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 July
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 19:14, 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 25 August
2025 and started around 17:46 (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), Great
Egret Ardea alba (1), Little Egret Egretta garzetta (1)
and Grey Heron Ardea cinerea (1) were
observed in pre-roost aggregate (PRA) around 18:29 at the mudflat east side
ANR1 of the Project boundary while individuals of Chinese Pond Heron Ardeola bacchus (3), Great
Egret Ardea alba (1), Little Egret Egretta garzetta (1)
and Grey Heron Ardea cinerea (4) were
concurrently noted at the mudflat northeast side ANR2 of the Project boundary (Table 17).
For the final night roost at around 18:52,
individuals of Chinese Pond Heron Ardeola bacchus (3), Great Egret Ardea
alba (1) 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 (12), Great Egret Ardea
alba (2), Little Egret Egretta garzetta (2) and Grey Heron Ardea
cinerea (1) 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 25 August 2025 in
concurrence with the construction phase monthly monitoring of the
pre-identified active night roosts. Noise monitoring started at 18:52 and
lasted for 30 minutes, until 19:22.
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 August 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 8 August
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 8 August 2025
(daytime) which started at around 07:15. They 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 371 avifauna individuals were recorded in the
monitoring area during the August 2025 monitoring period, of which 244 individuals
were recorded from the point count method and 127 individuals from the transect
walk method. Relative to the August 2016 baseline data (point count method = 160;
and transect walk = 140), an increase was noted for the point count method and
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 371 avifauna individuals recorded in the monitoring area during
the August 2025 monitoring period, 120 individuals (point count method = 65
individuals; transect walk method = 55 individuals) were of conservation
importance. With reference to August 2016 data, (point count method = 66; and
transect walk = 54), a slight decrease was noted for point count method and a
slight increase for transect walk method. 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 38 avifauna species (species richness) were recorded during
the August 2025 monitoring period, of which, 32 species were recorded by the
point count method while 28 species were noted by the transect walk method.
Relative to the baseline data (point count method = 26 species; transect walk
method = 30 species), increase in total species richness for point count method,
and a slight decrease for transect walk method were recorded. In terms of
Shannon diversity index (H’) values, current result in point count method
showed an increase (t-value = 1.15; t-crit = 1.97; p-value = 2.50E-01; α =
0.05) relative to the baseline reference value. The current results in the
transect walk method also showed an increase (t-value = 0.86; t-crit = 1.97;
p-value = 3.89E-01; 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 38 avifauna species identified during the August 2025 monitoring
period, 14 species were of conservation importance (point count method = 10
species; transect walk method = 12 species). Meanwhile, relative to the
baseline values in August 2016 (point count method = 7 species; transect walk
method = 6 species), an increase in the number of species with conservation
importance were recorded in both point count and transect walk method. In terms
of Shannon diversity index (H’), there is a slight decrease in point count
method (t-value = 0.01; t-crit = 1.98; p-value = 9.92E-01; α = 0.05) and an
increase in transect walk method (t-value = 5.48; t-crit = 1.98; p-value = 2.87E-07;
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 (VL) abundance. In terms of species
richness, different wetland habitats were generally observed with Low (L) or Low
to Moderate (L – M) 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 Very Low (VL) number of
species (Table 25).
5.2.3.4 Noise
Levels
Noise
Levels
Noise levels LAeq (30 min) recorded on 8 August
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.