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 18 March 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 18:34, 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 18 March 2025 and started around 17:33 (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 (4), Great Egret Ardea alba (1) and Grey Heron Ardea cinerea (1) were observed in
pre-roost aggregate (PRA) around 18:01 at the mudflat east side
ANR1 of the Project boundary while individuals of Chinese Pond Heron Ardeola bacchus (12),
Great Egret Ardea alba (10), Little
Egret Egretta garzetta
(3) 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 18:34, individuals of Chinese Pond
Heron Ardeola bacchus
(12), Little Egret Egretta
garzetta (2) and Grey Heron Ardea cinerea (2) 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
(16), Great Egret Ardea alba
(2), Little Egret Egretta
garzetta (2) and Grey Heron Ardea cinerea (6) 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 18 March
2025 in
concurrence with the construction phase monthly monitoring of the
pre-identified active night roosts. Noise monitoring started at 18:34 and
lasted for 30 minutes, until 19:04.
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 March 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 March 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 5 March 2025
(daytime) which started at around 07:15, 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 1057 avifauna individuals were recorded in the monitoring area
during the March 2025 monitoring period, of which 706 individuals were recorded
from the point count method and 351 individuals from the transect walk method.
Relative to the March 2017 baseline data (point count method = 607; and transect
walk = 170), an increase was noted for point count method, while an significant increase 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 1057 avifauna individuals
recorded in the monitoring area during the March 2025 monitoring period, 688
individuals (point count method = 472 individuals; transect walk method = 216
individuals) were of conservation importance. With reference to March 2017 data, (point count method = 510; and transect walk = 44),
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 61 avifauna species (species
richness) were recorded during the March 2025 monitoring period, of which, 55
species were recorded by the point count method while 38 species were noted by
the transect walk method. Relative to the baseline data (point count method = 42
species; transect walk method = 33 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 significant increase (t-value = 9.46; t-crit = 1.96; p-value = 1.58E-20;
α = 0.05) relative to the baseline reference value. The current results in
the transect walk method showed an increase (t-value = 0.89; t-crit = 1.97;
p-value = 0.38; 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 61 avifauna species identified
during the March 2025 monitoring period, 26 species were of conservation
importance (point count method = 23 species; transect walk method = 18
species). Meanwhile, relative to the baseline values in March 2017 (point count
method = 21 species; transect walk method = 8 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
significant increase was noted in point count method (t-value = 5.46; t-crit =
1.96; p-value = 6.10E-08; α = 0.05) and in transect walk method (t-value =
5.18; t-crit = 2.00; p-value = 2.99E-06; 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
Generally 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) number of
species (Table 25).
5.2.3.4 Noise
Levels
Noise levels LAeq
(30 min) recorded on 5 March 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.