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 17 February 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 18:25, 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 17 February 2025 and started around 17:21 (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 (7), Great Egret Ardea alba (2),
Little Egret Egretta garzetta
(1) and Grey Heron Ardea cinerea (1) were observed in
pre-roost aggregate (PRA) around 17:55 at the mudflat east side
ANR1 of the Project boundary while individuals of Chinese Pond Heron Ardeola bacchus (36),
Great Egret Ardea alba (4), Little
Egret Egretta garzetta
(2) and Grey Heron Ardea cinerea (3) were
concurrently noted at the mudflat northeast side ANR2 of the Project boundary (Table 17).
For the final
night roost at around 18:25, individuals of Chinese Pond
Heron Ardeola bacchus
(25), Great Egret Ardea
alba (2) and Grey Heron Ardea cinerea (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
(48), Great Egret Ardea alba
(2), Grey Heron Ardea cinerea (4) and Little Egret Egretta garzetta (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 17 February 2025 in concurrence with the
construction phase monthly monitoring of the pre-identified active night
roosts. Noise monitoring started at 18:25 and lasted for 30 minutes, until 18:55.
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 February 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 5 February 2025 (daytime) and 17 February 2025 (night-time) which started
at around 07:15 and 18:30 respectively. 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 5 February 2025 (daytime) and 17 February
2025 (night-time) which started at around 07:15 and 18:30 respectively, 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 1149 avifauna
individuals were recorded in the monitoring area during the February 2025
monitoring period, of which 702 individuals were recorded from the point count
method and 447 individuals from the transect walk method. Relative to the February
2017 baseline data (point count method = 642; and transect walk = 2),
significant increases were noted for both point count method and 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 1149 avifauna individuals
recorded in the monitoring area during the February 2025 monitoring period, 716
individuals (point count method = 433 individuals; transect walk method = 283
individuals) were of conservation importance. With reference to February 2017 data, (point count method = 447; and transect walk = 2),
a slight decrease was recorded for the point count method, while a significant increase
was noted for the 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 66 avifauna species (species
richness) were recorded during the February 2025 monitoring period, of which, 63
species were recorded by the point count method while 49 species were noted by
the transect walk method. Relative to the baseline data (point count method = 58
species; transect walk method = 1 species), increases in total species richness
for both point count and transect walk method were recorded. In terms of
Shannon diversity index (H’) values, current result in point count method
showed a slight increase (t-value = 0.76; t-crit = 1.96; p-value = 0.4456; α
= 0.05) relative to the baseline reference value. The current results in the
transect walk method showed an increase (t-value = 43.16; t-crit = 1.97;
p-value = 1.62E-161; 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 66 avifauna species identified
during the February 2025 monitoring period, 30 species were of conservation
importance (point count method = 29 species; transect walk method = 19
species). Meanwhile, relative to the baseline values in February 2017 (point
count method = 26 species; transect walk method = 1 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 slight decrease was noted in point count method (t-value = 1.80; t-crit
= 1.96; p-value = 0.0724; α = 0.05) while an increase in transect walk
method (t-value = 23.60; t-crit = 1.97; p-value = 8.01E-69; 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 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 to Low (VL – L) abundance of avifauna
species of conservation importance; and were generally utilized by Low to Moderate
(L – M) and Moderate to High (M
– H) number of
species (Table 25).
5.2.3.4 Noise
Levels
Noise levels LAeq
(30 min) recorded on 5 February 2025 (daytime) and 17 February 2025 (night time)
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.