Study finds fish with hook injuries struggle to eat after release

New research out of the University of California, Riverside, highlights a potential issue with catch-and-release fishing, a sport in which anglers catch a fish, but then release it back into the water without killing it. The act of removing the hook, researchers say, may have a serious impact on the fish's future ability to eat.

Catch-and-release fishing has long been viewed as a harmless sport, though issues about pain or harm to the fish have been raised throughout the years. The latest study on the topic found that injuries caused by hooks in a fish's mouth — specifically the removal of the hook — can reduce the creature's ability to catch the prey it eats.

The issue lies in how many popular fish eat — view suction feeding, which is the act of the fish quickly opening its mouth to suck in its food. The suction is created by negative pressure, which is impacted by the extra hole in the fish's mouth after the hook has been removed.

UCR researcher Tim Higham compared the injury's effect to that of drinking through a straw that has had a hole poked in the side. Proper suction is no longer possible, reducing what can be drawn into the mouth. Trout, bass, and salmon are among the fish that eat via suction feeding.

During the study, the researchers found that fish with hook injuries had "significantly reduced" feeding capabilities. This could result in the injured fish being more vulnerable to death due to an inability to get adequate food levels, but researchers caution that the long-term effects aren't clear at this point.