As the water level falls, birds begin to gather.
Herons, egrets and cormorants mingle with a far rarer visitor, the black-faced spoonbill.
These endangered migrants have travelled the length of the Chinese coastline from Northern China and Korea.
Mai Po marks the end of a 2,000-kilometre journey during which the birds may have lost up to a third of their body weight.
Four hundred black-faced spoonbills, a quarter of the world's population, pass the winter here.
At low water, trapped shrimps and fish become easy prey,
a life saver for these endangered birds.