In an effort to protect young salmon from predation, new fishing rules will allow anglers to double their catch of some warm-water predatory fish found in 77 lakes across Washington state.

Reducing the population of salmon-eating bass, catfish and walleye is one of many ideas promoted by the governor’s Southern Resident Orca Task Force, which considered various strategies for increasing the number of Chinook salmon. Declining numbers of Chinook — a primary prey of the endangered orcas — is considered a leading cause of the dwindling population of southern resident orcas.

Largemouth and smallmouth bass, channel catfish and walleye are not native to Washington state, having been brought to this region starting 200 years ago. But all eat young salmon, and that’s considered a problem.

Whether increased bag limits on the predatory fish will lead to a noticeable increase in salmon has been debated since last year, when the Legislature implemented task force recommendations by passing a new law requiring the Washington Fish and Wildlife Commission to address the issue. The one-paragraph section of House Bill 1579 (PDF 180 kb) calls for the commission to “liberalize bag limits for bass, walleye, and channel catfish in all anadromous waters of the state in order to reduce the predation risk to salmon smolts.” The new rules, adopted in December, went into effect this week.

The new fishing rules, in effect for 77 lakes (PDF 109 kb) change the number of fish that can be retained by sport fishers:

• Largemouth bass: Increase the daily limit from five to 10 fish, keeping only one fish over 17 inches. Release all fish from 12 to 17 inches.
• Smallmouth bass: Increase the daily limit from 10 to 15 fish, keeping only one fish over 14 inches.
• Channel catfish: Increase the daily limit from five to 10 fish with no size restriction.
• Walleye: Increase the daily limit from eight to 16 fish, keeping only one fish over 22 inches.

For rivers, streams and beaver ponds, all size restrictions and daily limits are eliminated for these four species of fish.

Other “housekeeping” rule changes can be found in a news release, which reflects the specific language in the “freshwater recreational gamefish rules” (PDF 1.1 mb).

Opposition to the changes was expressed by a sizable number of anglers, including groups of bass fishers who prefer to release the fish they catch, so that the fish can be caught again by others. Warm-water fishers don’t want to see their fishery destroyed in an effort to protect a small fraction of juvenile salmon that might eventually make it to saltwater.

Hernandez Ruffin, president of the Washington State Bass Federation, pointed out that scientific support for the changes has been lacking. In testimony before the Fish and Wildlife Commission, he questioned whether removing warm-water fish will have any real effect on the salmon population. Other predators, from seals to birds, are just as likely to eat the juvenile salmon that survive, he said.

Also, he noted, it is well known that smallmouth bass consume northern pikeminnows (commonly known as squawfish), a major predator of salmon. Removing the bass will boost the population of pikeminnows, which will then have a negative effect on the salmon.

Several members of the Fish and Wildlife Commission said the arguments in support of the warm-water sport fishery convinced them that a balance was needed. An original proposal to eliminate all limits on 144 lakes was reined in as a result.

The 77 lakes are those that contain salmon, whereas the original proposal would have applied to non-salmon lakes as well. On the other hand, a proposal to limit the change to 14 lakes containing Chinook salmon was rejected as not conforming to the legislative directive.

Commissioner Don McIsaac said the commission is bound by the legislation to address all lakes that contain salmon in a meaningful way.

“I would like to send a message to those people who are very very concerned about orca that we do care about salmon protection for the purpose of enhancing orca prey,” McIsaac said during the December meeting. “Our action here has done something reasonable, but what we’re looking at is … such a small part of the whole thing that a large benefit to orca … is not very likely.”

Steve Caromile, manager of the warmwater fish program for the Washington Department of Fish and Wildlife, said data on fish populations in lakes is fairly limited, but the removal of catch limits on large Columbia River reservoirs so far seems to have had no appreciable effect on the number or size of fish caught in fishing derbies.

The result could be different for the latest rule changes, he said, because it may be easier to affect smaller fish populations in the 77 listed lakes — which are generally smaller.

“You can say that it is known that these (warm-water) fish all consume salmon as part of their diet,” Steve told me. “You can make the leap to say that there could possibly be an increase in juvenile salmon survival with these rule changes. Whether that would be a measurable effect is hard to say.”

No specific studies have been implemented to determine the effects of the new rule changes, but Steve said he would try to find a way to measure changes in fish populations in at least some lakes.

“Bass are fairly long-lived,” he noted. “To really see a change in the fish community, it is going to take at least six or seven years.”

Increasing the catch limits for bass and other warm-water fish is just a small step, Steve noted, but everyone recognizes that increasing the Chinook salmon population — and helping the orcas survive — may require many small steps.