Salmon and sea trout have been given a boost with the creation of new spawning beds on  the River Tamar.

Research by the Environment Agency has revealed a shortage of good quality clean river gravels in areas such as the Upper Tamar. An absence of suitable gravel beds makes it difficult for salmon and sea-trout to spawn and can result in a decline in fish stocks.

Like many salmon rivers, the Tamar has a ‘Salmon Action Plan’ that pinpoints the main threats to local salmon stocks and helps the Agency decide how best to boost fish numbers. The plan includes something called a conservation limit. This is a target for the number of salmon eggs needed to ensure enough young salmon survive in the river to sustain a healthy population.

‘Last year the Tamar only just met its target of 11.5 million eggs, so it is important we take action and provide salmon with new areas to spawn. Old gravel beds can become silted up making them unsuitable or washed away in floods,’ said Lesley Newport for the Environment Agency.

This week fisheries officers started work constructing new spawning beds at Tetcott near Holsworthy, Devon. The gravel, mostly granite, is specially selected and cleaned before being carefully placed on the riverbed. The granite is mixed with a smaller quantity of re-cycled material including pebbles originally dredged from the sea.

The spawning bed is shaped into something called a ‘Newbury Riffle’. This is a streamlined design recommended by the Atlantic Salmon Trust that encourages the correct flow over the gravels and ensures the fish eggs are kept in oxygenated water until they hatch in the spring.

The new beds also create valuable habitat for all stages of young fish. The erection of fencing on the adjoining riverbank helps to ensure the beds are kept clean from silt from field run-off and livestock in the river.

The gravel beds are the latest in a series of improvements carried out on the Tamar by the Environment Agency as part of the river’s Salmon Action Plan. They have been welcomed by Anne Voss-Bark, Chairman of the Tamar and Tributaries Fisheries Association who said, ‘This work is of fundamental importance to the recovery of salmon stocks in the Tamar. I am delighted the Agency is taking this initiative.’

‘We have already seen adult salmon spawn on a trial bed we created last year. Recent surveys have shown a good increase in young salmon at the site. The Tetcott area is a wonderful stretch of the Tamar with abundant wildlife. We are grateful to the landowners and riparian owners who have helped us carry out this important environmental improvements work,’ said Lesley Newport.