Great Ouse foam pollution: Thousands of fish released
Thousands of fish have been released into a river which resembled a "bubble bath" after it was polluted with foam.
An unnamed substance entered the River Great Ouse in Brackley, Northamptonshire, on 29 June, killing thousands of fish and "heavily impacting" invertebrates.
More than 25km of the waterway, between Brackley and Thornton, was affected.
The Environment Agency (EA) has released 8,000 chub in a bid to speed up the river's recovery.
In its recovery plan the EA said: "Ideally we would want to improve the speed of the recovery and capacity of the river to carry aquatic life.
"The river's ecology will recolonise naturally but depending on species and other factors, this could take months to decades."
The fish have been released at Buckingham and the EA said it would be removing barriers which prevent fish from migrating naturally.
There are plans to continue stocking fish, including roach and dace, over the next five years.
After Buckingham, the 140-mile (230km) long river flows through Milton Keynes, Bedford, St Neots, Huntingdon, St Ives, Ely and The Fens before entering The Wash at King's Lynn.