[1] Basin Sockeye Keep On Coming Home
Sockeye are returning to the Columbia River in numbers not seen since the 1950s, helped by a multi-national effort that planted more than a million juvenile fish in Canada's Osoyoos Lake that feeds into the Okanagan River.
Sockeye counts at Bonneville Dam are about three times what Columbia Basin harvest managers had originally expected. By July 21, more than 213,000 had been counted, four times the 10-year average and higher than any year since 1959.
Most are headed for Canada, past nine mainstem dams, up eastern Washington's Okanogan (as it is spelled on the U.S. side of the border) River and over the border into Osoyoos Lake. Already, more than 187,000 sockeye are heading up the upper Columbia past Priest Rapids Dam.
By July 15, 137,000 sockeye had been counted passing Wells Dam, the last barrier before the Canadian-bound sockeye head for the Okanogan (no counts have been posted since), with more than 12,000 counted daily on July 6 and 7. However, warming waters may kill 50 percent or more of them before they reach Canada.
Some sockeye have been harvested in lower-river fisheries during the summer chinook season. Basin harvest managers estimated total sockeye mortalities from non-Indian recreational and commercial fishers at 1,000 fish, which is nearly half of their 1-percent ESA impact limit. Tribal treaty fisheries were projected to reach a total mortality of 9,400 sockeye through July 10, with another 6,700 available for harvest.
Sockeye returns to the region have bounced up and down with real vigor. In 1994, only 1,666 were counted at Wells. In 2001, about 75,000 made it to the dam, but in the following year only 11,000.
In 2004, numbers rose to 78,000, but have declined since. Last year, about 33,000 sockeye passed Wells.
About 25 percent of the Columbia run is expected to be headed for Lake Wenatchee. By July 21, about 33,000 were headed for the lake, where a Chelan PUD-funded hatchery program is based.
The sockeye returns to Canadian waters have been boosted by a new program that planted more than a million hatchery-raised fry in Skaha Lake above Lake Osoyoos.
BPA, along with the Colville Tribes, and the Okanagan Nation Alliance Fisheries Department, helped fund a three-year project to evaluate the feasibility of the project. Since then, Douglas, Chelan and Grant PUDs have helped fund the on-the-ground effort.
Kim Hyatt, a biologist with Canada's Department of Fisheries and Oceans' Pacific Biological Station in Nanaimo, said he was pleased with this year's return to Lake Osoyoos, noting that about 10 percent of the fry introduced into Skaha Lake in 2005 survived to the smolt stage--144,000--and provided a welcome addition to the one million wild sockeye smolts that migrated from the watershed in 2006.
Hyatt said wild sockeye production has also been enhanced by improved management of the whole Okanagan Basin, where a new provincial-federal agreement has been in place for several years to improve water for fish spawning, while satisfying irrigation needs and flood-control issues.
"Flows are managed much better than in previous years," said Hyatt, who noted that before the new management regime was implemented, flows had been out of compliance about 75 percent of the time. The new regime uses a complicated computer model developed with funding from Douglas PUD.
There is more study under way to develop fish passage facilities so returning adult sockeye can pass a small irrigation dam, McIntyre Dam, and recolonize old spawning grounds. Currently, the Skaha fry are raised from eggs taken from returning adults trapped below the dam.
Hyatt said productivity of the lake environment has improved over the past several years. In 2008, about 468,000 smolts were estimated to have been produced from the reintroduction project. With ocean conditions in prime shape, he expects even larger returns in 2010.
Even the tiny, ESA-listed component of the run that heads up the Snake River and aims for Idaho's Redfish Lake is showing signs of life. More than 800 of these ESA-listed cousins to "Lonesome Larry," the single spawner that returned to Redfish Lake in 1992, have been counted at Lower Granite Dam, the halfway point on their journey to the high-altitude spawning grounds.
Increased numbers of juvenile releases in 2006 from a captive broodstock program are likely playing a large role in the good adult show.
