Editor's note: this is the sixth story in the Morris Communications series "The case for conserving the Kenai king salmon."
Questions remain about king counts 121113 OUTDOORS 1 Morris News Service-Alaska/Peninsula Clarion Editor's note: this is the sixth story in the Morris Communications series "The case for conserving the Kenai king salmon."

Peninsula Clarion File Photo

Drift boat fishers pass the sonar station at it's location just upstream from the Sterling Highway bridge on the Kasilof River.

Photo By Rashah Mcchesney | Peninsula Clarion


Peninsula Clarion File Photo

Alaska Department of Fish and Game fisheries biologist Larry Wheat counts red salmon recorded by a DIDSON camera from a perch inside a small cabin alongside the Kasilof River on Tuesday morning. The department is using the sonar to keep track of escapement goals.

Photo By Rashah Mcchesney | Peninsula Clarion

Research biologist Jim Miller chats with a group about the Alaska Department of Fish and Game's sonar projects on the Kenai River on Aug. 15 in Kenai. Several in the group had questions about the accuracy of the department's chinook salmon measuring programs on the Kenai River.

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Wednesday, December 11, 2013

Story last updated at 12/11/2013 - 3:08 pm

Questions remain about king counts





In the postseason analysis, ADFG revised its estimates upward to show more than 25,000 king salmon having made it into the river. That was greater than the minimum escapement goal of 17,800, and shouldn't have led to the complete closures ordered by the department that led to an economic disaster being declared by the U.S. Secretary of Commerce.


Developing the sonar program





Split beam sonar has since given way to the dual frequency identification sonar, or DIDSON, which gives managers an actual image -much like an ultrasound - and allows for a better estimation of fish size to differentiate between species. The newest sonar iteration, the ARIS, or Adaptive Resolution Imaging Sonar, imaging technology, provides higher resolution and more easily trackable images of each fish.


"It has been so interesting," Burwen wrote in an email. "This is because we were always able to test and then use the newest acoustic technologies as they were made commercially available."



"As the tide came up and went down we would roll the sonar out on this railroad track, it was mounted on a cart. We tried to make the car go up and down with the tide, that was just an incredible ordeal because debris was always getting on the track," Burwen said. "Finally, we realized that you just couldn't do that."

That was the year, Burwen said, managers discovered why they weren't seeing any fish.

"The fish are bottom oriented at least much of the time and even one degree off, you'd lose all of your fish," she said.


Still, the technology has its drawbacks.

One of the primary barriers to a wider use of sonar to assess salmon runs -just 16 rivers in Alaska were using the program by 2013- is the difficulty in discriminating between fish species, according to a 2007 ADFG study evaluating the use of sonar.


Burwen said most managers in Alaska were using the DIDSON for inriver counting, but in large rivers like the Yukon where the range of river that must be viewed exceeds the DIDSON's range, split-sonar is still used.

Lower River


There, managers sit in a tent on the north bank of the river, where the riverbed was even enough that managers could ensonify - or see - the middle portion of the river.

Being able to see that portion of the river was crucial because according to ADFG data king salmon - though they can be found in all portions of the water column - tend to swim upstream in the deeper portions of the river.



"Every hour there's 80 minutes of data that we have to go through," he said.

The data is complex.

"It's hard to get through if you don't have experienced people on it," Key said. "As long as somebody is looking over their shoulders you can have untrained people doing it, but it takes some time."


"Everyone's double-checking their kings," Key said.




"The ones that we caught in our netting were generally quite a bit smaller and younger than the ones we caught offshore," said Tim McKinley, biologist and research supervisor for the Division of Sport Fish Soldotna area office.


Upper River research

Managers seeking to differentiate between it and the lower river site currently used for in-season management have dubbed the ADFG upriver sonar site at mile 13.7 as a "research project".



During the 2013 season - the first during which the upriver sonar array system was run for the entirety of the season - analysts waited until August to process data.





"It can be very time consuming, but is necessary to do, especially with a brand new technology like the ARIS," she wrote in an email.




