Environment Agency staff are urging anglers to invest in the future of the River Tees by returning their caught salmon to the water.

An adult female Atlantic salmon that weighs five killogrammes spawns once or twice in a lifetime and can lay around 8,000 eggs each time.

From these eggs, only a small proportion will survive the rigours of the freshwater environment, and migration to and from the ocean. On average six fish will return from 8,000 eggs to successfully complete the life cycle.

Environment Agency fisheries officer for the River Tees, David Bamford said: “The status of the salmon stocks in the Tees is at a pivotal point, and it is vital that anglers return the salmon to the river as an investment for the future.

“We need a healthy stock of salmon in the river if the Tees is to fulfil predictions that it will recover to the same extent as the River Tyne which is now one of the best salmon fisheries in England and Wales.”

Staff are currently improving salmon habitats in the Tees river catchment to encourage spawning. This includes introducing spawning gravel on the river bed, and reducing silt from the land which can choke gravel beds and make them useless for spawning.

They also carry out surveys of salmon catches among anglers to find out how many fish return from the sea to the Tees to spawn.

The survey for 2006 showed that anglers returned 67 per cent of the salmon they caught back to the river. Although David says this is welcome news, he wants to see the figure rise to 100 per cent until the Tees achieves its conservation target.

The target has been set down in the Tees Salmon Action Plan which has been produced by the Environment Agency, and identifies the level of angling that the river can sustain whilst also maximising salmon numbers.

Salmon Action Plans have been produced for all significant salmon rivers in England and Wales, at the request of government.