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Higher Steelhead Mortality Prompts Tangle Net Changes by Barry Espenson Columbia Basin Bulletin - February 7, 2003

After breaching federally prescribed limits last year, Oregon and Washington fishery officials are under the gun this year to keep impacts to steelhead mortality under a 2 percent cap during lower mainstem Columbia River commercial and sport fisheries targeting spring chinook salmon.

Last year's "tangle" net commercial was the first full fleet event to target spring chinook since the 1970s. A more limited commercial fishery was conducted in 2001.

Analysis by the multi-agency Technical Advisory Committee indicates the incidental mortality on winter steelhead during those February and March commercial fisheries a year ago likely ranged from 5.6 to 14.5 percent. The affected steelhead were the Upper Willamette and the winter portions of Lower Columbia and Middle Columbia stocks.

Officials from the states convene throughout the year as the Columbia River Compact, which sets mainstem commercial fishing seasons. A growing list of salmon and steelhead species is now listed under the federal Endangered Species Act, a fact the greatly complicates harvest allocation decisions.

The Compact on Thursday did approve a commercial fishery from Kelly Point at the Willamette River's confluence with the Columbia down to the mouth of the Columbia. The gill netters will be allowed to fish for 16 mostly daylight hours on Mondays, Wednesdays and Fridays during the weeks of Feb. 17 and Feb. 24.

The Compact's Steve King and Bill Tweit of the Oregon and Washington departments of fish and wildlife, respectively, also convened a joint sport hearing to extend the spring chinook fishery to as late as May 15. That mainstem sport fishery from the mouth upstream to McNary Dam (excluding the Bonneville pool) could be closed earlier if impact limits are reached.

An Interim Management Agreement covering upriver spring chinook, summer chinook and sockeye guides winter/spring mainstem fisheries is in effect through 2003. A NOAA Fisheries biological opinion and incidental take statement were issued related to the agreement to address allowable impacts to ESA listed fish -- including Snake River, Upper and Lower Columbia River and Upper Willamette spring chinook, Snake River sockeye and Snake River, upper Willamette, lower Columbia, and Middle Columbia wild steelhead and both wild and hatchery Upper Columbia steelhead.

The agreement and NOAA Fisheries documents allow a 2 percent non-Indian and 9 percent tribal impact on the upriver spring chinook. The spring chinook impact limit is split with .59 percent allotted to commercial fishers and 1.11 given to sport anglers. Three-tenths is reserved as a buffer to allow for a buffer below the impact limit and allow for special fisheries later in the season.

The 2 percent impact limit also applies to all of the wild steelhead, including the lower river winter run.

The information about steelhead mortality, contained in a Jan. 22 TAC report, caused NOAA Fisheries to reinitiate ESA Section 7 consultations with the state. NOAA Fisheries' Peter Dygert sent a letter to the states on Jan. 31 asking that they "provide greater assurance" that planned fisheries will not result in an overharvest of listed fish.

Dygert asked the states for a letter or report that describes:

• management actions that will be used to minimize steelhead encounters and mortality rates;
• specific limits on steelhead encounters, including how they were determined, and how they will be used in-season to keep the total harvest mortality within the 2 percent incidental mortality limit, and,
• the monitoring programs that will be used to track encounters in-season and regulate the fishery as necessary.

"Once received and reviewed by the NOAA Fisheries, the states' report will be incorporated into the proposed action of the revised biological opinion," Dygert wrote. "If the fishery is not conducted in accordance with the proposed action, the biological opinion is now applicable, and the incidental take statement would not provide an exemption from the ESA take prohibition."

"We believe the states need to be more specific about how the commercial fishery will be managed," Dygert said Thursday. He urged the Compact to take a cautious approach, limiting fisheries to stay well within the 2 percent limit and focusing on the needed research so that the effect of the nets on steelhead and other fish can be better evaluated.

Dygert told the Compact to learn what it can through careful monitoring and long-term mortality to "earn the trust of your critics." Sport fishing groups have, particularly been critical of the equipment employed during last year's experimental full fleet fishery. The nets deployed were predominantly 5 ½-inch mesh. That's smaller than traditional gill nets of 8-inch or larger mesh.

The intent with the smaller mesh is to entangle the fish, rather than trapping them by the gills as they push their heads through the larger nets. The commercial anglers were last year, and again this year, required to use "recovery box" with circulating water to revive unmarked fish -- steelhead and salmon -- so that they released be released. The fisheries during the past two years also required shorter "soak times" and drifts -- the time the nets are in the water and the length of the nets. Both measures reduce the amount of time the fish are trapped in the net.

The result of the 5½-inch experiment was that many of the steelhead, much smaller than the target salmon, were indeed gilled. Immediate mortality was about 2 percent of the hatchery and wild steelhead caught.

