Dams, Politics, and Scienceby John McKern
Columbia Basin Bulletin - March 21, 2003
This is in response to Mr. Masonis and Mr. Stuart in last week's feedback.
I agree that politics more than science sway the issue of dam breaching in the public's eye. Harvest and fish count data from the 1860s to 1930s shows that most of the decline occurred before the four lower Snake River dams were constructed. Other dams that blocked tributaries, mining, logging, road and railroad construction, municipal and agricultural pollution, and overharvest in the ocean, lower river, and up river into the tributaries reduced salmon and steelhead runs from the fabled 16 million to an escapement of less than 500,000 (286,000 chinook) over Bonneville Dam when fish counts there began providing accurate records. Yet you would have the public believe the four Snake River dams caused this decline.
While it is true that the runs continued to decline from the 1960s through the 1990s, and that the Corps' dams were partly responsible, they were not the only cause. Ocean and climate conditions declined from the early 1970s through the 1990s. There was a continuous drought in the Snake River Basin from 1986 through 1995. Despite transportation of large numbers of fish, smolt to adult return rates (SARs) and adult returns to the Snake River declined. There is ample evidence that declining ocean conditions caused SARs to crash to disastrously low levels in rivers from California to British Columbia -- many runs on rivers without dams -- during that same time. For example, Oregon coastal coho runs crashed from over 16 percent SARs to SARs less than 1 percent -- in river without dams. SARs of Keogh River steelhead on Vancouver Island crash by 1000 percent -- with no fish transportation or dams.
In 2002, the National Marine Fisheries Service measured the survival of juvenile spring/summer chinook through the eight-dam Columbia River system. They found survival to be as high or higher than in the 1970s when there were only four dams. Numerous other researchers came up with results showing reservoir survival as high as 99 percent and turbine survivals ranging from 93 percent to 99 percent in 2001 and 2002. The NMFS reported that in-river survival of juvenile spring/summer chinook was 27 percent in 2001 and over 59% in 2002. In a comparable drought year, 1977, NMFS estimated inriver survival to be 0.4 percent. My calculator tells me that is an increase of 6,650 percent in 2001 and 14,65 percent in 2002 compared to 1977. Although it is politically unpopular to say so, there is strong scientific evidence that the Corps' "gadgets and gizmos" have mitigated the detrimental effects of the dams. Furthermore, the Corps is working on surface bypass technology that may further increase survival and significantly reduce spill - helping to reduce our power rates.
Over the past 5 years, the NMFS has been teasing apart the results of fish transportation. They have found that fish transported early (before the first week of May) return at low rates whereas those transported later may return at higher rates. The differences can be SARs of less than 1 percent early in the season to over 6 percent later in the season (the BiOp calls for 2 to 6 percent). Seasonal transport/inriver ratios range from less than 1 to over 3 times as many returns for transported fish. New technology is allowing gathering of better science - better than was available to the NMFS when the BiOp was formulated; better than was available to the Independent Scientific Advisory Board when they reviewed the BiOp. The NMFS is reconsidering the operational demands in the BiOp because better science is becoming available.
Adult returns in the last three years raise serious questions about the claim that breaching the dams would increase survival by "400 percent." Chinook runs at Ice Harbor Dam were under 100,000 by 1961. The runs dropped below 8,000 by 1994 (the tail end of the 30-year drought). In 2001, 925,000 chinook passed over Bonneville, and over 137,000 passed over Ice Harbor. In 2002, over 971,000 chinook passed over Bonneville Dam, and over 215,000 passed over Ice Harbor. By my calculations, the 2001 and 2002 adult returns over Ice Harbor were over 1,700 percent and 2,687 percent higher than the 1994 run. It is true that this trend must continue for some time before recovery can be declared. I don't predict future runs, but the Washington Department of Fish and Wildlife is predicting better than normal runs up the Columbia again in 2003.
It seems that British Columbia fisheries scientists are way ahead of U.S. salmon managers in perceiving and understanding the significance of ocean conditions in the plight of the salmon runs. They have measured SAR swings of enormous magnitudes on undammed, and in some cases, almost totally unperturbed river systems. They believe that not only do salmon migrate back to specific streams, but also they migrate to specific areas in the ocean to rear from juvenile to adult. If those areas have experienced a severe decline in productivity, the salmon are fewer, smaller, weaker, less capable of reaching spawning grounds, and less capable of reproducing than those from areas of higher ocean productivity. In the case of Snake River fall chinook, the ocean area is subject to lower productivity and higher harvest (the west coast of Vancouver Island) than the rearing area of Hanford Reach summer/fall chinook (near the Aleutian Islands). Therefore, Snake River fall chinook have poorer returns than the Hanford fish.
The Canadians also believe that the role of adult salmon in returning nutrients and fertility from the ocean to the spawning and rearing areas is vital. Our salmon managers judge escapement based on the number of fish needed to provide enough eggs to provide enough smolts to provide enough adults, etc., etc. However, if not enough adults return to keep the fertility of the spawning and rearing areas high, survival of those eggs to smolts, and smolts to adults decline.
I believe that rather than harping on the removal of dams that the fisheries science shows have been mostly fixed, the region should concentrate on the effects of ocean conditions and how to adjust fish management to allow the runs to recover. The NMFS is taking a small step in that direction now with their studies of the extension of hydropower system effects into the plume of the Columbia River into the ocean. But they are still assuming that the hydropower system is the big evil. Ocean survival research that identifies where the fish go and what the conditions are where they rear is essential. Salmon rearing sanctuaries in the ocean and increased escapement as well as continuing to restore and protect spawning and rearing areas in freshwater may be required. If, Mr. Stuart, better ocean survival and better spawning ground survival can be provided, the Corps can provide safe passage in between.
As more and better science becomes available, the region has more tools with which to make better decisions. Our Constitution gives opposing factions the right to air differing opinions in public. We must hope that the decision makers, the politicians who listen to our discussions, make the right decisions.
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