Mai Po Logo: Pied Kingfisher |
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Earthmoving in gei wai 16/17
It was mentioned in the last Mai Po Update, that
the floor of gei wai 16/17 has been silting up over the past
decades because of silt brought into the pond each month when water
exchange takes place. In particular, the floor of the pond in front
of Birdwatching Hide #3 has risen and is now not only difficult to
cover with water but also, easily invaded by grasses so that waterbirds
find it difficult to roost there.
 
The process during the earth moving
works.
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As a result, gei
wai 16/17 was drained from September to November 2003
so that earthmoving works could be carried out to lower this
part of the pond floor. A bulldozer and backhoe was used
to carry out the works and the silt that was removed was
placed along the side of the pond. To quicken the work, a
second tip-up truck was purchased to taken the mud off site.
As a result, the work was completed earlier than expected
and the pond was refilled at the end of November so that
it can be used by wintering waterbirds that were beginning
to return. |
Maintenance of the channels in gei wai 7
The problem of siltation is occurring in all
the Mai Po gei wai. Even before WWF Hong Kong took over management
of gei wai 7 in 1995, the perimeters channels of the pond were
becoming badly silted up due to mud brought into the pond during water
exchange. The channels then slowly became more and more shallow, and
to be invaded by reeds.
In
the past, the original gei wai fishermen at Mai
Po would hire a dredger on pontoon to dredge out the silt
in the channels once every ten or more years. WWF Hong
Kong now has their own dredger and this past summer, the
dredger has been busy de-silting one of the two long channels
in gei wai 7. A greater number of herons, egrets
and other waterbirds are now feeding in this channel, now
that it has been cleared. |
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Dredging works has now stopped in order to minimise
disturbance to the wintering birds but will begin again on the other
long channel in May 2004.
Management works in gei wai 3
Every winter since the late 1990s, there has
been a programme to buy fish of lower commercial value (mainly Tilapia)
from the local pond-fish farmers, to stock into gei wai 3. The
reason for this was in response to the fish farmers' concern that many
of the Cormorants that winter in Deep Bay were taking fish from their
ponds, and so affecting their income. As a result, the stocking of
low value fish into Mai Po is to provide an alternative feeding site
for these Cormorants, to attract them away from the commercial ponds.
From November until March of next year, fish
farmers will be delivering two trucks of fish (approximately 1,500
catties each), every Monday and Thursday for stocking into gei wai 3.
This stocking programme has been attracting
up to 1,000 Cormorants into gei wai 3, along with hundreds of
herons and egrets. To allow visitors a chance to photograph and appreciate
this view, one of the old huts by the slice gate of gei wai 3
has been repaired, and is now opened for use as a birdwatching hide.
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