What Kind of Fish Is This? The Answer Helps Measure Stream Health

Nate Schlater identifies fish on the bank of Eightmile Creek outside Marietta, OH.

Nate Schlater is sitting beside Eightmile Creek, sorting through a net full of fish that were just scooped from a live well.

He pulls out a writhing silvery minnow and turns it belly-up.

“See that mark on the underside of its jaw?” he asks. “It looks like a horseshoe. This is a stoneroller.” With that, he puts it into a bin teeming with other central stonerollers. In all, we find 512 stonerollers in this 150 meter stretch of Eightmile Creek, not to mention 588 other fish representing 16 species that also were captured.

While Schlater makes it look easy, identifying fish is tricky. It requires both book knowledge of the various species and hands-on experience. Schlater, Rural Action’s Monday Creek watershed coordinator, has a lot of both. This morning, he and Water Quality Specialist Tim Ferrell are working on EPA certifications that will attest to their knowledge.

Tim Ferrell, Ricky Vandegrift, and Nate Schlater use electrofishing to net fish in the roots of a sycamore along Goss Fork north of Marietta, OH.

When a stream is affected by acid mine drainage or other pollution, the number of species drops precipitously. As streams recover, more species begin to appear. That’s why it’s important for Rural Action’s watershed experts to be able to identify various species to track their growth or decline.

To do this, they use a process called electrofishing. Schlater, Ferrell, and AmeriCorps volunteer Ricky Vandegrift met in Amesville early in the morning for the hour ride over to Eightmile Creek, which is about eight miles east of Marietta.

The floating live well in the foreground helps ensure fish stay healthy during the sampling.

Schlater’s truck is packed to the gills with the gadgets needed for electrofishing, including the Roller Beast, which fills the truck bed, and a large blue live well strapped atop of the truck cap. The Roller Beast is basically a generator mounted on a pair of lawn rollers, which make it easy to move despite its heft. As an added bonus, the rollers float, so the entire rig can be rolled into the stream. But they didn’t need to do that today.

Once they arrive at Eightmile Creek, they begin unloading the equipment to prepare for electrofishing. The generator on Roller Beast provides a pulsed DC current, which flows through a 150 meter cable to a net on a long pole. When the net is placed in the creek, the charge stuns the fish, which can then be scooped up. The DC current doesn’t damage the muscle tissue of the fish, which means they can be released after the sampling.

From left, Ferrell, Vandegrift, and Schlater use electrofishing to sample fish from Eightmile Creek.

Schlater, Ferrell, and Vandegrift — protected from the mild DC charge by their waders — slosh slowly through the stream with one person using the charged net to shock the fish and the other two scooping them up and transferring them to the floating live well. The hum of the generator and passing traffic mix with burbling creek sounds as they work.

After they’ve covered 150 meters of creek, they fill a dozen or so plastic tubs with water and begin pulling fish out of the live well and sorting them based on species. It’s a tedious process that requires expert fish identification skills. Sometimes they pause to confer when a fish is proving tough to ID.

Fish are placed in plastic bins based on species.

Once all of the fish have been divided up by species, a detailed inventory is created, a few specimens of each species are preserved, and the rest are released back into the creek. Then it’s off to the next sampling site: Goss Fork, about 9 miles north of Eightmile Creek.

In a 150-meter section of Goss Fork, they find 19 species — a total of 938 fish, including several green sunfish, smallmouth bass and rock bass.

A rainbow darter that was found in Eightmile Creek.

Both Goss Fork and Eightmile Creek are in good health. The main goal of today’s work has been for Schlater and Ferrell to earn EPA certification. But throughout the year, they use this knowledge to identify struggling streams and track their progress as they recover. It’s a critical part of Rural Action’s work improving local watersheds.

For more information about the watershed program at Rural Action, contact Nate Schlater.

On October 11th, 2019, posted in: Latest News by