Numbers hit by global warming and loss of nest sites; floating water plantain is increasingly under threat from the re-opening of canals to heavy traffic.
Mr Leese said the area had a large floating population which had the potential of masking the activities of anyone who wanted to remain unnoticed.
He is now leading a Ford Foundation-sponsored project on education of the floating population which kicked off earlier this year.
Experts said that with social development, the floating population has increased, placing a lot of pressure on the social order.
Some analysts said the reason for the sharp rise in robberies was due to an increase in the floating populations of some large cities and more illegal drug use.
The Spring Festival is the biggest festival for family reunions, drawing many of the floating population and workers to their homes in other provinces.
An open-air debate with Solomon Pappiya as the moderator, near bus stands and public places in rural areas, is meant to target the floating population.
Aquatics with floating leaves, water lilies included, also need yearly attention.
She tossed a floating toy into the water for her dog to fetch over and over.
While surfing the Internet to check on the floating population, police found that Li was renting a house in the district.