[2] Science Panel's Spill/Transport Review Faces More Scrutiny

At the Oct. 2 IT meeting, NOAA Fisheries thanked the independent science panel for their recent report recommending changes to the feds' spring transport policy, but said it wasn't sold on the idea.

The panel called for maintaining a "spread-the-risk" policy that keeps spilling at dams while collecting fish for transport downstream. The feds plan to stop spilling for two weeks in May at dams where fish are collected, to give as many as possible a free ride past the dams.

Bruce Suzumoto, assistant regional administrator for NOAA Fisheries, characterized the difference between the ISAB recommendation and the feds' position as "trading uncertainty for real benefits."

Suzumoto, a surprise attendee at the Oct. 2 meeting of the Implementation Team, which is made up of mid-level policy managers, spoke after participants heard a presentation on the new ISAB report by its chair Rich Alldredge, a statistics professor from Washington State University.

His PowerPoint presentation was the same one he delivered two weeks earlier when he presented the panel's results to the Northwest Power and Conversation Council, based on months of examining the tradeoffs between using spill at dams to pass fish and transporting them past the hydro system.

The ISAB report (NW Fishletter 252) suggested that stopping spill might shortchange survival of ESA-listed sockeye and unlisted lamprey, even though they admitted they really had little to no data to support the notion.

The brand-new 2008 BiOp calls for ending all spill at collector dams for two weeks in May and barging as many fish as possible, to boost ESA-listed steelhead returns. It's a strategy supported by analysis from NOAA's COMPASS model to reach performance standards called for in the latest salmon plan.

At the IT meeting, Ritchie Graves, NOAA Fisheries' hydro branch chief, pointed out that the ISAB's analysis--which suggested overall fish survival increased as the percentage of spill went up--was complicated by a number of factors, including the finding that about 70 percent of juvenile steelhead tend to use surface passage routes regardless of the amount of water spilled at dams. He cautioned that this could be a "confounding factor."

But Alldredge said the ISAB still felt spill should be the default option for passage at dams. He said the panel was also concerned about evidence that showed barged fish had increased stray rates as adults. But that turned out to be more complicated as well.

Corps' of Engineers' biologist Rudd Turner said it was mostly hatchery fish that strayed, like Snake River steelhead wandering into the Deschutes.

NOAA Fisheries' researcher Bill Muir said some fish actually showed up in the right place after straying on their way home. "Some hatcheries are worse than others," he said.

Alldredge observed that the PIT-tag data used by NOAA and its COMPASS model may be short-changing inriver survival benefits, since there is a little information suggesting non-detected fish (that pass dams via spillway or turbines) return at higher rates. "The benefit of transportation may be inflated," he said.

In recent years, the feds have suggested another possibility--that the PIT-tagged results underestimate overall returns because the bypass systems select for smaller fish, which have overall lower survival.

But Alldredge raised another big question--what fish should we be using to measure survival? No one ventured to answer that one. The feds have already gone on record saying that trying to measure survival of truly undetected fish is not science, since it is impossible to accurately determine the number of undetected fish starting their journey through the hydro system.

Graves said the ISAB position assumed a differential effect of tagging, and Alldredge agreed such a line of questioning "opens the Pandora's Box of differential mortality."

But Graves said tagging wouldn't help answer questions about sockeye and lamprey survival, since at present, sockeye are too small to acoustically tag, and lamprey have the wrong body shape. With those constraints, he didn't see any way to get more survival data about them over the next three to five years.

The ISAB's report expressed concern that without spill, sockeye survival could go down significantly, because there was some evidence that they showed signs of significant descaling at bypass systems--which would be their only route past dams besides turbines if spill was ended

Graves pointed out that sockeye descaling rates have decreased at John Day and Bonneville dams in recent years, and there was some evidence that descaling seen at juvenile monitoring sites at dams may have actually occurred before the fish had entered the bypass systems.

Alldredge told the IT that the science panel's embrace of the spread-the-risk policy was more of a "philosophical concern" than a position based on data, though he did say juvenile survival results from 2006 and 2007 show some evidence that more spill "works."

The ISAB review also suggested that putting more fish in the river might reduce overall predation, since the sheer volume of juvenile fish might overwhelm predators, leading to an overall reduction in predation rates.

But Graves said preliminary data from the 2008 migration with "lots of steelhead" migrating inriver, have shown that birds at Crescent Island, near the confluence of the Snake and Columbia, were selecting juvenile steelhead as prey to the exclusion of chinook. "It gets real complicated out there," he said, when scientists try to sort out all the factors in the food chain.

Corps' biologist Turner said his agency was looking at the report to see if there were any feasible research objectives that could be added to their 2009 program. At this point, that seems unlikely, because of financial constraints. The questions raised by the science panel may never be answered.

Besides, the COMPASS model has already spit out an answer that's buried deep in the administrative record recently presented to the court in the latest BiOp litigation. It says the court-ordered pro-spill, less-barging regime that has been in place since 2005 would reduce overall steelhead returns by 18 percent over the new BiOp's May operation. -B. R.

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