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With new tools, biologists aim to avert another Kenai king disaster

Jenny NeymanRedoubt Reporter
Stephen Nowers photo

There was no lack of data, analysis, statistical models, facts, figures and hypotheses presented at the second meeting of the Upper Cook Inlet Task Force at the Challenger Learning Center of Alaska in Kenai.

But for the six hours of answers and information, the main question driving the creation and effort of the task force remains unanswered: If the 2013 Kenai River king and sockeye runs shape up like the 2012 returns, can another disastrous fishing season be avoided?

While nothing has been settled yet, an answer is closer. The Alaska Department of Fish and Game has already released its new late-run Kenai River king salmon escapement goal, recommending 15,000 to 30,000 fish be spared from hooks and nets to get upriver to spawn.

The report still is in a draft form, and it’s only an interim figure to be used until the goal comes up for review and revision before the Alaska Board of Fish in 2014. But it represents progress, especially in times of low abundance of kings, as has been the trend in recent years, said Robert Clark, chief fisheries scientist with the Alaska Department of Fish and Game, who gave a presentation on the updated escapement recommendation.

“We need to manage carefully because runs are going to be small in the near term — they just are, it’s a certainty. But this analysis is a breakthrough from our old assessment,” he said.

Better sonar technology

The new goal was developed using king count estimates generated with DIDSON sonar technology, seen among biologists as far more accurate than the previously used target-strength estimates produced by split-beam sonar technology. Split beam has been shown to confuse smaller kings with sockeyes, especially when both fish are mixed together in the river. The previous goal range of 17,500 to 35,000 fish was developed using the old sonar estimates. The department switched to using DIDSON technology exclusively at the king sonar site at river Mile 8.6 last year, but was still using the old escapement goal. Now a DIDSON-based escapement will be tracked with DIDSON sonar.

Keeping better count of the fish is only part of the battle. Managing them is the other.

“This 15,000 is our best guess that balances the risk of the fisheries — keeping fisheries viable and going — and balancing that against the risk to the stock in terms of overfishing,” Clark said.

That balancing act was particularly difficult under a perfect storm of factors contributing to the maelstrom that became the 2012 Kenai River fishing season. A low early run of Kenai kings in June and poor returns of kings elsewhere in the state raised a red flag that the Kenai late run of kings might also be troubled. Supporting that concern was the late arrival of the late king run. At the same time, a robust return of sockeyes streamed into the river while kings trickled in.

The result was restrictions in the sport and personal-use fisheries on retention of kings, then an all-out in-river closure on king fishing. That triggered a closure of the area’s commercial set-net fishery for sockeye, in order to prevent kings from getting caught in the commercial nets. When it became clear that kings were late more than nonexistent, management didn’t allow for creative solutions to address the unusual situation. Save for a few, mostly unproductive openings, the set-netters lost their season, sport fishermen lost much of their Kenai king fishing season and more sockeye than desired made it upriver, all to protect kings that ended up making escapement.

“The problem with last year really wasn’t abundance, it was how the run showed up, and a lot of it showed up late. In those situations, you try to do as a good a job as you can,” Clark said.

Hindsight not enough

Discussion of the science behind the escapement goal eventually turned to the larger goal of the task force, to consider ideas for preventing a repeat of last year’s fishing season.

“We can discuss how you count fish all day long. We could spend a whole week on that,” said Vince Webster, co-chair of the task force and a member of the Board of Fish, as he turned to Fish and Game managers with the 15,000-fish question: “With this new escapement-counting system, have you guys thought of how it’s going to affect how you’re going to manage next year? Can you tell us when you’re going to be concerned that your run is going to be late and might not make escapement and close the fishery down?”

Avoiding last year’s outcome isn’t simply a matter of applying hindsight. Even knowing what they know now, managers said they wouldn’t have done much differently.

