Fisheries Scientists Redefine the
by Rocky Barker
Increasing the amount of water spilled over eight Snake and Columbia river dams to keep juvenile fish away from hydroelectric turbines might be enough to recover most of Idaho's endangered salmon populations without breaching dams, new studies suggest.
A state, tribal and federal science team that has been working since 1996 is urging federal fish and wildlife officials and dam managers to change their management to test the theory, which is based on a dramatic increase in data collected over the past decade.
"The fish are talking to us and we're getting better at listening to what they're telling us," said Ed Bowles, chief of fisheries for the Oregon Department of Fish and Wildlife.
The research suggests that a 15 percent to 20 percent increase in the amount of water that now spills over the dams -- for a total flow of just more than half the rivers' water -- would more than double the number of salmon that survive to return to spawn. That's enough to support sustainable populations of wild stocks of chinook and steelhead within 48 years.
In previous survival studies going back to 1996 -- including a review by Idaho's Department of Fish and Game -- the only management option that could reach those survival numbers was breaching the four federal dams on the Snake River in Washington state.
The new study won't end the debate. Opinions differ on whether the cost of extra spill is worth the benefits and whether removing the dams wouldn't be cheaper in the long run.
Since the system of dams was built on the Columbia and Snake rivers from the 1930s through the 1960s, populations of salmon and steelhead have plummeted. Some had their access to spawning grounds blocked; others were killed traveling downstream, sucked into deep reservoirs and spit through the turbines. Some fish die outright at the dams; others are left too weak to make the trip to the ocean and back.
For the past 20 years, environmental and industry groups, Indian tribes, Northwest states, power companies, and the federal agencies that oversee dams, power and fish have been in court arguing over whether -- and how -- to save the iconic fish that define the Northwest and have given sustenance to its residents for millennia.
THE PROMISE OF 'SPILL'
Charles Petrosky, an Idaho Fish and Game biologist who's been involved in all of the studies, said he's not ready to simply say that increasing spill would be as successful, biologically, as dam removal.
"It may get us into the ballpark," Petrosky said. "I don't think it changes the past (conclusions), but it gives us something in between that has a lot of promise, and we ought to explore it."
The findings were released April 12 at the annual meeting of the Comparative Survival Study group in Portland. The group was set up in 1996 to estimate the effects of the Columbia and Snake dams on salmon through their life cycle.
"Spill" is the term given to river water that flows over the dam's spillways rather than through its power-generating turbines. What makes an increased-spill plan more appealing than breaching dams is that it helps more than the four stocks of endangered salmon that live upriver of the dams. It also would help migrating salmon that spawn in the lower parts of the Columbia River system and its tributaries.
There are nonbiological benefits as well that could play just as big a role in any final management decision:
COSTS OF MORE SPILL
Even so, there are costs to a plan that requires more aggressive spill.
Sending water away from the dams' turbines reduces the amount of electric power that can be generated and sold, reducing the revenue that the Bonneville Power Administration gets for marketing hydropower. BPA has supported limited spilling as a part of the court-supervised "biological opinion" for operating Snake and Columbia dams, but has resisted expanded plans. Bonneville also rejects plans that put all the burden of recovery on the dams.
"The current bi-op is based on collaboration and science and (it) defines the performance the hydrosystem needs to achieve," said BPA spokesman Michael Milstein. "That's what we're focused on."
Terry Flores is executive director of Northwest RiverPartners, an alliance of utilities, farmers and barging interests that has supported the existing federal dam plan -- a plan that advocates neither greater spill nor dam removal. She said she has not seen the Comparative Survival report, but is skeptical that it says anything new.
"It sounds like the same soundbite we've heard for years: More spill is better," Flores said.
The current federal management plan calls for "adaptive management" -- adapting river operations as new science emerges. Ritchie Graves, the National Marine Fisheries Service branch chief who oversees management of the endangered species in the Snake and Columbia, said its scientists see the data differently than the scientists whose research supported breaching and, now, more spill.
But he said the hypothesis is something that can be tested, and his agency, also known as NOAA Fisheries, is considering it.
"We're approaching this cautiously," Graves said. "We have to have more conversations with them."
UNRAVELING SPILL'S BENEFITS
The current federal plan, often simply referred to as the bi-op, had the support of the states of Idaho, Montana and Washington, and most of the region's Indian tribes. The Nez Perce Tribe and the state of Oregon opposed it. It was struck down in 2011 as insufficient for salmon recovery by U.S. District Judge James Redden.
Salmon returns have improved since 2000, due in part to cooler ocean conditions near shore, which reduce predator numbers and create upwelling of currents that carry additional food. Those factors are outside of human control. But improved conditions in the rivers, due to court-ordered spill and fish-passage devices installed at many federal dams, also have contributed.
Biologists are predicting a good 2012 salmon season, which began this month.
Bowles, the Oregon chief of fisheries, said the new data show that spill benefits fish in ways biologists previously didn't understand.
