The Manatee : Ecology and Use for Weed Control

SINCE 1885 the Botanic Gardens in Georgetown, British Guiana, has had in some ornamental pools manatees ( Trichechus manatus , order Sirenia), which have been always fed with grass by visitors. These pools have been kept clear by the manatees and it seemed always necessary to get additional food in the form of grass. It was therefore felt that experiments should be proceeded with using these animals for weed control, and some have been maintained in the reservoirs of the water purification plant and have effectively kept these clear of aquatic plants, particularly Cabomba aquatica, Anacharis, Leersia, Utricularia .