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NOAA Moves Forward on
Updating Stock Status Assessments

by Barry Espenson
Columbia Basin Bulletin - August 1, 2003

Strong upper Columbia River basin salmon and steelhead returns of recent years brighten stock status assessments, but it appears work remains to ensure they won't slide toward extinction, according to evolving analysis by NOAA Fisheries.

The federal agency is doing the re-analysis of individual populations and "evolutionarily significant units" sooner than it had anticipated, spurred by a court-ordered reworking of the agency's 10-year salmon strategy. The revisions to the 2000 Federal Columbia River Power System biological opinion are to be completed by June 2 of next year.

The BiOp judged that the survival eight of the 12 basin salmon and steelhead stocks listed under the Endangered Species Act are jeopardized by planned federal hydrosystem operations.

The BiOp's reasonable and prudent alternative, and an accompanying Basinwide Salmon Recovery Strategy, laid out a set of actions that the agency believed would, if implemented over a 10-year span, bring enough survival improvements to avoid jeopardy. Those improvements are envisioned within the hydrosystem itself and through off-site work such as habitat improvements and changes to hatchery and harvest strategies. U.S. District Court Judge James A. Redden, in a May opinion, declared the BiOp's RPA illegal.

"NOAA's reliance on federal range-wide, off-site mitigation actions that have not undergone section 7 consultation and non-federal range-wide, off-site mitigation actions which are not reasonably certain to occur was improper and, as to eight of the salmon ESUs, the no-jeopardy opinion in the RPA is arbitrary and capricious," Redden wrote. The agency is now launching its effort to rework the document to correct those deficiencies.

As a part of that process is a NOAA effort up update population growth rate estimates for the listed populations and reassess stock status. The BiOp analysis used to judge the peril posed to the listed stocks, and calculate the survival improvement needed to avoid jeopardizing their survival, used population data that ended in most cases in 1999.

The BiOp called for a full-scale jeopardy analysis, using updated data, to be completed for the so-called 2005 check-in. But Judge Redden forced the need both to correct the deficiencies he cited and produce in short order an assessment of whether the reworked strategy avoids jeopardy, according to Brian Brown, chief of NOAA's Northwest Region hydropower section.

Brown and NOAA's Chris Toole met Wednesday with regional fish and wildlife managers to explain the process and preview what Brown called "a work in progress and some pretty preliminary stuff."

He and Toole said that the updated analysis generally includes adult returns through 2001. The stock status analysis process is just getting under way, with "numbers changing every day," Toole said. The analysis will also be redone late in the fall when adult return data becomes available for 2002.

The analysis estimates preliminarily the population growth rates (lambda) -- some of which are positive (1 or above) and some of which are negative (less than one). The analysis will ultimately estimate how much survival improvement is necessary for particular stocks to reach a pair of thresholds. The BiOp survival standard said that there must be a 5 percent or less chance that a population will go extinct over the next 100 years. Recovery means that there is a 50 percent chance or better that a stock will achieve certain abundance levels within 48 years.

The analysis at this point only includes the seven listed upriver stocks that the 2000 BiOp said were in jeopardy of extinction. The analysis include individual population trends for three time periods of interest, but Wednesday's presentation to the Columbia Basin Fish and Wildlife Authority's Anadromous Fish Committee focused on one -- 1980 to the present.

The preliminary work compares the BiOp analysis from 1980 to, for the most part, 1999, with population trends from 1980 through 2001.

In most cases, the population growth rate improved with the addition of the most recent adult return data. Toole stressed that although the trend improved from the BiOp estimate, many of the individual populations still have spawning aggregations that are declining. Many others show growth, but perhaps not enough to eliminate the extinction risk or bring recovery.

Improved feeding condition in the ocean where the salmon and steelhead grow to maturity is credited in large part with a recent surge in the number of salmon and steelhead returning to the Columbia Basin.

Adult fall chinook salmon returns since 1980 have ranged from 214,900 to 871,000, but for the most part have been between 250,000 and 350,000. The exceptions are the period from 1986-1989 when a series of strong runs peaked at 871,000 adults in 1987, and the current era. The count jumped from 253,300 in 2000 to 548,900 in 2001 and 733,100 in 2002. The preseason forecast is for a return of 595,200 fall chinook this year.

For upriver steelhead, the trend is similar. Most returns since 1980 were in the 200,000 range, though strong returns numbering near or above 300,000 were evident in the mid- to late 1980s. More recently, the upriver return numbered 211,500 in 1999 and 282,400 in 2000. The upriver return exploded to 630,200 in 2001, the highest count on record (since 1938. That was followed by the second highest return, 478,000 in 2002. A return of 360,900 is expected this year.

The upriver spring chinook stocks were even more beleaguered, with only three returns of more than 100,000 fish since 1980, two of which were in the mid-1980s. The upriver run bottomed out with only 10,200 adults returning in 1995. But 2000 saw 178,400 return. Then 2001 witnessed a record 416,500 adult return. That was followed by the second largest return on record, 295,100 in 2002. The adult spring chinook return this year was 208,430.

The wild, listed portions of those steelhead and chinook runs generally improved over the same period. The extent of the improvement varied from population to population.

The seven ESUs for which stock status re-analysis is under way includes the Snake River steelhead, fall chinook and spring/summer chinook, Upper Columbia chinook and steelhead, Mid-Columbia steelhead and the Columbia River chum.

The preliminary work shows that recent population boosts "gives us from a small (zero) to a 5 or 10 percent change in lambda," Toole said. That reflects an improved population trend, but many still show negative population growth rates.

"In most cases the needed survival change (to meet survival and recovery standards) is less," with the inclusion of the newer adult return data, Toole said.

The time period population trends will be used to project that population's growth, or lack thereof, into the future.

Barry Espenson
NOAA Moves Forward on Updating Stock Status Assessments
Columbia Basin Bulletin, August 1, 2003

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