The states this year are taking a different approach. The commercial fisheries approved for later this month will employ 8-inch or larger mesh. The goal is to target the early returning Willamette River hatchery spring chinook, while allowing many of the steelhead to slip through the net and avoiding gilling those that are ensnared.

Cindy LeFleur of the Washington Department of Fish and Wildlife said Thursday that the commercial anglers are expected to net about 2,100 spring chinook during the six days of fishery. It is predicted that the fisheries would result in a .08 impact (out of .59 allowable) on the upriver chinook, but would eat up more than half -- 1.06 percent -- of non-Indian fishers allowable impact on listed winter steelhead. The state staffs have recommend that the commercial fisheries be allowed up to a 1.8 percent impact, essentially leaving a .2 percent buffer for sport fishing impacts (hooking mortality), and uncertainties.

Dygert suggested a buffer between the planned harvest and impact limit but didn't voice a number. Such a buffer was also proposed by another member of the federal family, Tim Roth of the U.S. Fish and Wildlife Service.

"A repeat of the unexpectedly high impact rate on listed steelhead in last year's fishery is unacceptable to the Service and I am sure to everyone else in this room," Roth said. The NOAA Fisheries BiOp outlines measures that agency deems necessary to avoid jeopardizing the survival of listed fish.

Roth did say that the work done by the state agency staff should avoid a repeat of last year's steelhead mortality by "adding additional gear restrictions to reduce impacts, by clearly defining preseason management threshold triggers and by committing to an intensive in-season monitoring and reporting system that will track and respond to cumulative impacts rates on a day by day basis."

The Compact has set a meeting for March 6 to discuss how future fisheries might be shaped. The states had planned at some point to shift to a 4¼-inch mesh net requirement. Those nets are expected to cause less damage to the steelhead and allow steelhead and unmarked salmon to be released relatively unharmed.

The idea is to catch as many of the Willamette fish early with the bigger mesh nets. The commercial anglers would be allowed a total catch of 17,500 Willamette hatchery spring chinook while keeping steelhead "handles" to a minimum. The impact limit on the Willamette run is 15 percent.

It is estimated that 85 percent of the Willamette fish will be marked with clip that identifies them as of hatchery origin. The upriver run is about 50 percent marked and is made up of mostly -- an estimated 76 percent -- age 4 fish.

The winter steelhead forecast for 2002 is 15,500 fish, about average but less than half of last year's 34,100 count. A 1.8 percent impact would be fewer than 300 fish.

The 4¼-inch nets are expected to entangle a higher percentage of the passing steelhead but leave them in a better condition to be released. The shift to the smaller mesh nets would be mark rate drops -- meaning more of the later arriving upriver fish are in the river and exposed to gill nets.

Based on 2001 and 2001 studies, TAC estimated that spring chinook mortality from encountering the 8-inch nets is 50 percent. The state staffs recommended that a 50-percent mortality rate also be used to calculate impacts on listed steelhead. Likewise they used information derived from 2002 spring chinook long-term mortality research using 4½-inch nets that suggested a 25 percent mortality rate. Again staff recommended that that 25 percent rate should be used to calculate steelhead mortality as well.

Commercial fishing interests testifying Thursday suggested that those mortality estimates were too high.

"We never heard of it before (Thursday), Gary Soderstrom, president of the Columbia River Fishermen's Protective Union, said of the 25 percent mortality rate. "We haven't seen any science behind it. I think it came out of the stars."

He suggested such decisions are "driven by politics instead of biology."

Others said that the mortality calculations are too low. Testimony by the Washington Chapter of Trout Unlimited's Jim Tuggle asked that the rate for 4¼-inch nets be boosted to 30 percent.

"Adopting a more conservative estimate to long-term steelhead survival will provide safeguards that were not present in last year's high steelhead mortality," Tuggle said. "The actual effect of a smaller mesh net as a tangle net is not yet known because last year fishers chose to use the 5 ½-inch mesh nets almost exclusively."

A preseason forecast pegs the overall 2003 spring chinook return at 271,000 adult fish to the mouth of the Columbia as compared to 432,300 last year. The upriver component -- those headed above Bonneville Dam is forecast to be 145,400 adults, about half of last year's return of 295,100 still an above average run for recent history. The Snake River "wild" or ESA listed component of the upriver run is expected to number 25,000, second highest in a data base that dates back to 1986. The record is last year's count of 60,200.

Last upriver run was the second highest run on record since 1938. The record was set in 2001 with a return of 416,500 upriver spring chinook. The upriver adult return was 178,000 in 2000, but counts during the 1990s ranged from a high of 114,000 to a low of only 10,200.

The Willamette River spring chinook forecast is for a return of 109,800 adults, down a bit from last year's 121,700-fish count but about average for recent history. The Willamette run is expected to be dominated -- 81 percent -- by age 5 fish.