Electrofishing on the Teign

A warm clear July morning saw Craig from the Westcountry Rivers Trust, Neil from the Teign Angling and Conservation Association and Geoff from the River Teign Restoration Project meet up at a farm on the Blackaton Brook at 7.30am, for a day of fish surveying and counting using a technique known as electrofishing (EF). The Blackaton Brook is an important tributary of the main River Teign.

After a chat with Michael whose land the brook flows through, we donned our waders, entered the water and started work, with Craig taking the lead.

EF is a technique which uses a mild electric shock to briefly stun fish within a metre of an electrode attached to a long insulated pole. The pole is held by Craig who is carrying a large backpack containing heavy duty batteries and a whole lot of electronic wizardry. The pack is connected to the pole and electrode and by pulling a trigger Craig fires off an electronic pulse. Within seconds two little fish rise to the surface in a dazed state. Neil is stood immediately downstream of Craig and the fish being visible easily nets them out and gently puts them in a bucket where they quickly recover. This carries on for a total of 5 minutes and then Craig and Neil exit the water and carefully identify the species and numbers of fish.

Craig measuring one of the salmon fry

This first location of the day reveals 15 baby salmon (fry), 10 trout fry, two trout and 4 bullheads (millers thumb) and after measuring the salmon and trout fry and the trout, all the fish are carefully returned to the area of the brook from whence they came, where they all swim away unharmed.

Geoff as the newcomer to this is the amazed onlooker throughout this exercise. Neil, who has been surveying the location for several years declares a good result as it means that at least one pair of adult salmon ascended far up the Teign catchment last winter to spawn and start the incredible lifecycle of the salmon over again. The trout fry are evidence of spawning by trout or sea trout.

Everything is recorded and equipment loaded into the truck and we travel downstream to our next location. Another good result. By the end of a long day, 8 locations along the river have been surveyed and records taken of all fish that ended up in the bucket.

After a second day of surveying, the team have a mixed set of results. Some locations are better than in previous years, others not so. One downstream location was better than ever, but two locations on a badly polluted tributary revealed no salmon fry and just a few trout fry. A few eels and loach were also recorded over the two days.

Brown trout of the Upper Teign

The team met again throughout the summer for a further 4 days of surveying. Colleagues in the Westcountry Rivers Trust will assess the results and help plan actions that can be taken to improve spawning success at poorer locations.

If you’d like to know more about these surveys, please contact Geoff Stephens – contact details are on the ‘Contact Us’ page.

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