Testimony of Earl C. Weber
9/14/00 - Delivered before the Committee on Environment and Public
Mr. Chairman and members of the subcommitee, thank you for this opportunity to present you with my scientific perspective on salmon restoration in the Columbia River basin. My name is Earl Weber. I am a Senior Fisheries Scientist on staff at the Columbia River Inter-Tribal Fish Commission. The Commission was formed in 1977 by resolution of the Nez Perce Tribe, the Confederated Tribes of the Umatilla Indian Reservation, the Confederated Tribes of the Warm Springs Reservation of Oregon, and the Confederated Tribes and Bands of the Yakama Nation. The Commission allows for coordination amongst the four tribes and provides technical assistance to ensure that the resolution of outstanding treaty fishing rights issues guarantees the continuation and restoration of the tribes' fisheries into perpetuity.
On behalf of the tribes, I am providing this testimony as a Fisheries Scientist involved in the Plan for Analyzing and Testing Hypotheses (PATH). Several years ago the National Marine Fisheries Service (NMFS) initiated the PATH process as a means of evaluating potential management actions aimed at restoring Snake River stocks. PATH has employed a decision analysis framework that takes uncertainties with respect to these potential management actions into account. More importantly, PATH held rigorous, formal scientific debates that included a weight of evidence approach for evaluating scientific evidence, including the potential for salmon recovery through actions other than additional management actions or modifications of the hydroelectric power system.
In its Draft Biological Opinion (BIOP) on the Operation of the Federal Columbia River Power System, released July 27, 2000, the NMFS acknowledges the high risk of extinction for ESA-listed salmon stocks in the Snake River. NMFS also acknowledges that breaching the earthern portions of the four dams on the lower Snake River provides the best opportunity for recovering these listed stocks. However, rather than recommending breaching, NMFS postpones breaching these dams in favor of other actions. These proposed actions largely consist of unspecified efforts to improve survival in non-hydropower system areas and a continued reliance on the transportation system to mitigate for hydropower system losses.
In taking this stance, NMFS has ignored available technical information developed by the PATH and other technical experts. Nor has NMFS attempted to analyze and arrange information in a way that illuminates a path between the proposed actions and recovery for all listed stocks of salmon. First, NMFS has taken only selected, optimistic pieces of information from the total amount available through the PATH process. Second, NMFS has failed to look at the information from the standpoint of the feasibility of management actions to recover all listed Snake River salmon stocks.
My testimony focuses on two general areas that have been the focus of PATH in recent years. First, my testimony will provide evidence that transportation is not mitigating for hydropower system losses and that other factors are not responsible for hampering what might otherwise be a successful transportation program. Second, my testimony will show why it is unlikely that recovery will be achieved by improving survival in non-hydropower system arenas.
The BIOP tacitly assumes that transportation is mitigating for hydropower system losses. In making their case for the continued transportation of juvenile salmon in barges, NMFS first omits important information useful for evaluating transportation and, second, tacitly supports the hypothesis that transportation is working but that other factors are masking its success. Neither of these assumptions is supported by scientific evidence. In fact, available scientific evidence shows transportation to be a failed management tool for the recovery of salmon stocks.
2.1 Transportation does it work?
Historically, transportation was evaluated by comparing the survival of transported fish with that of non-transported fish. Two groups of fish were marked and one group was placed in the barge or truck (transport group) and the other group was released back into the river as a "control." The survival rate of each of the two groups of fish was calculated when they returned to the river as adults. The ratio of their survival rates was then calculated. If the Transport-to-Control-Ratio (TCR) was greater than 1:1, transportation was deemed successful.
However, in a review of the juvenile transportation program, Mundy et al. (1994) found the TCRs were "moot" if the survival of the transported fish was not high enough to insure survival of the stock in the long term. Typically, the Smolt-to-Adult survival of the transported fish stocks was much less than one percent. PATH concurred and established a survival goal for spring/summer chinook of from two to six percent, based on the past survival of Snake River chinook and recent estimates from a downriver index stock , Warm Springs spring chinook (Toole et al 1996). The following graphic shows the Smolt-to Adult-Return (SAR) of transported wild Snake River spring/summer chinook.
