Environment Agency – Sediment Sampling Assessment

Studies into river restoration often focus on fisheries and the maintenance of viable populations. Many stream spawning species, particularly salmonids (salmon and trout) bury their eggs with gravel for protection, in formations called redds. High levels of sediment runoff from fields and bank erosion infiltrates these gravels, reducing water flow and oxygen supply which dramatically reduces egg survival.

Pre-trap install

Sediment sampling trap

Setting trap

This project replicated a number of similar research studies (River Tamar, McMellin Report) to monitor sediments within river gravels. Two wire baskets were buried in gravel riffles, recently created on the Maxey Cut, River Welland. The methodology attempts to mimic the natural spawning process by constructing artificial redds. The baskets were periodically removed to collect and measure sediment levels.

The results have been aiding longer term studies on sea trout and other migratory fish within the River Welland system.