An ornamental plant recently introduced into Samoa is threatening freshwater species on the north coast of Upolu Island.
The Ministry of Environment has warned residents in Faleata and Vaimauga of the dangers posed by the water lettuce, which is admired for its large fan-like leaves and light green colour.
The ministry says it was introduced before 2012 and planted in pots and ponds.
But it says water lettuce is an aquatic weed which can spread very rapidly in water and threaten native freshwater plants and fish.
It can also restrict water flow, hinder swimmers and boat operators, and threaten drinking water sources and hydroelectricity supplies.
The ministry also says removal is hard and expensive.
Photo: Corbis