Anglers can keep taking pictures of their trophy fish without worrying about harming them.
A new study from the University of Idaho found that briefly holding a fish out of water has no impact on its survival or reproductive ability.
The Idaho Department of Fish and Game requires anglers catch and release certain fish, rather than keeping them, to regulate population numbers. The study attempted to discover whether that practice — when it involves taking the fish out of water — is harmful to the animal.
Similar air exposure studies were recently done elsewhere, but they have “arguably not been sufficient,” said Michael Quist, one of the study’s authors and a UI associate professor of fisheries management.
For example, researchers tested laboratory fish, rather than wild fish, or air exposure was not consistent with how long anglers actually hold fish out of water.
The UI study attempted to replicate past studies but with conditions that mirrored how fish would be handled by anglers, Quist said.
Researchers from the UI and Idaho Department of Fish and Game, who published their findings in the North American Journal of Fisheries Management, studied 2,200 cutthroat trout, caught in a tributary of the South Fork of the Snake River, over two years.
Researchers chose trout because they are more sensitive than other species. If air exposure were to have an impact on fish, trout would be the most susceptible, Quist said.
Last spring, researchers tagged the trout with tracking devices, took genetic samples and simulated angling, while leaving some in the water and taking some out for 30 or 60 seconds (about the time anglers commonly hold their catch out of water). In the fall, researchers returned to the same area to find out how many fish survived.
They found that the fish briefly exposed to air were not impacted.
A study published last year by the researchers found more than 99 percent of anglers keep fish out of water for less than 60 seconds and the average was less than 20 seconds.
Quist said the study is important because it shows that fish and wildlife management agencies’ catch and release rules can allow anglers to take fish out of the water without causing harm.
Idaho doesn’t have rules that punish anglers from taking fish out of the water, but some states, such as Washington, fine anglers when they remove certain species from water, Quist said. And this study might stop fish and wildlife agencies from instituting such rules.
“This was a pretty big deal,” he said. “I think it’s one of the most comprehensive studies on air exposure on very sensitive fish. Fish are tougher than we give them credit for.”
“We don’t advocate holding fish out of water for longer than is absolutely necessary,” he added.