[6] Council Gets Schooled In Current Harvest Policies
A panel of independent scientists told the Northwest Power and Conservation Council last month that it can't really tell if the harvest of ESA-listed stocks is being adequately managed both in the ocean and inriver fisheries.
The panel said that current practice doesn't include tracking listed fish abundance levels, nor allow for major uncertainties in data and modeling efforts, which are likely to fail when ocean conditions change and productivity levels suddenly shift.
The scientists also implied that in the face of these uncertainties and a lack of clear objectives, it may not be enough to recover fish by simply reducing harvest rates by about 30 percent on such stocks as Snake fall chinook, as feds have done.
These conclusions came during a daylong presentation hosted by the Council on Columbia River harvest issues.
Canadian fisheries biologist Brian Riddell, a member of the Independent Scientific Advisory Board, told council members that only the most productive salmon runs could be harvested at rates around 60 percent. "Salmon are not a highly fecund fish," Riddell said. "They go through hundreds of fisheries."
Ocean harvest is now regulated according to fish abundance, he said, rather than managed for a ceiling. But with ocean exploitation rates of Columbia River fall chinook, including the listed Snake component, at about 45 percent, and inriver harvest rates in the 30-percent range, Riddell and fellow panel member Gary Morishima said there is enough uncertainty about mortalities throughout salmon life stages that the margin for error is small. Models have limited data upon which to base harvest estimates, they said, which further complicates the issue.
And now that many hatchery fish are marked by a clipped fin, like fish sporting a coded wire tag, the whole database developed by the tag technology to track catches in mixed stock fisheries is less robust than before, said Morishima. That's because the clipped hatchery fish sustain a higher harvest rate. Many sport fisheries allow only chinook with clipped fins to be kept, in order to let more wild fish spawn.
The historical record of fish survival data is "not stable," the panel said, because ocean conditions are highly variable. Fish numbers can vary "a hundred-fold" from one brood-year to another. The upshot is that large errors in predicting run sizes can occur if environmental conditions have changed and harvest models have not.
The panel said it is impressed with the management processes that have been developed and the effort to expand the scientific basis for salmon recovery efforts. But in a newly released report they say "they remain, however, concerned about the conservation of naturally produced salmonids and the relative affect of harvest on their conservation." The report was requested by the Council, the Columbia River Inter-Tribal Fish Commission and NMFS.
The panel looked at harvest levels of several stocks, including the Hanford Reach upriver brights, trying to answer a question posed by the report sponsors, who asked if current harvest management does an adequate job of managing and protecting ESA-listed stocks.
The scientists said this question can't be answered until real recovery objectives are established and essential components of each listed ESU are pinned down.
Federal policy has cut harvest levels about 30 percent from earlier levels, but without clear goals in mind for returning listed fish, there is no way of knowing if harvest levels are too high. Canadian Riddell said reducing harvest levels could significantly reduce the levels of risk to listed runs like the Snake River fall chinook, which are caught at the same time as the healthy Hanford run.
The science panel presented a series of recommendations, and called for a core set of data that monitors abundance and trends over time. The effort should include documented assessments that can be peer-reviewed, and more recognition for the uncertainty in their data and processes, along with a renewed call for adaptive management to salmon recovery.
The Council was also told that most of the Canadian fishery catches in the 2003-2004 season were U.S. salmon. This finding was reported during a discussion, by regional managers who co-chair the chinook technical committee of the Pacific Salmon Commission, of how harvest rates are set for ocean fisheries in Alaska, B.C. and offshore Washington.
Using in-season DNA testing, a cutting edge management tool used by Canadians to determine the stock composition of their commercial troll fishery off Vancouver Island, the results for the 2003-04 season showed that the Canadian fishery catch was about 88 percent U.S. salmon. About half of that was made up of fall chinook stocks from the lower Columbia, while another 19 percent were bound for Puget Sound.
The Snake fall chinook made up about 1.5 percent of the Vancouver Island catch, or 2,500 individuals, but that's about 21 percent of the number of Snake falls that made it over Lower Granite Dam by the end of 2003.
An independent economics panel summarized the value of Columbia River fisheries to the Northwest. Depending on the amount of fish produced by hatcheries, the economists pegged the value between $40 million and $142 million annually. They estimated the value of a spring chinook caught in the early gillnet fishery at $108 per fish and a fall chinook caught by a recreational fisher during the summer at $90 per fish. They said commercial fisheries accounted for nearly 60 percent of the high-end value of $142 million. Although a small part of the regional economy, they noted that it was very important to some local communities.
Public comment on the presentations found most commenters supporting cuts in harvest rates. The Independent Scientific Advisory Board got kudos from Native Fish Society director Bill Bakke for raising the issue of escapement goals for listed fish.
Providing some perspective, Portland attorney James Buchal reminded the Council that in 2001, a NMFS panel of nationally known scientists interviewed harvest managers for several days but couldn't figure out how the managers justified their harvest rates because their decisions didn't make "scientific common sense." -B. R.
The following links were mentioned in this story:
Report on Harvest Management of Columbia Basin Salmon and Steelhead
Economic Effects from Columbia River Basin Anadromous Salmonid Fish Production
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