Note that in recent years (1988 1997) SARs were measured with highly accurate Passive Interrogation Transponder (PIT) tags. During this period the average survival rate was less than 0.5%, far less than the minimum goal of two percent and an order of magnitude less than the four percent which is approximately the level needed for recovery. The survival goals and the survival information developed by a panel of interagency agency and trial technical experts (PATH), including NMFS staff, was omitted from the BIOP.
Interestingly, the recent PIT tag data also shows that transportation may not be affording even a relative advantage over smolts (juvenile fish) migrating down river through the turbines of the dams. For example, Kiefer (in prep) found that juvenile Snake River spring chinook that migrated to the ocean through the hydrosystem without being handled or bypassed returned at rates above those of transported fish in two of three years for which data are available.
Low SARs are consistent with other studies of Snake River Spring/summer chinook. Deriso et al. (1996) and Schaller et al. (1999) analyzed adult (recruit per spawner) data and found that the differential mortality between seven Snake River spring chinook stocks and six downriver control stocks averaged approximately 0.17 per project, which equates to a mortality of over 80% for eight projects. Because this level of mortality was far in excess of that indicated by passage models, a statistic, D, was formulated to quantify the level of differential mortality due to collection and transportation relative to the delayed mortality experienced by fish migrating inriver. Like their predecessors, the Transport-to-Control Ratios, D values are not in and of themselves important. While D values close to one are better than D values close to zero, NMFS asserts that high values of D indicate differential mortality is due to something other than problems with the transportation program. D values are important in an analytical sense only if it can be assumed that differential mortality has nothing to do with the hydropower system. Therefore, it is incumbent on NMFS to explain the source of extra mortality. To date, NMFS has referred to genetic differences between Snake River spring chinook and their downstream control stocks. But genetic differences are not by themselves agents of mortality and must be at least conceptually linked to one or more biological mechanisms. These would include starvation, predation or disease.
It is unrealistic to believe that some stocks of the highly migratory chinook would suddenly find themselves unable to locate prey in the North Pacific. The trophic structure of the eastern North Pacific Ocean is based on large scale wind driven upwelling events that produce large, temporary gyres. These gyres bring cold, nutrient rich water to the surface where food chains forms. Gyres repeatedly form and dissipate throughout the range of spring/summer chinook, which extends from Northern California to the Gulf of Alaska. Because both the Snake River chinook and their downriver (control) counterparts occur within this range, it seems unlikely that the Snake River chinook would become unable to locate prey while the downriver stocks continue to feed successfully. Likewise, it is difficult to believe that Snake River fish would begin to encounter a previously unencountered predator while the downriver fish proceed unmolested.
Although some have emphasized the importance of ocean cycles, the fact that all Snake River salmon stocks obviously haven't collapsed every sixty years, or on any other potential cycle, indicates that a climatic cycle is not to blame. Instead, this hypothesis would seem to require that a new and unexplained oceanic phenomenon would have to have come into play coincidentally with the construction of the last four dams. It is important to note that during PATH's Weight Of Evidence process, the Scientific Review Panel assigned very low weights (ranging from a 1% to a 20% likelihood) to the Regime Shift Hypothesis as shown in the following table:
Reviewer Carpenter Collie Saila Walters
Weight 0.01 0.1 0.15 0.2
Overall, these were the lowest weights assigned by the SRP for any hypothesis. NMFS ignored the Scientific Review Panel and the Weight Of Evidence process in the BIOP.
Conversely, disease appears to be a likely contender for the differential mortality. In fact, NMFS described a scenario over a decade ago wherein a combination of stress and injury sustained during bypass, collection and transportation, causes the ubiquitous but generally asymptomatic Bacterial Kidney Disease (BKD) to flourish (Williams 1989). This phenomenon is well known among fish pathologists (see for example Warren 1991). BKD takes several months to run its course and thus mortality would not occur until the early ocean life stage, the stage at which differential mortality is thought to occur. If NMFS now believes this hypothesis to be untrue, they should provide a more plausible explanation.
To summarize, D values, like Transport-to-Control Ratios (TCRs), are relative measures used to relate the survival of transported fish to that of inriver fish. There is no logical reason to believe that high D values exonerate transportation. High values of D are only important in a quantitative sense if one assumes that differential mortality is unrelated to stress and injury in the hydropower system. The only plausible hypothesis for delayed mortality is linked directly to the hydrosystem. If NMFS wishes to provide a more plausible scientific hypothesis for extra mortality, they need to provide a biological mechanism whereby, 12 to 13 million years after speciation, and concurrent with the development of the hydropower system, the Snake River spring chinook stocks underwent severe declines that the downriver control stocks did not experience.