A first-hand report from NMFS personnel at the dam says the sockeye checked at the adult trap look very healthy, with no signs of infection common when water temperatures are high. NMFS' Jerry Harmon, who supervises adult trap operations there, said his crew estimated about 25 percent of the sockeye return is made up of jacks, which have spent only one year in the ocean.
The cool water and good flows still evident in the lower Snake should help this year's migration in their last 450-mile push to the Stanley Basin. As rivers warm, it's not unusual if only 25 percent or less of the fish counted at the dam make it all the way to Redfish Lake.
Last year, 52 fish were counted at Granite, but only four finished the last 450-mile trek to the trap at IDFG's Sawtooth Hatchery, near Redfish Lake. Managers had originally expected 50 to 100 to return.
In 2006, three sockeye returned to Redfish Lake. The average return over the past five years has been only 12 fish, but in 2000, when river conditions were relatively good, more than 200 of them made it all the way home, about two-thirds of the number counted at the dam that year.
The Fish Passage Center released a July 14 memo that strongly suggested the high sockeye returns to both the Columbia and Snake were mainly due to court-ordered spill at federal dams and high flows when juveniles migrated in 2006, while others have attributed the blockbuster runs more to improved ocean conditions. NOAA Fisheries is reviewing the FPC memo, which used pretty weak correlations (r2 = .34) in their analysis. This means that only 34 percent of the variability in adult returns in their analysis could be explained by the factors they considered.
Most scientists say an r2 of .65 to .7 is necessary before a correlation is taken seriously enough to be used in management considerations.
Sparks may fly. In the recent past, NOAA Fisheries scientists have found little to no relationship between inriver juvenile survivals and smolt-to adult returns, but a strong correlation between ocean conditions and adult returns (see NW Fishletter 236) .
The FPC fired off another memo a few days later that did seem to backtrack a little, by acknowledging the importance of ocean conditions for adult returns. But the memo also noted that that last high sockeye return to the Snake in recent years happened in 2000, when 299 were counted at Lower Granite. The FPC said their analysis showed that the 1998 outmigration that made up most of the 2000 return experienced the lowest water travel time and second highest average spill percent among the years they analyzed with good ocean conditions.
What the FPC didn't say was that the captive broodstock program really took off in 1998. According to the FPC's annual report, nearly 336,000 sockeye smolts were released into the Snake zone in 1998. In 1997, only 1,926 were released, a year when flows in the basin were extremely high. Only 14 sockeye returned to the dam in 1999.
The FPC's July 14 memo may also be reviewed by the Independent Scientific Review Board, the group that weighs in on various issues in the salmon recovery arena. NPCC staffer Erik Merrill told NW Fishletter by e-mail that the FPC had sent the ISAB a copy of their sockeye memo "to inform the ISAB's spill-transport review, so the FPC didn't request a review on their own analysis as much as offer the analysis for background material. The ISAB was interested in information on other species besides steelhead and chinook that are affected by transport and spill operations, particularly sockeye and lamprey." Merrill said the Council has also expressed interest in having the ISAB review the memo, but hasn't yet issued a formal request.
"In any event," said Merrill, "the ISAB is going to review the sockeye analysis and discuss how it informs the spill-transport review, with the intent to also anticipate potential Council questions on the FPC analysis itself."
Sockeye runs in BC are also coming in stronger than expected. Canadian fish managers have upgraded their estimate of the Early Summer-run sockeye on the Fraser River to 500,000 from 349,000. Their July 22 announcement also noted that this year's Summer-run sockeye run is tracking near their 50 percent probability forecast. Strong catches were reported in test fisheries in Juan de Fuca Strait.-Bill Rudolph
The following links were mentioned in this story:
Fish Passage Center, July 14, 2008
Fish Passage Center, July 21, 2008
NW Fishletter 236, Sept. 20, 2007
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