AITKIN — A Minnesota agency is monitoring the quality of the state’s waterways by capturing fish using low voltage shocks.

The different types of fish the Minnesota Pollution Control Agency team will catch through electrofishing can tell them about a river’s quality.

“In general, fish and like aquatic insects are really good indicators of water quality, and you can really get an idea of the stream by looking at the species you find,” said environmental specialist Chad Anderson.

For example, longnose dace are sensitive to disturbance and pollution so finding them in a river is a good sign, said biologist Nate Sather.

The crew uses yellow poles that send a low voltage charge into the water. It momentarily stuns the fish and allows them to be captured easily using nets.

“We’re not harming the fish, and we’re getting a good representation of everything that’s swimming in this river,” Anderson said.

The fish are returned to the river after the team takes their measurements.

If the agency finds problems with the water quality, it will work to seek solutions. If the water quality is good, the agency will work to protect it.

“I feel fortunate to be able to help protect the water quality that we have in Minnesota,” Anderson said.

The five-person team is part of a statewide, 10-year cycle of reviewing water quality in all 80 Minnesota watersheds.

Other crews will take water samples from various depths of several lakes to see if the water meets standards for recreational activities such as swimming and fishing.