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 14 April 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 18:44, 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 14 April 2025 and started around 17:43 (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 (2) and Little Egret Egretta garzetta (2) were observed in
pre-roost aggregate (PRA) around 18:22 at the mudflat east side ANR1 of the
Project boundary while individuals of Grey Heron Ardea
cinerea (8) and Great Egret Ardea alba
(19) were concurrently noted at the mudflat northeast side ANR2 of the Project
boundary (Table 17).
For the final
night roost at around 18:54, individuals of Chinese Pond Heron Ardeola bacchus (2)
and Little Egret Egretta garzetta (1) 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 (2), Great Egret Ardea
alba (7) and Grey Heron Ardea cinerea
(3) 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 14 April 2024 in concurrence with the construction phase monthly monitoring of the
pre-identified active night roosts. Noise monitoring started at 18:54 and
lasted for 30 minutes, until 19:24.
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 April 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 were
conducted last 16 April 2025 (daytime) which started at
around 07:15 and 14 April 2025 (night-time) which started around 19:00.
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 16 April
2025 (daytime) which started at around 07:15 and 14 April 2025 (night-time)
which started at around 19:00 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 07:15 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 492 avifauna individuals were recorded in the monitoring area
during the April 2025 monitoring period, of which 322 individuals were recorded
from the point count method and 170 individuals from the transect walk method.
Relative to the April 2017 baseline data (point count method = 298; and
transect walk = 47), increases were noted for both the point count and transect
walk methods.
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 492 avifauna individuals recorded
in the monitoring area during the April 2025 monitoring period, 240 individuals
(point count method = 153 individuals; transect walk method = 87 individuals) were of
conservation importance. With reference to April 2017 data, (point count method
= 200; and transect walk = 1), a decrease was noted for point count method, while
an increase in transect walk method was observed. 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 54 avifauna species (species
richness) were recorded during the April 2025 monitoring period, of which, 50
species were recorded by the point count method while 35 species were noted by
the transect walk method. Relative to the baseline data (point count method =
41 species; transect walk method = 13 species), increases in total species
richness for both transect walk count and point count methods were recorded. In
terms of Shannon diversity index (H’) values, current result in point count
method showed an increase (t-value = 1.50; t-crit = 1.96; p-value = 1.34E-01;
α = 0.05) relative to the baseline reference value. The current results in
the transect walk method also showed a significant increase (t-value = 6.11;
t-crit = 1.99; p-value = 5.24E-08; 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 54 avifauna species identified
during the April 2025 monitoring period, 20 species were of conservation
importance (point count method = 17 species; transect walk method = 14
species). Meanwhile, relative to the baseline values in April 2017 (point count
method = 13 species; transect walk method = 1 species), an increase in the
number of species with conservation importance was recorded in both the point
count and transect walk method. In terms of Shannon diversity index (H’), a
slight decrease in point count method (t-value = 1.89; t-crit = 1.97; p-value =
6.02E-02; α = 0.05) and a significant increase in transect walk method
(t-value = 21.09; t-crit = 1.99; p-value = 5.79E-36; α = 0.05) were noted
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 Very Low to Low (VL
- L) abundance. In terms of species richness, different wetland habitats were
generally observed with Moderate (M) or Very high (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 (VL) abundance of avifauna species of conservation
importance; and were generally utilized by Low (L) number of species (Table 25).
5.2.3.4 Noise
Levels
Noise levels LAeq
(30 min) recorded on 14 April 2025 (night time) and 16 April 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.