Asian fish found walking River Thames

Birol Koca, an angler, discovered a fish on the Thames Estuary at Woolwich, South East London, which can live out of the water for some time by breathing air.

He said he saw the dead fish on the river bank and knew immediately it was a catfish.

Mr. Koca telephoned the Environment Agency on its 24 hour number straight away and the agency sent an official to authenticate the discovery.

Clarias Batrachus is a freshwater catfish, which can breathe air and is indigenous to South East Asia.

A Fisheries Officer for the Environment Agency, Emma Barton, said this fish can walk on land using its rigid pectoral fins in a back-and-forth body action, and has a lung like organ so it can breathe air on land.

The fish can now often be found in aquaria and leisure fisheries.

If they escape, they pose a risk to the environment by using space and food consumed by native fish.

They can also carry parasites or disease.

It was probably released from an aquarium when it became too big.

The identity of the fish was confirmed by the National Fisheries Technical Team in Cambridgeshire, assisted by the Natural History Museum in London and the Florida Non-Native Fish Laboratory.

Emma Barton said that the angler reacted very conscientiously and has helped the protection of the Thames and the environment.

Some foreign fish species are limited for keeping by the Import of Live Fish Act (ILFA), run by CEFAS (Centre for Environment, Fisheries and Aquaculture Science), because of the possible biological dangers.

Moving fish from one place to another without a permit is illegal and is a serious problem.

The Environment Agency can prosecute those who keep fish illegally under the Salmon and Freshwater Fisheries Act, which carries a fine limited to £2,500.

In Florida, the fish is seen as a major problem.

It was introduced from Thailand in the 1960s.

Florida drivers often stop and wait for great numbers of the fish crawling along the road in search of water.

Woolwich residents hope that they will not see these fish very often.