"They're just numbers," he said. "Just because you get a larger number here doesn't mean it's not the same number, they're just different systems."

Despite repeated requests - both by the media and members of the public -for 2013 data from the upper river research site, a final estimate of king salmon passage has not been released.



"I think we've pretty much done as much postseason scrutiny of the numbers as we're going to and there were some surprises in there, but for the most part it kind of makes sense," he said.


"The thing is, that whenever you do something new - and especially when you have a tool that you have a lot of confidence in - sometimes you learn things that you didn't expect and so it's been very interesting," he said. "It's one thing to plan a new project at a different place on the river and work out all the logistical details of being able to count all the fish or virtually all the fish, but it's another thing entirely to get the data back and then really try to understand all the processes. You always get something unexpected."


"We need more thorough vetting of the data and the trends and what they may mean," Hasbrouck said.


Those meetings are with "higher ups," he said, not the biologists and fisheries scientists who had already interpreted the data - he added that needing to run the data through higher-level ADFG management did not mean there were politics factoring into the how the department interpreted the new data.


"It's not like this means that the interpretation is going to change," Hasbrouck said. "There are just other people that are part of the discussion."

The drawbacks


Between the two DIDSONs and the five ARIS units at the upriver site on the Kenai River, about 250 gigabytes of data were generated each day. That adds up to about 24, 576 gigabytes - or nearly 25 terabytes - of data collected in 2013.

"Data and file management is a big part of our project development," Burwen wrote in an email. "I'm happy to say we have the data flow worked out at both sites and both projects operate very smoothly with respect to data management."




"We had an expert crew and it was very dicey, they had to be ready. When a net hangs up on a boulder it's a lot different than when it hangs up downstream, you can't be hung up in a fast current on something that's stationary that's attached to your stern," Burwen said. "Evaluating safety is one thing that goes into it."


McKinley, the Soldotna area research supervisor, said the net apportioned estimate was an important tool for managers for the information it generated about the return per spawner for a specific year - or how many fish made it back into the river from a parent generation.

"That is, by and large, how we set our escapement goals," McKinley said. "This number of fish (spawners) produced this many (returners)."


"We really feel this upper site is going to work," he said.

In an earlier interview, McKinley said the net-apportionment would probably be phased out, however in a later interview he said ADFG would "probably continue our netting at about the same location, but be doing it differently."


Tarbox - who worked closely with the sonar on the Kenai River used to count sockeye salmon - said there was a nearly 20-year lag between when ADFG started using sonar technology in the Cook Inlet and when it became a management tool for king salmon.

"So, from 1985 to the present the focus has been on developing a technique to count chinook, " Tarbox said. "The managers (are) still looking for those magic numbers that they have confidence in and are reliable ... the drive to get reliable counts has been driving the research dollars."


"If you don't focus also on habitat issues and life history information, when you get a downturn in production, you're sitting there not knowing what's happening," Tarbox said.

Confidence in the data








Dwight Kramer, private angler and head of the Kenai Area Fisherman's Coalition, wrote in an email that he was also concerned that the department would rely on the sonar for in-season management without determining what effect downstream harvest could have on the run.

"It would seem to me that they would have to be very conservative until they have the numbers to liberalize the fishery otherwise they will risk over-exploiting the run and not enumerating enough spawners," he wrote. "I am anxious to hear their plan for this dilemma."

Looking ahead



"We'll be directly estimating what's there instead of using inferences to estimate what is behind the sonar," he said. "I'm absolutely looking forward to it."


"The idea is that since the water is moving so fast the fish stay closer to the bottom," he said. "We've got a few days scheduled for next year to see if there are more higher in the water column."


"If they compared well, it just wouldn't be cost effective to keep running both," he said.


Key said the increased openness was encouraging.

"I certainly wouldn't mind a little more community outreach," Key said. "I've been on the other side of that as a fisherman and it's the same kind of deal, it's just really what people want is more communication."

