By Lee Leschper
Biologists on the Nushagak River are in the second year of key research on how well king salmon survive being caught and released by sport fishermen.
The Alaska Department of Fish and Game mortality study is intended to give managers and anglers statewide a better idea of the impact of catching and releasing king salmon on traditional fishing tackle.
There has long been debate about how well fish, especially big game fish like king salmon, survive after being landed by a fishermen.
Lee Borden, an ADF&G biologist in Dillingham leading the study, says it is mimicking the efforts of sport anglers as closely as possible.
“We are fishing like guides,” Borden said. “We are duplicating what fishermen do, except perhaps that we use a hinged cradle instead of a net so we can control them, and use a PVC applicator to tag the fish, behind the esophagus.
“The tag doesn’t affect their feeding since they are not feeding in the river.”
Borden logs the location and condition of the salmon when released, including variables such as where it was hooked, if it was bleeding when hooked, and its overall body condition.
Borden tracks the tagged fish by small plane, flying low over the river with a receiver, which picks up and marks each fish’s location via GPS.
“We have a mortality signal. If a fish stays in one spot for four hours, it is marked as dead,” he said. “It’s been working well. We’ve had no equipment problems.”
The travel and durability of some of the fish in last summer’s study might surprise anglers.
“August 10 (in 2017) we found a fish tagged six weeks prior, and 100 miles upriver, that was still moving and presumably spawning,” Borden said.
ADF&G is not releasing results from the study until after it’s completed in 2018, Borden said, but the results so far are encouraging. The kings handled and released carefully have shown a high probability of surviving to continue spawning.
The last time Alaska did a mortality study on kings – on the Kenai River in the early 1990s – more than 90 percent of the salmon survived. One study showed about 9 percent died of injuries related to being caught, while another study showed about 6 percent died.
Fish-handling techniques have improved dramatically in the past 25 years, too.
“In 2017, we put 107 tags out,” Borden said. “It was a low-water year. Our goal (for the entire study) is 350 tags.”
Borden expects that the study will not just identify mortality, but give fishermen guidance on how to improve the survival of the fish they catch.
“We should identify techniques and how handling the fishing affects mortality, for example, how long you fight a fish, limited use of landing nets and not removing the fish from the water,” he said.
In Alaska, if a fish is to be released, anglers are not allowed to remove it from the water.
“We can track back to individual fish, and look at the metrics of when and how it was caught, where and on what kind of gear,” Borden said.
Some assumptions may not be valid, he added.
“For example, one fish was bleeding released, yet traveled another 140 miles upriver,” Borde send. “More make it than we think.”
The most important rule to improve survival, Borden noted, is to not remove a caught salmon from the water at all.
“It definitely takes away the opportunity to damage the fish. A king taken out of the water is not going to be cooperating,” he said. “Trying to get a picture, dropping it in the bottom of a riveted boat, flopping, all does harm.”
Borden says there is an emerging fishing ethic and commitment to release fish safely.
“I noticed in my fishing that the angling culture has changed over the years, where the users are at the point of being concerned about the resource,” he said. “Most guides I see fishing generally treat these fish really well. They’re concerned about the resource.
“The angling culture has changed in the last decade or two where people care about the fish, and care about how they handle them.”
Editor’s Note:
Anglers on the Nushagak encountering tagged king salmon should not remove tags from fish they are releasing. Anglers harvesting tagged kings are asked to return the tag and provide information regarding the date, location of capture and condition of fish as soon as possible to the Dillingham ADF&G office: P.O. Box 230, Dillingham, AK, 99576. Anyone with further questions can contact Lee Borden, Assistant Area Management Biologist in Dillingham at 907- 842-2427.
Want to read more about Nushagak king salmon? See more of this story and a rundown on fishing the Nushagak in Alaskan Spirit Magazine, magazine of Ravn Alaska: https://www.flyravn.com/about-us/alaskanspirit/