Not only does it divert the juvenile salmon away from the powerhouses, it also improves their survival in the Pacific after they leave the Columbia. It speeds their trip through the rivers and estuaries, meaning more survive to get to the ocean.
The larger salmon returns of the past decade and better tagging and monitoring of salmon have dramatically increased the amount of information scientists have to work with, Bowles said.
These most recent survival findings support Oregon's official stance, which has called for an aggressive approach to salmon management that doesn't include breaching.
The Nez Perce and the group Save our Wild Salmon, a coalition of sporting businesses, fishing groups and environmentalists, have long advocated removing the four dams to recover the fish.
Nicole Cordan, the coalition's policy and legal director, said the findings are promising for the salmon, but they don't take dam removal off the table.
That's partly because added spill isn't enough to recover Idaho's Snake River sockeye, which nearly went extinct.
Increased spill will cost money, likely making it and other measures necessary for salmon recovery more expensive in the long run than simply removing the four dams, she said.
"We've always thought the economics and the science pointed to breaching to be the easier option," she said.
bluefish: recommends this sidebar as an very good primer for beginners to this complicated/intertwined subject.
SALMON SCIENCE 101
What's at issue?
Salmon populations having been dropping in the Columbia River Basin from the estimated 8 million to 16 million that returned annually 150 years ago. Wild stocks dropped so far that, beginning with the Snake River sockeye salmon in 1991, 13 species of salmon were listed as threatened or endangered. In addition to sockeye, Idaho's Snake River spring-summer chinook, fall chinook and steelhead were listed as threatened.
What did that do?
That forced the Pacific Northwest to restrict all sorts of activities that harm salmon, including irrigated farming, fishing, logging, streamside development and barge transportation. Most of all it has focused attention on the hydroelectric dams on the Columbia and Snake rivers that have been among the most prolific juvenile salmon killers.
I thought there were ladders at the dams to protect the salmon.
Those help the returning adults make the trip from the Pacific upriver through the eight dams back to Idaho. But the ladders don't help the juvenile salmon that are migrating downriver to the Pacific right now.
What happens to these juveniles?
Some are chopped up or injured in the hydroelectric turbines; others are eaten by predators in the slow-moving reservoirs created by the dams. Still others go through a bypass collector that keeps them out of the turbines. Some juvenile fish are scooped up and loaded onto barges and hauled below the last dam on the Columbia, Bonneville Dam near Portland. Others go over the spillway when water is allowed to spill, diverting the fish away from the turbines. Some of these fish go through "fish slides" built to make the spill easier on them.
Why do they put them in barges?
By collecting the fish before they end up in the turbines, dam operators can keep the water running through the turbines, producing power and revenue. Spill for fish migration takes water away from electrical generation.
So why not just do more barging? Wouldn't that give us more fish AND more power?
That has been the federal strategy since the 1980s, but research shows a high number of barged fish later died in the Pacific. State, tribal and U.S. Fish and Wildlife Service biologists attributed this lower survival to the barging. All fish populations that go through the hydroelectric system suffer reduced survival rates, but the research suggests the fish in the barges suffer the most. Other federal biologists dismissed this theory, saying the mortality was caused in the ocean.
What was the alternative?
Research in the 1990s suggested that for the four species of salmon that spawn in Idaho, removing the four federal dams on the Snake River in eastern Washington was the most effective and perhaps the only way to recover these Idaho fish. Together, those four dams -- Ice Harbor, Little Goose, Lower Monumental and Lower Granite -- produce less power than the single John Day Dam on the Columbia. But each additional obstacle to the salmon migration added to cumulative salmon deaths.
A series of lawsuits have forced federal managers to work with these scientists; a "spread the risk" philosophy has been worked into the series of court-ordered plans, called biological opinions. As the evidence of delayed mortality has grown stronger, levels of spill have increased. In 2011, the Comparative Survival Group said: "The evidence presented for … delayed mortality arising from earlier experience in the hydrosystem is strong and convincing." This year, the data showed that the delayed mortality was higher for all juvenile fish that avoided the turbines by barge or bypass, and that it was highest for the Snake River salmon that had to pass eight dams.
What does this mean for spill?
The data show that spilling the fish not only keeps the young salmon out of the powerhouse, but also improves survival in the estuary and in the Pacific. It also speeds their travel time through the hydrosystem, when they are most vulnerable.
"We knew spill was good; we just didn't know how good," said Michelle DeHart, director of the federally funded Fish Passage Center in Portland.
So now what?
After spending more than $8 billion to restore the fish that are living symbols of the Northwest's wild character, the river-connected economy -- including Idaho farmers and the inland Port of Lewiston -- remains under a cloud of uncertainty. U.S. District Judge James Redden ruled that the Obama administration's plan to manage Columbia Basin dams didn't go far enough to revive and protect Northwest salmon runs. He ordered a new plan by 2014.
He refused to take dam breaching away as an option and ordered federal officials to continue spilling. Redden retained jurisdiction over the case until the federal government writes a new plan. He has since retired and now U.S. District Court Judge Michael H. Simon has the case.
learn more on topics covered in the film
see the video
read the script
learn the songs