3 Potential for recovery through other Hs
The major thrust of the BIOP is that salmon restoration may be possible entirely through improvement in areas other than the hydropower system (i.e., through additional restrictive management actions in habitat, hatcheries and harvest.). This assumption is contradicted by available technical information.
While good habitat is important, one must remember that there are wilderness areas in the Snake Basin yet there are still dwindling spring chinook populations. For example, Sulfur Creek and Marsh Creek are in prime habitat areas. But in 1994 and 1999, no fish returned to Sulphur Creek and in 1995 and 1999 no fish returned to Marsh Creek. It is, therefore, unrealistic to assume that habitat improvement alone will recover spring chinook stocks. Likewise, there are no identifiable opportunities for recovering the Snake River sockeye stock through habitat manipulation.
The greatest "habitat" problem for fall chinook is the severe reduction of spawning habitat caused by the Hell's Canyon dam complex that blocked upstream migrations, and the lower Snake River dams that encroached on their remaining spawning area downstream of Hell's Canyon. NMFS acknowledges that the removal of the four lower Snake River dams will increase spawning and rearing habitat up to 77 percent, with the potential to add 5,000 spawners.
Note also that some of the more important habitat problems are found within the hydropower system. These include nitrogen gas super saturation, elevated water temperatures and the substantial reductions in water velocities that occur in reservoirs. These water quality issues affect all Snake River salmonids and other anadromous and resident fish.
With spring chinook harvest rates in the range of seven to nine percent, opportunities for recovery through harvest reductions are almost nonexistent. Harvest rates for Snake River summer chinook and sockeye stocks are lower than those for the Snake River spring chinook stock. At least temporarily, improvements in escapements through harvest reductions are possible for fall chinook and, to a lesser extent, steelhead, but that will not benefit spring/summer chinook or sockeye.
This approach has several potential facets. Hypothetically, high densities of hatchery fish could negatively impact Snake River wild stocks. But four of the seven Snake River spring/summer indicator stocks, including the aforementioned Sulphur and Marsh Creek stocks, have no hatchery programs. For these and many other stocks a reduction or elimination of hatchery fish is impossible.
A second hypothesis suggests that hatchery fish, particularly the larger steelhead, may stress spring/summer chinook in the unnatural bypass/collection systems and barges. This further stress, mixed with injury and disease transmission (Williams 1989), appears to be the most likely reason for the low survival of transported spring chinook. However, recent data show that even when steelhead are absent or present in low densities, survival rates (SARs) for chinook are often zero and always less than one percent (Peters and Marmorek 2000; Appendix D). One could reasonably question the wisdom of dismantling a moderately successful program (hatchery steelhead) in what would appear at the outset to be a fruitless attempt to raise transportation survival to the two to six percent range.
Mr. Chairman, that concludes my testimony. I am prepared to answer your questions, or those of other committee members, now. I am also available to answer any written questions that you wish to provide to me for the benefit of the record.
5. Literature cited
Peters, C.N. and D.R. Marmorek. (compls./eds.) 2000. PATH: Preliminary evaluation of the learning opportunities and biological consequences of monitoring and experimental actions. Prepared by ESSA Technologies Ltd., Vancouver, BC, 150pp.
Toole, C., A. Giorgi, E. Weber and W. McConnaha. 1996. Hydro decision pathway and review of existing information. In: Marmorek, D.(ed). 1996. Plan for Analyzing and Testing Hypotheses (PATH): Final Report on Retrospective analyses for FY 1996. Prepared by ESSA Technologies Ltd., Vancouver, BC.
Schaller, H.A., C.E. Petrosky and O.P. Langness. 1999. Contrasting patterns of productivity and survival rates for stream-type chinook salmon (Oncorhynchus tshawytscha) populations of the Snake and Columbia Rivers. Can. J. Fish. Aquat. Sci. 56: 1031-1045.
Warren, J.W. 1991. Diseases of hatchery fish. U.S. Fish and Wildlife Service, Pacific Region Publication. 90pp.
learn more on topics covered in the film
see the video
read the script
learn the songs