Mai Po - News Archive

MAI PO UPDATES

From May this year, the six ponds that make up Pond 20 have been drained in turn so that the water inside can be replaced by cleaner rainwater when the typhoon season begins. This work is needed because over the winter, the thousands of ducks that roost in the ponds would cause the water quality to deteriorate and so after the ducks depart in spring, the water inside needs to be replaced.

Apart from draining the ponds, we are also using a backhoe to remove the dense grass that has grown up along the bunds of the ponds. This will open up the pond bunds again and allow them to be used by birds. In future, these bunds will be kept open by regular cutting.

In the same way that the water in Pond 20 has to be replaced after the departure of the wintering ducks, the water in the Waterfowl Collection also needs to be drained in early summer and the pond in the Collection replaced by cleaner rainwater in late summer. We will use this opportunity to carry out maintenance of the Collection, such as repairing any leaks in the bunds.

Over the past couple of year, WWF Hong Kong has been dismantling the large island in gei wai 16/17 and using the soil that has been removed to create a number of smaller and lower islands around the pond. This is because the large islands have never been very successful in attracting a range of birds to use them and overseas experience has shown that smaller islands would be sued by a greater variety of roosting birds, particularly shorebirds.

Work has been completed dismantling two of the islands and this summer, the new smaller islands that have been created have been used quite extensively by breeding Painted Snipe and Black-winged Stilts.

It is proposed that this September, gei wai 16/17 will be drained so that work to dismantle the third and final island can proceed. We will try and complete the work as soon as possible but at least by November, so that the pond can be used by the waterbirds wintering in Deep Bay.

To minimise disturbance to the waterbirds that normally use gei wai 16/17, we will lower the water levels in a number of other gei wai, such as gei wai 11, so that they can compensate for the draining of gei wai 16/17.

One of the problems that Mai Po faces is that of 'old age'. It is natural for coastal wetlands to silt up and gradually turn into dry land. Mai Po is no exception since each time water exchange take place in the gei wai, the incoming water brings silt with it into the pond. This silt settles onto the pond floor and needs to be removed or else the pond will 'dry up'.

As a result, the Reserve's dredger is now busy clearing the silt from the channels around the perimeter of gei wai 7. This pond has not been dredged for over 10 years and the channels have now been colonised and blocked by tall reeds. Work will continue until the end of October when the wintering waterbirds return.