Joe with schoolchildren by a river
Media playback is unsupported on your device

Schools breed their own rare fish

9 April 2012 Last updated at 10:57 BST

Children from seven schools in London have been rearing their own endangered fish as part of a school project.

The children have been breeding rare 'brown trout hatchlings', and it's taken them three months.

They're doing it to get hundreds more trout back in the Wandle, a river in London.

In the past, all the trout there had died because of pollution.

Watch Joe's report as he joins them on their mission.