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 12 May 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 19:13, 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
12 May 2025 and started around 17:54 (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 (9), Little Egret Egretta
garzetta (7) and Grey Heron Ardea
cinerea (1) were observed in pre-roost aggregate (PRA) around 18:30 at the
mudflat east side ANR1 of the Project boundary while individuals of Chinese
Pond Heron Ardeola bacchus
(3), Great Egret Ardea alba (1) and
Little Egret Egretta garzetta (1) were concurrently noted at the mudflat northeast side
ANR2 of the Project boundary (Table 17).
For the final night roost at around 19:13,
individuals of Chinese Pond Heron Ardeola bacchus (11) and Little Egret Egretta garzetta (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 Great Egret Ardea alba (2) and Little Egret Egretta garzetta (2) 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 12 May 2025 in concurrence with the
construction phase monthly monitoring of the pre-identified active night
roosts. Noise monitoring started at 18:54 and lasted for 30 minutes, until 19:24.
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
May 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 19 May 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 19 May 2025
(daytime) which started at around 07:15 and 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 390 avifauna individuals were recorded in the monitoring area
during the May 2025 monitoring period, of which 274 individuals were recorded
from the point count method and 116 individuals from the transect walk method.
Relative to the May 2017 baseline data (point count method = 190; and transect
walk = 2), 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 390 avifauna individuals recorded
in the monitoring area during the May 2025 monitoring period, 118 individuals
(point count method = 91 individuals; transect walk method = 27 individuals) were of
conservation importance. With reference to May 2017 data, (point count method =
71; and transect walk = 2), an increase was noted for both point count 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 37 avifauna species (species
richness) were recorded during the May 2025 monitoring period, of which, 34
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 = 35
species; transect walk method = 30 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 slight decrease (t-value = 1.69; t-crit = 1.97; p-value = 9.23E-02;
α = 0.05) relative to the baseline reference value. The current results in
the transect walk method also showed a significant increase (t-value = 42.93;
t-crit = 1.98; p-value = 1.25E-72; 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 37 avifauna species identified
during the May 2025 monitoring period, 12 species were of conservation
importance (point count method = 11 species; transect walk method = 6 species).
Meanwhile, relative to the baseline values in May 2017 (point count method = 7
species; transect walk method = 1 species), an increase in the number of
species with conservation importance was recorded in both the point count and
transect walk method. In terms of Shannon diversity index (H’), a slight
decrease in point count method (t-value = 1.13; t-crit = 1.98; p-value = 2.58E-01;
α = 0.05) and a significant increase in transect walk method (t-value = 9.78;
t-crit = 2.05; p-value = 2.30E-10; 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 Moderate (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 19 May 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.