Transcript Adaptive Management at Lok Ma Chau Wetland Conservation Area

Adaptive Management at
Lok Ma Chau Wetland
Conservation Area
Dr. Michael Leven
Asia Ecological Consultants Ltd.
Lok Ma Chau Wetland Compensation Area
• Environmental Impact Assessment for the Lok Ma
Chau Spur Line and Station was approved in 2002
by Hong Kong SAR Government.
• A condition of approval was that the KowloonCanton Railway Company would enhance an area
of commercial fishponds at Lok Ma Chau adjacent
to the new station site to compensate for the
habitat loss and disturbance caused by the station
and railway construction and operation.
Management Objectives of the LMC WCA
• Enhancement of 35.25 ha of former commercial fishponds by:
– enlarging small ponds to reduce enclosure effects;
– reprofiling of fishpond bunds to provide shallow sloping
margins to increase feeding opportunities and the
availability of fish and invertebrate prey to birds;
– establishing marginal emergent vegetation;
– manipulating fish stocking, feeding/fertilising regime and
drain-down to optimise food availability to birds; and
– wetland habitat diversification by creating areas of
freshwater marsh and reedbeds.
Target Species
• 26 bird species (including Black-faced Spoonbill)
• Eurasian Otter
• Herpetofauna and dragonflies
Quantitative numerical targets are set for bird species –
number of individuals per hectare twice that of
representative Control Areas of commercial fishponds
Lok Ma Chau WCA Original Conditions
2002
Lok Ma Chau WCA –
Current Land Use
2007
General Management Works in the Dry Season
• Water quality control
• Weekly trash fish stocking
• Vegetation management
– Routine grass cutting
– Control of undesired species
• Control on-site access to minimize disturbance
General Management Works in the Wet Season
• Pond management and/or modification where
necessary
• Trash fish stocking for winter food
• Vegetation management
• Control of pest species
– Adult apple snail removal (~1,200 kg removed in first
half of 2008) and removal of egg masses
– Red Imported Fire Ants
Island Creation By Importing Fill
Island and Shallows Creation By
Recontouring
Marsh Creation : Recontouring
Marsh Creation : Planting
Marsh Creation : Establishment
Water quality treatment to neutralise acid
soil is essential: lime and peanut residue
are used
Stocking with “trash” fish: <10 cm Tilapia
and Goldfish
Drain-down
Active management is required!
Scheduled Management Works for 2008 -09
Dry Season
• Continue with routine grass cutting and
vegetation management
• Seedling tree control
• Fish stocking: 1000 kg per week
• Control of water quality
Scheduled Management Works for 2009 Wet
Season
• Pond modification where necessary (Ponds 8 & 9)
• Vegetation Management
–
–
–
–
Routine grass cutting and vegetation management
Replacement tree, shrub and bamboo planting
Seedling tree control
Polygonum transplanting and establishment monitoring
• Fish stocking for winter food
• Control of water quality
• Red Imported Fire Ants nest treatment
Wildlife Targets
Bird Targets 12 months up to 30th Nov 2008
LMC
Control
Areas
Ratio
Density (mean/ha)
LMC
Control
Areas
Ratio
Great Cormorant
4.25
0.30
14.29
Greater Painted-snipe
0.022
0.000
LMC
Grey Heron
3.20
0.15
21.74
Black-winged Stilt
0.166
0.024
7.04
Great Egret
1.15
0.54
2.15
Pintail/Swinhoe's Snipe
0.009
0.000
19.12
Little Egret
1.18
0.75
1.58
Common Snipe
0.090
0.011
8.31
Chinese Pond Heron
0.42
0.43
1.00
Richard's Pipit
0.060
0.041
1.48
Black-faced Spoonbill
0.46
0.02
27.61
Bluethroat
0.002
0.000
3.37
Common Teal
1.331
0.030
44.40
Common Stonechat
0.112
0.038
2.93
Greater Spotted Eagle
0.001
0.000
LMC
Pallas's Grasshopper Warbler
0.016
0.001
13.49
Imperial Eagle
0.001
0.000
LMC
Zitting Cisticola
0.172
0.104
1.64
Eurasian Hobby
*
0.000
-
Japanese Yellow Bunting
0.000
0.000
nr
Japanese Quail
0.000
0.000
nr
Red-billed Starling
2.008
1.544
1.30
Eurasian Coot
0.006
0.000
LMC
Black-naped Oriole
0.005
0.000
LMC
Pheasant-tailed Jacana
0.019
0.000
LMC
Density (mean/ha)
Key:
NR – Not recorded within WCA or Control Areas during the period
Blue – Target met (i.e. density in WCA at least twice that in Control Areas)
Yellow – Target not met, although density higher than in Control Areas
Red – Target not met and density lower than in Control Areas
* Casual observation only
Conservation benefits of the Lok Ma Chau WCA
•
For large waterbirds such as ardeids and Black-faced Spoonbills
this is an additional feeding area providing an alternative to
established locations at Mai Po NR and the Deep Bay Mudflats,
especially important as use of commercial fishponds does not
appear to be increasing despite the rise in the Deep Bay wintering
population;
•
Provision of alternative wetland microhabitats such as freshwater
marsh and reedbed provides habitat for a much wider range of
species than the original fishponds, including a number of species
which are locally or globally threatened;
•
As an actively managed site it is possible to undertake specific
initiatives directed at the needs of particular species.
Benefits for species with special
microhabitat requirements
• Many wetland species
present in Deep Bay do
not use fishponds. For
example, the globally
endangered Imperial
Eagle ranges widely in
the area but feeds
almost entirely on
ducks and ducks
rarely use fishponds
Habitat creation initiatives
• Lotus ponds – a lost
habitat in Hong Kong
– are being recreated
at LMC; the Pricklyleaved Lotus Euryle
ferox used to be
grown in the Deep
Bay area and
provided for the
specialised habitat
needs of Pheasanttailed Jacana