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 23 October 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°284.25N,
114°141.32E; and 22°2810.43N, 114°142.17E 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 17:48, 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 23 October 2025 and started around 16:52 (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
(3), Great Egret Ardea alba (1) and Grey Heron Ardea cinerea (1) 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
(26), 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 17:48,
individuals of Chinese Pond Heron Ardeola bacchus (42) 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
(3), Great Egret Ardea alba (4), Little
Egret Egretta garzetta (1)
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 23 October 2025 in concurrence with the
construction phase monthly monitoring of the pre-identified active night
roosts. Noise monitoring started at 17:48 and lasted for 30 minutes, until
18:18.
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 October 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 10 October 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 10 October
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 446 avifauna
individuals were recorded in the monitoring area during the October 2025
monitoring period, of which 281 individuals were recorded from the point count
method and 165 individuals from the transect walk method. Relative to the October
2016 baseline data (point count method = 157; and transect walk = 51), an
increase was 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 446 avifauna individuals recorded
in the monitoring area during the October 2025 monitoring period, 170
individuals (point count method = 125 individuals; transect walk method = 45 individuals) were of
conservation importance. With reference to October 2016 data, (point count
method = 107; and transect walk = 35), an increase was 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 44 avifauna species (species
richness) were recorded during the October 2025 monitoring period, of which, 39
species were recorded by the point count method while 33 species were noted by
the transect walk method. Relative to the baseline data (point count method = 32
species; transect walk method = 13 species), significant increase in total
species richness for both point count method and transect walk method were
recorded. In terms of Shannon diversity index (H) values, current result in
point count method showed an increase (t-value = 2.64; t-crit = 1.97; p-value =
8.72E-03; α = 0.05) relative to the baseline reference value. The current
results in the transect walk method also showed an increase (t-value = 6.74;
t-crit = 2.00; p-value = 5.01E-09; 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 44 avifauna species identified
during the October 2025 monitoring period, 13 species were of conservation
importance (point count method = 13 species; transect walk method = 9 species).
Meanwhile, relative to the baseline values in October 2016 (point count method
= 13 species; transect walk method = 3 species), same number of species with
conservation importance was recorded in the point count method and an increase
was recorded for the transect walk method. In terms of Shannon diversity index
(H), there is a slight decrease in point count method (t-value = 1.04; t-crit
= 1.97; p-value = 2.99E-01; α = 0.05) and a significant increase in
transect walk method (t-value = 5.51; t-crit = 1.99; p-value = 4.39E-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 to Low (VL
L) abundance. In terms of
species richness, different wetland habitats were generally observed with High
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 (VL) abundance of avifauna species of conservation importance;
and were generally utilized by Very Low (VL) or Very Low to Low (VLL) number of species (Table 25).
5.2.3.4 Noise
Levels
Noise
Levels
Noise levels LAeq
(30 min) recorded on 23 October 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.