Electrofishing is a common method used to survey fish populations. A small electrical current is sent through the water which stuns the fish allowing them to be caught in a net. This shows us how many fish are in the stream and what species are present. Measuring and weighing the fish can tell us how old they are and what condition they are in.

Electrofishing doesn’t cause any harm to the fish, the effects only last about a minute. To ensure it is being done properly surveyors are trained and consent is required from the Environment Agency before a survey is performed.

Watch the video to see how it’s done…