 (daytime) from
each of the point count locations during the ecological bird monitoring are
shown in Table 26.
No Action / Limit exceedance was recorded for noise levels at all
stations for the ecological monitoring of birds in the reporting month.