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.
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.
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 7x 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 15 December 2023.
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.
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 18:39, 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.
The monitoring
activity was conducted on 15 December 2023 and started around 16:41 (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 (8), Grey Heron Ardea
cinerea (2), Great Egret Ardea alba (1) and Little Egret Egretta
garzetta (1) were observed in pre-roost aggregate
(PRA) around 17:26 at the mudflat east side ANR1 of the Project boundary while
other individuals of Chinese Pond Heron Ardeola bacchus (1) and Grey
Heron Ardea cinerea (1) were concurrently noted at the mudflat northeast
side ANR2 of the Project boundary (Table 17).
For the final
night roost at around 17:53, individuals of Chinese Pond Heron Ardeola
bacchus (18) 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 Grey Heron Ardea
cinerea (1) were noted at ANR2 that utilized the understory 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.
Noise
monitoring activities were conducted on 15 December 2023 in concurrence with
the construction phase monthly monitoring of the pre-identified active night
roosts. Noise monitoring started at 18:30 and lasted for 30 minutes, until 19:00.
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.
No unpredicted
indirect ecological impacts that arose from the project were noted during the
current monitoring period.
Two active
ardeid night roost areas (ANR1 and ANR2) were observed within the Survey Area
during the December 2023 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, Grey
Heron Ardea cinerea, Great Egret Ardea alba and Little Egret Egretta
garzetta.
Both noise
levels at each of the monitoring stations were below the action and limit
levels.
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.
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.
Avifauna
surveys on the different wetland habitats using the transect count and point
count methods were conducted last 4 December 2023 (daytime) which started at
around 07:15 and 15 December 2023 (night-time) which started at around 18:15.
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.
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,
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 4 December
2023 (daytime) which started at around 07:15 and 15 December 2023 (night-time)
which started at around 18:15 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.
An
overall total of 944 avifauna individuals was recorded in the monitoring area
during the December 2023 monitoring period, of which 508 individuals were
recorded from the point count method and 436 individuals from the transect walk
method. Relative to the December 2016 baseline data (point count method = 530;
and transect walk = 85), a decrease in point count method and an increase in
transect walk method were observed.
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.
Of
the 944 avifauna individuals recorded in the monitoring area during the December
2023 monitoring period, 552 individuals (point count method = 319 individuals;
transect walk method
= 233 individuals) were of conservation importance. With
reference to December 2016 data, (point count method = 462; and transect walk =
16), a decrease in point count method and an increase in transect walk method
were observed. 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.
A
total of 61 avifauna species (species richness) were recorded during the December
2023 monitoring period, of which, 53 species were recorded by the point count
method while 45 species were noted by the transect walk method. Relative to the
baseline data (point count method = 35 species; transect walk method = 22
species), an increase in total species richness for both point count method and
transect walk method was noted. In terms of Shannon diversity index (H’)
values, current result in point count method showed a significant increase
(t-value = 9.58; t-crit = 1.96; p-value =3.10E-21; α = 0.05) relative to
the baseline reference value. The current results in the transect walk method
showed a significant increase (t-value = 4.39; t-crit = 1.98; p-value =2.38E-05;
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.
Of
the 61 avifauna species identified during the December 2023 monitoring period, 33
species were of conservation importance (point count method = 28 species;
transect walk method = 24 species). Meanwhile, relative to the baseline values
in December 2016 (point count method = 18 species; transect walk method = 5 species), an increase in the number of species
with conservation importance were recorded from both point count and transect
walk method. In terms of Shannon diversity index (H’), a statistically
significant increase in point count method (t-value = 8.42; t-crit = 1.96;
p-value = 7.12E-17; α = 0.05) and in transect walk method (t-value = 6.67;
t-crit = 2.09; p-value = 1.72E-06; 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.
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.
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 moderate to high (M-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) and low (L) abundance of
avifauna species of conservation importance; and were generally utilized by very
low to low (VL-L) number of species (Table 25).
Noise
levels LAeq (30 min) recorded on 4 December 2023 (daytime) and 15 December 2023
(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.