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 14 July 2025 and started around 18:10
(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) and Little Egret Egretta garzetta (11) were observed in
pre-roost aggregate (PRA) around 18:32 at the mudflat east side ANR1 of the
Project boundary while individuals of Chinese Pond Heron Ardeola
bacchus (8), Great Egret Ardea
alba (3) and Little Egret Egretta garzetta (8) were concurrently noted
at the mudflat northeast side ANR2 of the Project boundary (Table 17).
For the final night roost at around 19:14,
individuals of Chinese Pond Heron Ardeola bacchus (31), Great Egret Ardea
alba (1) and Little Egret Egretta garzetta (13) 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), Little Egret Egretta garzetta (5) 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 14 July 2025 in concurrence with the construction
phase monthly monitoring of the pre-identified active night roosts. Noise
monitoring started at 19:14 and lasted for 30 minutes, until 19:44.
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 July 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 July 2025 (daytime) and 14 July 2025
(night-time) which started at around 07:15 and 19:30. 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 July 2025 (daytime) and 14 July 2025
(night-time) which started at around 07:15 and 19:30. 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 393 avifauna individuals were recorded in the
monitoring area during the July 2025 monitoring period, of which 274 individuals
were recorded from the point count method and 119 individuals from the transect
walk method. Relative to the July 2017 baseline data (point count method = 165;
and transect walk = 36), 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 393 avifauna individuals recorded in the monitoring area during
the July 2025 monitoring period, 113 individuals (point count method = 91
individuals; transect walk method = 22 individuals) were of conservation importance. With reference to July
2017 data, (point count method = 80; and transect walk = 8), increases were
noted for both point count method and 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 41 avifauna species (species richness) were recorded during
the July 2025 monitoring period, of which, 37 species were recorded by the
point count method while 26 species were noted by the transect walk method.
Relative to the baseline data (point count method = 26 species; transect walk
method = 18 species), an increase 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 a significant increase
(t-value = 4.30; t-crit = 1.97; p-value = 2.30E-05; α = 0.05) relative to
the baseline reference value. The current results in the transect walk method
also showed an increase (t-value = 1.54; t-crit = 2.00; p-value = 1.29E-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 41 avifauna species identified during the July 2025 monitoring
period, 13 species were of conservation importance (point count method = 13
species; transect walk method = 5 species). Meanwhile, relative to the baseline
values in July 2017 (point count method = 5 species; transect walk method = 3
species), an increase in the number of species with conservation importance was
recorded in the point count and transect walk method. In terms of Shannon
diversity index (H’), a significant increase in point count method (t-value = 6.38;
t-crit = 1.97; p-value = 1.79E-09; α = 0.05) and an increase in transect
walk method (t-value = 1.23; t-crit = 2.11; p-value = 2.37E-01; 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 to Moderate
(L – M) or High (H) 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 to Low (VL
– L) number of
species (Table 25).
5.2.3.4 Noise
Levels
Noise
Levels
Noise levels LAeq (30 min) recorded on 16 July
2025 (daytime) and 14 July 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.