The plight of European eels (Anguilla anguilla) is well known to most people who work in fisheries. Fishtek developed a product to address the problem presented by tidal gates and flaps, which prevent the movement of juvenile eels (elvers) from moving up into rivers and streams from the sea. This product, called the Tidal Gate Damper (TGD) has been used at several sites and has been shown to be effective at significantly increasing the opportunity for eels to move past these structures on their onward migration.
The TGD works on a simple premise and can be adapted for virtually any tidal gate. Technical specialist Chris Bainger from the Environment Agency was recently interviewed by the BBC about a site where a TGD was installed and he explains how it works succintly and clearly in this video:
https://www.facebook.com/bbcgloucestershire/videos/996170363765911/