Fish Stories

Don’t be alarmed if you catch a smallmouth bass in the Susquehanna or its tributaries with a wire trailing from its underside. The animal is a participant in a study of fish movement related to wider research on the causes of fish diseases in the river system.

Release the fish unharmed and don’t tamper with or cut the wire, urges Penn State graduate student Megan Kepler. She pointed out that it’s an antenna from a radio transmitter that allows for the fish to be tracked with telemetry technology. The “Lotek radio-sensor tags” not only allow identification of the fish but also log the water temperatures that the fish is living in.

A doctoral candidate in the University’s intercollege graduate degree program in ecology, Kepler surgically implanted 40 of the $300 devices in smallmouth bass this spring and plans to insert them in 45 more later this year. They will allow her to track the movement patterns and habitat use of the fish.

“Since the early 2000s, smallmouth bass throughout the Susquehanna River and many of its tributaries have exhibited characteristics of disease, including lesions, black spots, and deformities,” she said. “Management agencies have been trying to determine why this is happening by assessing the bass population, conducting fish health surveys, studying parasites, and measuring many water-quality variables—such as temperature, dissolved-oxygen levels, pH, and contaminants.”

A primary goal of the research is to identify if and when fish are moving in and out of the tributaries, and to determine how this movement might relate to various environmental conditions, such as water temperature, and to key fish-life events, such as spawning. Kepler said, “Understanding movement and life-history characteristics of smallmouth bass has implications for both disease and fish management.”

—Jeff Mulhollem