Dr. Michael Schiewe is a Fishery Biologist specializing in the ecology of Pacific salmon. He received his undergraduate education from Humboldt State University in northern California in 1968, and his Masters and PhD degrees from the University of Washington in Seattle, in 1976 and 1980, respectively. Dr. Schiewe's early research focused on variety of fish health issues, ranging from infectious diseases of fish and shellfish, to the effects of environmental contaminants on marine and anadromous fish. For the past 12 years, he was Director of the Fish Ecology Division and Senior Salmon Scientist at NOAA Fisheries' Northwest Fisheries Science Center. In this capacity, he directed a variety of research, including studies on biodiversity and population structure, fish passage at dams, habitat requirements, artificial production, and estuarine and ocean ecology of Pacific salmon. Dr. Schiewe is currently a Senior Fishery Scientist at Anchor Environmental LLC in Seattle, Washington.

Gerry Milliken asks:
Hi Mike,
How can Androscoggin Dam operators in Brunswick, Maine say that "shad don't do ladders" when 100,000 shad a day use 60 foot high Bonneville dam ladders on Columbia River? Report says that shad are pretty beat up with much scale loss for the few that even make it halfway up Androscoggin Dam. Video cameras show shad entering ladder, with fewer and fewer at higher steps. Shad also seem to pass dams in PA and CT.

How can we get effective dam ladder [plans or at least review of dam operator's ladder plan] for a 10 foot blocked Falls on what was once second largest salmon river in Maine? I believe there is financial pressure for dams not to accurately count fish at the first dam on a river, so as not to pay for ladders at their upriver dams. The government does not fund ladder construction in Maine.

How can we show [or document] attraction flow to Ticonic Falls rather than tailrace during Salmon spawning months?

Will Salmon be dead-ended in the 1000 feet between tailrace proposed Lift and upstream Falls?
Thank you,
Gerry

Schiewe's response:
Your questions regarding shad passage are specific to a location I'm not familiar with. What I can do, however, is briefly summarized a few of our experiences with shad passage at Columbia River dams…highlighting what we've found to generally work and what doesn't. It's important to recognize, however, that we don't always understand why a structure functions well in one location but fails miserably in another. There obviously must be subtle differences in design, flows, environmental conditions, etc. that evoke different responses by fish. In the end, there is no guarantee that a particular design or operating scenario that works well at one location will work at another.

Although the fish ladders on the Columbia River were designed for the upstream passage of salmon, as you note several are also quite effective in passing adult shad. In general, the Columbia River ladders are constructed with a rise to run of 1 to 10 ft or greater, and are operated with about a 1 to 1.3 foot head. This produces a water velocity of between 4 to 8 feet per second in the ladder. Most ladders are composed of a series of weirs or steps; each of which is constructed with either a notched overflow section or an underwater orifice…or both. As a general rule, the majority of the salmon pass upstream using the underwater orifices; whereas; the shad almost exclusively use the notched surface overflow to pass. In fact, a very effective way to reduce the number of shad in the Columbia would be to block the notched overflow weirs. The reason I mention this is that unlike the East Coast, shad are not native to the Columbia River (they were introduced in the late 1800s), and there is concern that shad are competing with the native salmon and hence may be contributing to their problems.

While I cannot be much more specific than this without more detailed information and knowledge of the location, I can suggest some additional resources that you might want to consult for addition information.

Fish Passage Center
2501 SW First Ave., Suite 230
Portland, OR 97201
503-230-4099

Norwest Region
National Marine Fisheries Service
Hydropower Program
525 NE Oregon St., Suite 500
Portland, OR 97232
503-230-5417

Dawn Gilkison asks:
Alan Alda's narration states that "a higher proportion of barged fish return as adults, compared to those that came down the river on their own." Could you give me a reference from the scientific literature containing data that supports this statement?

Schiewe's response:
Since the 1970s there has been a series of evaluations comparing the survival and return of transported versus non transported fish. The majority of these studies have indicated a higher returning proportion of transported when compared to non transported fish. However, the results varying by species of salmon and the years over which the evaluations were conducted. In some of the more recent years in which passive integrated transponder (PIT) tags were used for these studies, fishery scientists have been able to evaluate the effects of transportation in much greater detail…to include on a week-by-week basis throughout the migration season. In some of these studies it has been found that there are periods during which the non transported fish survive and return at a higher rate than do the transported ones.

Citations from the scientific literature that report results of juvenile salmon transportation studies include the following:

Ebel, W.J., D.L. Park, and R.C. Johnson. 1973. Effects of transportation on survival and homing of Snake River chinook salmon and steelhead trout. Fishery Bulletin 71: 549-563.

Slatick, E., D.L. Park, and W.J. Ebel. 1975. Further studies regarding effects of transportation on survival and homing of Snake River chinook salmon and steelhead trout. Fishery Bulletin 73: 925-931.

Ebel, W.J. 1980. Transportation of chinook salmon, Oncorhynchus tshawytscha, and steelhead, Salmo gairdneri, smolts in the Columbia River and effects on adult returns. Fishery Bulletin 78: 491-505.

Ward, D.L., R.R. Boyce, F.R. Young, and F.E. Olney. 1997. A review and assessment of transportation studies for juvenile chinook salmon in the Snake River. North American Journal of Fisheries Management 17:652-662.

