6.
ECOLOGY
6.1.1 The objectives of the ecology monitoring are:
a) To verify the accuracy of the impact predictions;
b) To check if the recommended mitigation measures are implemented fully;
c) To examine the effectiveness of the recommended mitigation measures;
d) To check whether the residual impacts comply with relevant ecological requirements; and
e) To recommend timely action plans to rectify any unacceptable impacts.
6.2.1 The ecological monitoring parameters are the following:
• Construction and operational stage impacts on habitats of ecological importance within and outside the construction site boundary;
• Construction and operational stage impacts on vegetation and fauna within and outside the construction site boundary;
• Performance of construction and operational stage mitigation measures.
6.3.1
The
following equipment is required for ecological monitoring:
a)
General:
field note books and survey forms, camera (film or digital);
b)
Bird
monitoring: binoculars; magnification 7 – 10x;
c)
Vegetation
monitoring: 50 cm quadrate and/or 50 cm rule.
6.4.1 The monitoring areas are shown in Figure 6.1. These extend for 60 m on either side of the existing channel as well as the proposed bypass culvert. The 60 m radius has been selected for the survey corridor as it is considered that should any adverse impacts on habitats or species occur as a consequence of the project it is unlikely that the impacts will extend materially beyond this distance from the works area. Within these areas monitoring should focus on the area around the Ho Pui and Ma On Kong egretry and habitats of at least moderate ecological importance. In addition, monitoring should be undertaken at the Ho Pui egretry and Ma On Kong egretry. The Ma On Kong egretry is outside the survey corridor but monitoring should be conducted in order to identify any adverse effects on the breeding egrets.
6.5.1 Baseline ecological monitoring should be agreed with the Agriculture, Fisheries and Conservation Department (AFCD). Monitoring methodologies should follow these detailed below, but the contractor should submit the monitoring methodologies for approval prior to their commencement. The baseline monitoring should be performed within the monitoring areas as shown in Figure 6.1 and should be undertaken prior to the commencement of construction works to:
a) update habitat maps to show current conditions throughout the monitoring area;
b) establish a vegetation photographic record within the monitoring area. The photographic record should be sufficiently detailed to allow identification of individual trees (where these are isolated) or the extent of tree clumps (where there is a closed tree canopy); and
c) conduct a walk-through survey of the monitoring areas in order to identify changes which have taken place since the EIA survey (in particular the Ho Pui Egretry) which can be predicted to possibly or probably have had an impact on fauna distribution or numbers.
Construction
Stage
6.6.1 Construction stage monitoring at areas shown in Figure 6.1 should cover the following:
a) Vegetation Monitoring:
(i) Monthly monitoring should be conducted by means of a walk-through survey along the boundary of the works area to confirm that there are no adverse impacts on habitats outside the site in particular the Conservation Area (CA) zone and Ho Pui Egretry.
(ii) A photographic record should be made at six monthly intervals and checked against the baseline record.
b) Fauna Monitoring:
(i) Monthly monitoring of all bird numbers including wetland species and species identified as being of conservation importance. Bird surveys should commence no later than two hours after dawn. Habitats utilised should be recorded.
(ii) Bi-weekly monitoring of the Ho Pui egretry for the period from 1st of March to end of May. Number of active nests, species and number of birds present and, breeding stage (nest building, incubation, feeding young) should be recorded. Counts should be undertaken so as not to cause disturbance to nesting egrets; details of breeding stage should only be collected where these can be undertaken with no additional disturbance being caused. The timing of egretry monitoring is intended to cover the early period when egrets might be nesting (because of early warming up weather in recent years which may lead to some egrets preparing for nesting as early as March). Should no egret nest be found at the Ho Pui egretry by the end of May, monitoring frequency from June to August can be downgraded to monthly. However, if nests are found at Ho Pui egretry, bi-weekly monitoring should be carried on till the end of August. Monthly monitoring should be conducted at the Ma On Kong egretry from March to August to provide reference information on the breeding egrets nearby. Before commencement of the monitoring (and any subsequent changes to the monitoring parameters), it should be proposed by the ET Leader, verified by the IEC and submitted to AFCD for approval (and copied to EPD for information).
