7 days ago
Electric boat used for fish surveys on River Thames
A unique boat is being used for important fish monitoring surveys along the River Thames.
The Environment Agency is carrying out the work between Iffley Lock in Oxford and Teddington Lock in London using a specialised boom boat.
The boat uses an electric field to temporarily immobilise fish, allowing officers to study the health of the river's fish population.
Jonathan Baxter, team leader at the Environment Agency, said: "We undertake annual fish monitoring on the Thames and its tributaries.
"We have a statutory duty to maintain, improve, and develop fisheries, and the Thames Trout makes what could be a tricky process an absolute doddle.
The boat used to catch the fish (Image: The Environment Agency)
"Surveys such as these provide extremely accurate data from our principal fisheries and can detect trends linked to factors such as climate change."
Surveys are typically conducted at dusk when the river is quieter and fish rise closer to the surface, improving capture rates.
The Thames Trout boom boat is equipped with the largest front-mounted underwater electrodes in the Environment Agency's fleet.
These electrodes cover a wide area of the river, making the process more efficient.
The electric field stimulates the fish's nervous system, causing them to swim towards the operator or leaving it unable to swim away.
They are then netted and placed in aerated holding tanks to recover before being identified, measured, and released.
A sea trout caught during the survey (Image: The Environment Agency)
Mr Baxter said this year's warm weather seems not to have had an impact on fish populations.
He said: 'Over 6,200 fish were caught in the 2024 survey between Iffley and Benson, with results showing an abundance of healthy fish.
"We've surveyed over 10,000 this year and despite the recent dry weather, we have seen no significant impact to the Thames fish population, although as with any dry weather event, anglers should be mindful of the fish they are catching as some species may need a longer recovery period in extreme heat.'
The fish populations in the River Thames provide an opportunity for people of all ages to get out and enjoy fishing on one of our country's largest rivers.
Anyone aged 13 or older needs a licence to fish for salmon, trout, eels, or freshwater species.
Information on when a licence is needed and how to buy one is available online on the UK Government website.
Licences can also be bought by calling 0344 800 5386.
The income from rod licences helps with the sustainable management of fisheries.
The Environment Agency's fisheries enforcement officers check private lakes, rivers, ponds, and canals for illegal fishing, supported by clubs, the Angling Trust, and the police.