“Based on what we didn’t know last year that we know now . . . we would have went through a similar situation where we would have restricted and eventually closed the sport fishery. (There could have been) differences in the number of days, in when restrictions occurred, but the run wasn’t large enough to support harvest in July,” said Begich, an area sportfish biologist.

'We need a better crystal ball'

But 2013 may not be a repeat of 2012. For one thing, no one yet knows what the runs will be. The Upper Cook Inlet sockeye forecast is again strong, but the king forecast isn’t available.

“We’d need a better crystal ball than we have now,” Vania said.

Though fishermen like to know what kind of year they’re getting into, fishery managers prefer not to make preseason decisions, because much depends on information arriving during the season.

The preseason forecast is one indication of how a run will shape up, but there are others that come later in the year — the strength of the early run of kings in June, king returns to other rivers in the state, and how many kings are showing up in Cook Inlet commercial fisheries.

“We have a lot of information that we can gather leading into June to help us decide what we’re going to do in July,” said Pat Shields, area management biologist for commercial fisheries.

But there are already a few concrete differences that could allow more fishing opportunity -- even if the run is on the low end, as expected.

“These runs are small right now. I can run numbers all I want but what’s coming back, you look at what we’re seeing in terms of productivity relative to the average ... productivity now is quite a bit lower,” Clark said.

What has increased is Fish and Game’s ability to count fish, with DIDSON sonar and the new escapement goal. Clark said the new technology means better accuracy, and also could help indicate run timing, as well as run strength. “We get better measurements of (fish) size (with DIDSON), and size translates into chinook salmon,” Clark said.

Fish and Game will continue other run-tracking measures, such as monitoring how many kings are caught in commercial sockeye nets, running a test net at the sonar site to cross reference the proportion of kings to sockeyes in the river to the sonar estimates, and surveying anglers to gauge how many kings they’re catching and how long it’s taking to hook one.

Together, the DIDSON sonar and other run indices are expected to provide better in-season information, which helps answer a concern among some fishermen.

“I think it would take away a lot of the risk of not hitting these king (escapement) goals if we knew more often where we were at,” said Robbie Williams, one of the task force members, a set-netter and president of the Kenai Peninsula Fishermen’s Association.

DIDSON sonar also will provide the ability to keep the sonar program running in August. The target-strength estimates from the old split-beam sonar became practically useless that late in the season, because of challenges in distinguishing kings from the silvers and pinks showing up in abundance.

Running sonar in August will be particularly helpful if the July king run again shows up late this year.

“When we get into the late part of the run, when pinks start showing up and kings are moving really slow and wallowing at the site, we lose the ability to count fish, really, with target strength-based sonar, at the current site,” Clark said. “Now that we have the DIDSON ... we should leave it in as long as we can and get better timing data later in August, because what we’ll have is the ability to stay in the water longer.”

But DIDSON isn’t a magic-bullet answer to all the difficulties in tracking escapement. At the current king sonar site, Mile 8.6 in the lower Kenai, water level is influenced by tides. When water is high, fish can pass behind the sonar transducers. Scientists are now aware of this, and factored an estimate of missed fish into the new escapement goal range. They also are working on moving the king sonar site upriver, out of tidal influence, and are going to compare data this season from the existing site with the new one at about mile 14.

“The way forward is what we need to focus on. The uncertainties are still there, yeah. (But) they’re not huge,” Clark said.

Even if this year’s Kenai salmon runs prove similar to last year’s, management of the fisheries still differ due to changes the task force may take to the Board of Fish. Three proposals under consideration stipulate that any changes would be on a trial basis for 2013.

“We made a commitment to put a sunset of one year on anything that would be put into regulation in the (Board of Fish) spring meeting as result of this task force. Whatever we do will have one-year sunset to see how it works, see what the department learns,” said Tom Kluberton, task force co-chair and member of the Board of Fish.

Jenny Neyman is editor of the Redoubt Reporter, covering news from the Kenai Peninsula. Used with permission. Find more Redoubt Reporter stories here.