(iii) Flight line surveys to record feeding areas and habitats used by breeding egrets should be undertaken twice per month during the period from April to June. The timing of flight line surveys has been selected to cover the main part of the breeding season as these surveys are intended to provide a representative sample of the feeding destinations of egrets using the egretry (hence they are undertaken when the largest number of birds is likely to be present).
Operational
Stage
6.6.2 Operational monitoring should be undertaken within the monitoring areas (Figure 6.1) for a period of one year upon completion of the construction. The monitoring should cover the following:
a) Vegetation Establishment:
(i) Quarterly vegetation establishment should be monitored along the stream sections lined with gabions to confirm continued recovery of vegetation cover through dry and wet seasons.
(ii) Survey should be by means of quadrates of 50 cm diameter across the stream channel covering gabion sides and stream bottom. Survey should cover percentage cover, species present and species condition including height, whether flowering or fruiting and any evidence of damage or restrictions to growth arising from the growth medium or any maintenance activities. During the first survey quadrate positions should be marked in order to identify their positions for subsequent surveys and a photograph should be taken showing the marker in situ in order to permit re-establishment of the quadrate position in the event of the marker being lost.
(iii) The timing and frequency of vegetation establishment surveys has been chosen because the primary purpose of these surveys is to assess the success of natural (re)colonization of the channel sides by semi-natural riparian vegetation. A survey in the latter part of the wet season will show both the diversity of the plant community when most species are at their seasonal maximum size and will also permit assessment as to how the established vegetation has withstood the effects of wet season spates.
(iv)
Vegetation monitoring is
considered important because relatively little is known in
b) Fauna Monitoring:
(i) Monthly monitoring of all bird numbers; for wetland species and species identified as being of conservation importance. Habitats utilized should be recorded and birds utilizing the channel, the gabion banks and its immediate environs should be distinguished from those using the wider survey area. Monitoring should be by means of a walk-through survey along the length of the channel.
(ii) Monthly monitoring of the Ho Pui and Ma On Kong egretries for the period from March to August. Number of active nests, species and number of birds present and, breeding stage (nest building, incubation, feeding young) should be recorded. Counts should be undertaken so as not to cause disturbance to nesting egrets; details of breeding stage should only be collected where these can be undertaken with no additional disturbance being caused.
(iii) Flight line surveys to record feeding areas and habitats should be undertaken twice per month during the period from April to June.
6.7
Event and Action Plan for Ecology
6.7.1 Water quality data for monitoring stations W2 and W3 should also be used for reference while undertaking ecological monitoring purposes. These values are based on absolute values for survival of ecological resources, and changes in water quality which trigger an impact on the biological community. Should the monitoring results of water quality parameters at any designated monitoring stations exceed the criteria, the actions in accordance with the Action Plan shall be carried out.
6.7.2
Monitoring
of ecological criteria must be used as a basis for remedial action if such
monitoring shows that adverse effects on habitats or species numbers and
diversity exceed predictions. For this project, its nature is such that it is
unrealistic to expect wildlife to continue to use the portions of the stream to
be channelised during the construction period. Monitoring during the
construction period is, therefore, focussed on safeguarding of the Ho Pui
egretry and the use of adjoining wetland by wetland species of conservation
importance (including egrets from the Ho Pui and Ma On Kong egretries).
6.7.3
During the
operational period, monitoring will cover the following aspects:
•
Vegetation
establishment and development on the gabion banks
•
Wildlife
use of the channels
•
Wildlife
use of adjoining wetland areas.
•
Success of
the Ho Pui and Ma On Kong egretries.
