Demand for exotic aquarium pets is enabling fish, plants and snails to become established in New Zealand waterways.
National Institute of Water and Atmospheric Research (NIWA) scientist John Clayton is monitoring a range of exotic species including the ear pond snail, which has quickly become widespread through many of Rotorua's lakes and has now also been found in the remote Ashburton Lakes in the Southern Alps.
Dr Clayton says the only way these snails, and other exotic fish and plant species, can end up in lakes in the first place is if they are released.
He says sometime people get tired of looking after their aquariums and release the contents into the nearest water body.
