Adaptive Management at Lok Ma Chau Wetland

Conservation Area

Dr. Michael LevenAsia 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 Kowloon-Canton 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 -09Dry 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

Density (mean/ha)LMC

Control Areas

Ratio Density (mean/ha) LMCControlAreas

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

Key: NR – Not recorded within WCA or Control Areas during the periodBlue – Target met (i.e. density in WCA at least twice that in Control Areas)Yellow – Target not met, although density higher than in Control AreasRed – 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 Prickly-leaved Lotus Euryle ferox used to be grown in the Deep Bay area and provided for the specialised habitat needs of Pheasant-tailed Jacana