6.7.4
In view of
the relatively limited experience in Hong Kong on the use of gabions to
maintain or restore the streamside habitats (as opposed to their use for slope
stabilisation or landscape purposes where different vegetation establishment
objectives apply), it is not considered appropriate to set action or limit
levels for vegetation establishment and species diversity at the present time.
Rather, these criteria should be monitored and assessed in parallel with
observations of faunal use and the findings applied adaptively in setting
action and limit levels after the first year of monitoring. These findings will
also be applied to the long-term vegetation management and maintenance regime
for the channels.
6.7.5
With
respect to action and limit levels for faunal diversity and numbers, it is
necessary to set levels which trigger appropriate management actions. However,
in the present case, the number of species and individuals using the channels
and the adjoining wetlands are too low and variable to permit such levels to be
set using rigorous methods. Numbers of nesting egrets at most egretries also
vary from year to year (for
example, due to differences in the weather during the early part of the
breeding season). Accordingly, action and limit levels have been set to trigger
a review of reasons why breeding egret numbers or wetland bird numbers using
adjoining wetlands may have declined.
Action and Limit Levels for
Ecology
|
Parameters |
Action level |
Limit level |
|
Construction
phase (adjacent wetland areas) |
|
|
|
Decrease in
number of breeding egrets since previous year |
> 20% |
>40% |
|
Operational phase (channels) |
|
|
|
Vegetation
cover on gabion banks |
Set after first quarter |
Set after first quarter |
|
Vegetation
diversity on gabion banks |
Set after first quarter |
Set after first quarter |
|
Operational phase (adjacent wetland areas) |
|
|
|
Decrease in
number of species of wetland birds of conservation importance from baseline |
> 20% |
>40% |
|
Decrease in
the total numbers of wetland birds of conservation importance from baseline |
>20% |
>40% |
Event/Action
Plan for Ecology
|
EVENT |
ACTION |
|||
|
ET Leader |
IEC |
Engineer |
Contractor |
|
|
ACTION LEVEL REACHED |
1.
Carry out investigation 2.
Review results and assess whether
amendment to action level is appropriate 3.
Report the results of
investigation to the IEC 4. Notify Contractor and Engineer 5. Discuss with the Contractor and
formulate remedial measures 6. Repeat
survey to confirm results |
1.
Review the analysed results
submitted by ET 2.
Review the proposed remedial
measures by the Contractor and advice the Engineer accordingly 3. Supervise
implementation of remedial measures |
1.
Confirm receipt of notification
of failure in writing 2.
Notify Contractor 3.
Require Contractor to propose
remedial measures for the analysed problem 4. Ensure
remedial measures properly implemented |
1.
Take immediate
action to avoid further problem 2.
Submit proposals for remedial
actions to IEC within 3 working days of notification 3.
Implement the agreed proposals 4. Resubmit
proposals if problem still not under control |
|
LIMIT LEVEL REACHED |
1.
Carry out investigation 2.
Review results and assess whether
amendment to limit level is appropriate 3.
Report the results of
investigation to the IEC 4.
Notify Contractor and Engineer 5.
Discuss with the Contractor and
formulate remedial measures 6.
Repeat
survey to confirm results |
1. Review the analysed results submitted by ET 2. Review the proposed remedial measures by the Contractor
and advice the Engineer accordingly 3. Supervise implementation of remedial measures |
1. Confirm receipt of notification of failure in writing 2. Notify Contractor 3. Require Contractor to propose remedial measures for the
analysed problem 4. Ensure remedial measures properly implemented 5. Issue instruction to stop the relevant portion of the
works until the problem is abated (construction period only). |
1. Take immediate action to avoid further problem 2. Submit proposals for remedial actions to IEC within 3
working days of notification 3. Implement the agreed proposals 4. Resubmit proposals if problem still not under control 5. Stop the relevant portion of works as determined by the
Engineer until the problem is abated (construction period only) |