Recreational Fishing May Affect Fish Species In The Long Term

By on June 5, 2015
UConn Ph.D. student Jan-Michael Hessenauer removes fish from the holding pen. (Credit: Jason Vokoun / UConn Photo)

Researchers at the University of Connecticut looking at the effects of catching and releasing on two different populations of largemouth bass have found that the fishing approach may affect the metabolism rates of fish caught, according to UConn Today.

Their results indicate that recreational fishing, which is largely viewed as harmless to fish, may have an impact on the long-term viability of fish species. That, scientists say, is because catch-and-release fishing appears to influence which types of fish become the fittest of their species.

“This scenario genetically favors the fish with lower metabolisms, the fish that are less likely to be caught by anglers,” said Jason Vokoun, associate professor of natural resources and the environment, in the blog post. “It suggests that we may be permanently changing exploited fish populations over the long term.”

The study is the first to identify the impacts of recreational fishing on wild fish using unfished populations as a basis. Scientists compared groups of largemouth bass from four lakes, two of which were open to catch-and-release fishing and another two undisturbed by fishing due to management by local water companies.

The investigation was simple. Scientists gathered baby fish from each lake and then moved them to a protected location with no fishermen or predators. The fish were tagged so that researchers could identify their origins, and then moved to pens to grow. Scientists compared the metabolic rates of the fish after a year had passed.

Hessenauer prepares to measure the volume of a fish. (Credit: Jason Vokoun / UConn Photo)

Hessenauer prepares to measure the volume of a fish. (Credit: Jason Vokoun / UConn Photo)

A significantly higher number of fish taken from lakes where recreational fishing was allowed had lower metabolic rates than those taken from the undisturbed lakes. The results, scientists say, point to a lessening in the kind of behavior that anglers prize – the aggressiveness with which many bass take bait.

“People affect the genetics of plant and animal populations just by the way we interact with them, and this study contributes to a body of knowledge that will help us truly understand how traditional management strategies may become less relevant over time,” said Robert Jacobs, fisheries biologist with the Connecticut Department of Energy and Environmental Protection, in the blog post. “The findings in this study may be a strong signal that we need to be much more creative in the ways we manage our inland fisheries.”

“Our results point to changes in fish populations, whether they are detrimental or not is really yet unknown, and probably depends a lot on a person’s point of view,” added Vokoun, in an email. “Interestingly, that the fish populations are changing in response to fishing could be considered a positive in that if they did not adapt, the populations may actually be in more long term trouble.”

The big message of the work, says Vokoun, is that fishing is an interactive system between fish populations and anglers with feedbacks and connections that are just now beginning to be understood and may extend to the very evolution of the populations being fished.

Up next for the investigators is to breed fish from the undisturbed lakes with those from the ones where recreational fishing is allowed. Scientists hope some of the offspring of those pairings will inherit the vigor and higher metabolisms of more wild fish.

Top image: UConn Ph.D. student Jan-Michael Hessenauer removes fish from the holding pen. (Credit: Jason Vokoun / UConn Photo)

About Daniel Kelly

Leave a Reply

Your email address will not be published. Required fields are marked *