Sandford, B.P., and S.G. Smith. 2001. Smolt-to-adult return percentages for Snake River Basin salmonids, 1990-1995. Journal of Agricultural, Biological, and Environmental Statistics: 7:243-263.

Citations for some of the recent research reports that include adult return data for the 1995, 1996, 1998, and 1999 migration years are as follows:

Harmon, J.R., D.M. Marsh, N.N. Paasch, K.L. Thomas, K.W. McIntyre, B P. Sandford, and G.M. Matthews. 2000. Research related to transportation of juvenile salmonids on the Columbia and Snake Rivers, 1999. Report to U.S. Army Corps of Engineers, Contract E86960099. 28 p.

Marsh, D.M., J.R. Harmon, N.N. Paasch, K.L. Thomas, K. W. McIntyre, B. P. Sandford, and G. M. Matthews. 2001. Research related to transportation of juvenile salmonids on the Columbia and Snake Rivers, 2000. Report to U.S. Army Corps of Engineers, Contract E86960099. 28 p.

Marsh, D.M., J.R. Harmon, N.N. Paasch, K L. Thomas, K.W. McIntyre, B.P. Sandford, and G.M. Matthews. In review. Research related to transportation of juvenile salmonids on the Columbia and Snake Rivers, 2001. Report to U.S. Army Corps of Engineers, Contract E86960099. 33 p.

Jon Lolley asks:
Hello Mike. I am a student at Boise State University. I am currently an intern for the Small Business Development Center. I have been assigned to help a man named Tom Bradley promote and sell a fish scale he has invented. The scale has many features that would make taking samples of fish weight and length much faster. Can you think of any research being conducted on fish (govt or commercial) in which samples of weight and lengths of fish are being frequently measured? This scale could speed along the process of their research greatly.

Schiewe's response:
There are literally thousands of fisheries studies conducted throughout North America each year that involve weighing and measuring fish. Although there are several automated systems already available that make this typically tedious job less onerous, there is always room for improvement. For starters, I suggest you contact any of the federal, state, tribal, and university laboratories and field stations scattered throughout the Pacific Northwest and arrange to demonstrate your device. I'm sure that the researchers would be happy to discuss their projects and needs with you.

Scott Levy asks:
What would you estimate are the odds that we will follow the 2000 Biological Opinion?

Is it possible to triple survival in some life stage of Idaho salmon/steelhead without the removal of the 4 Lower Snake River dams?If yes, please describe what efforts would provide these results

Schiewe's response:
The first question refers to the Biological Opinion written in the year 2000 by the National Marine Fisheries Service. This Opinion covers operation of the 29 dams of the Federal Columbia River Power System between the years 2000 and 2010. The Biological Opinion describes what are referred to as "reasonable and prudent alternatives" or RPAs that when implemented by the "actions agencies" are designed to avoid jeopardizing the continued existence of the listed salmon. This is a regulatory document; and the short answer to your question is that, "I don't know." I suggest you contact the federal agencies that are governed by the Biological Opinion and ask them this question. The action agencies for this Opinion are the US Army Corps of Engineers, the Bureau of Reclamation, and the Bonneville Power Administration.

The second question involves the role of the four lower Snake River dams in the decline and continued depression of Snake River salmon, and the potential role their removal might play in recovery. This has been a very contentious issue in the Pacific Northwest during the past decade, and is one that has generated substantial coverage in the popular press. While it is relatively clear to everyone involved that removing the dams would be good for fish, the exact role that continued operation of dams is playing in the continued depression of the salmon populations passing them is the subject of much debate.

The manner in which you ask the question suggests that you think that removing the four lower Snake River dams would triple the survival of some life stage of Idaho salmon and steelhead. I'm unaware of any credible scientific study or analysis that would support this conclusion, and would be interested in learning of it if it exists. In contrast, in a paper recently published Dr. Peter Kareiva and colleagues (Kareiva, P., M. Marvier, and M. McClure. 2000. Recovery and management options for spring/summer chinook salmon in the Columbia River basin. Science 290:977-979) it suggests otherwise…that removing the 4 Snake River dams would be unlikely to by itself effect recovery Snake River salmon. Using 1980 to 1993 returns of spring chinook salmon populations originating in the Salmon River (a tributary of the Snake)as a baseline, Kareiva et al. found that none of the populations were surviving at a rate high enough to replace themselves…that is, each successive generation was becoming less abundant. Using an age-structured matrix model (a common tool in population dynamics modeling), Kareiva et al. showed that even improving upstream and downstream passage survival to 100% (a level unlikely even on an undamned river) the overall life cycle survival of these chinook populations would still not improve enough to achieve replacement. Further, these investigators concluded that the only conceivable way that removal of the Snake River dams could effect such a large improvement in survival would be if their removal eliminated a very high level of mortality that was occurring as a result of their presence, but at some later life stage. Such a "deferred mortality" has been proposed by some, but has yet to be demonstrated.

The bottom line is that the dams are one of many factors that contributed to the decline of Snake River salmon. I'm not aware of any "silver bullet" that might triple survival of any particular life stage. Recovery of salmon in the Columbia River will no doubt require improvements in survival throughout the life cycle, and logically involve careful management of hatcheries, continued efforts to improve passage survival, carefully controlled harvest, and landscape-scale habitat restoration…and last but not least, a return of nearshore oceanic conditions that support much higher marine survival. While the latter is obviously beyond the control of humans, the current evidence does in fact suggest we are entering a period of more favorable marine conditions, and that the salmon are responding with near record returns.