Dam removal and salmon science


Pacific salmon face grim times.  The plight of Canada's Fraser River sockeye has fixated fishers, scientists, and the state for decades.  Concern has grown since the 1990s as annual runs went from bad to frightening, but then last summer’s run was bafflingly great.  The Canadian government federal government in Ottawa formed the Cohen Commission in November 2009 to assess the situation.  It is still grinding through a very complex set of riverine and oceanic factors, and it is not clear members can reach consensus by their current deadline of June 30.

Evolve or die:  that seems to be the theme of many recent events. The Cohen Commission is grappling with a range of issues that include, but are not limited to, rising river temperatures, degrading ocean conditions, and harmful effects from salmon farms.  Many members seem inclined to blame a combination of the above and perhaps more, but scientific explanations for how elements interact lag behind, and controlled experiments [pdf] may not be possible.

We are witnessing very rapid changes in ecology, technology, and politics, all of which are selecting for dynamic traits.  Populations and arguments incapable of adapting may well go extinct, and this applies to fish and environmentalists.

Environmental change may moot even cutting edge research.  A forthcoming study from ICES has linked population-level shifts in Pacific salmon abundance to climate change.  Findings are complicated by the ever changing extent of artificial fish propagation and by assumptions about relationships between abundance and harvests that seem debatable, but the take home message is chum and pink salmon have done better than sockeye and much better than chinook and coho, and success corresponds to more northerly ocean ranges, itself a proxy for climate change.  Even worse news came last week in the journal Science, when researchers announced that the Fraser’s warming waters pose lethal risks to sockeye.  The authors try to be hopeful but admit that “warming river temperatures could exert strong selective pressure for physiological adaptation,” which is a polite way of saying some stocks must evolve or die.

This is unnerving enough for people who depend on salmon, but counterbalancing trends in technology pose additional threats to dearly-held assumptions.  The mantra has long been that mainstem dams on the Columbia and Snake Rivers are “fish killers,” and the only rational option is dam removalA study in 1997 [pdf] revealed that efforts to modify screens and spill flows to help juvenile salmon remained woefully short of acceptable thresholds.  A 2000 study suggested that even if Snake River dam modifications worked perfectly, runs might go extinct because of downstream dams and bird predation.  A 2004 study [pdf] found adult salmon still struggling to migrate upstream.  At one time all the research seemed to damn dams, but the situation is changing.

Nothing in what I write below should be construed to suggest that all dams are fine or that dam breaching cannot help some stocks, but dam debates are getting more complicated.  The growing sense of crisis for Columbia basin species forced governments to devote more resources [pdf] to aid salmon, shad [pdf], eulachon [pdf], and lampreys, and there is hard evidence that at least some of these reforms work.  Consider the fish transfer facility at Round Butte Dam on the Deschutes River.  Adult chinooks are recolonizing their historic ranges above Lake Billy Chinook, the facility is redirecting the reservoir’s formerly stagnant waters, and juveniles are surviving downstream transport.  Make no mistake:  a helluva lot of money was poured into this venture, money that would not have materialized but for the Federal Energy Regulatory Commission’s mandatory relicensing process and the Confederated Tribes of Warm Springs’ treaty rights, but touring the dam two weekends ago for the second time in a year gave me pause.  Watching technology create a current where there was none, and reading encouraging findings about the fish capture and transfer projects, I began to wonder if I was seeing the future.

The implications of climate change on the Fraser, awareness that hydroelectricity may be a critical means of reducing carbon loading, and the ability of dams to regulate river temperature for fish life may quickly shift the ground in this debate.  Add to that the Bureau of Reclamation’s report last week [pdf] detailing plans to add hydroelectric generation capacity at perhaps seventy sites around the West, and a crappy western economy still needing federal stimulus, and my gut says the thirty-year hiatus in western dam building might be coming to an end.  If that is the case, then the old arguments may no longer be germane.  Which is okay, really.  The more I watch ecology and technology change, the more persuaded I am that our political conversations about dams must grow more nuanced.

We who care about fish in the West also need to evolve or die.

Essays in the Range blog are not written by High Country News. The authors are solely responsible for the content.

Joseph Taylor teaches in the history department at Simon Fraser University, in Vancouver. He is the author of Pilgrims of the Vertical: Yosemite Rock Climbers and Nature at Risk, which won the National Outdoor Book Award, and Making Salmon: An Environmental History of the Northwest Fisheries Crisis, which won the American Society of Environmental History’s best book award. He lives in Oregon.

Image of sockeye salmon in Canada courtesy Flickr user Jason Drury.

Matt S.
Matt S. Subscriber
Apr 08, 2011 03:24 PM
Sorry Joseph, but you are going down the wrong path here and seem to have drank the "clean hydro" (think "clean coal") Kool-Aid.De-Evolving.

Your link between northern stocks of salmon doing better than southern stocks as a result of climate change fails to acknowledge that northern watersheds are in better shape, less urbanized, and less dammed than south.

Dams cause fragmentation of habitat, reduction and isolation of populations, inbreeding, and other outcomes that reduce the ability of salmon to evolve. Even "partially" passable dams (like your Round Butte) severely alter migration timing, water quality, water chemistry, encourage non-native predatory species, are filling with sediment, structurally degrading over time, and have numerous other negative impacts to salmon and the river ecosystems they have dammed.

You are again missing the point when you write "The growing sense of crisis for Columbia basin species forced governments to devote more resources to aid salmon...and there is hard evidence that at least some of these reforms work." Revisit the numbers and studies you are referring to and make that same claim for "wild" salmon populations. You can't! The Obama administration has mostly followed the failed Bush policies and is betting on your "technology" to artificially "make" the salmon numbers look better while dumping billions into unsustainable practices like barging juveniles around the real problems; dams, and wasting our tax dollars on inland aquaculture experiments; hatcheries, that are further decimating our wild numbers.

You weren't "seeing the future" I want at Round Butte Dam! My salmon future involves restored ecosystems, wild fisheries capable of actually swimming themselves to their natural limits of migration, and no more of these band-aid "techy" efforts that might benefit a single species and forget about the needs of all the others that require free flowing rivers. (You failed to mention that salmon and steelhead cannot migrate past Round Butte on their own and are trapped and transported around the dam in both directions. That's really the future you want to see?! How much diesel fuel to truck each salmon upstream? There's a good climate change model!)

You write,"The implications of climate change on the Fraser, awareness that hydroelectricity may be a critical means of reducing carbon loading" Do you even know about greenhouse gas emissions caused by reservoirs and dam releases, power loss over the power lines running from dams to cities, how much greenhouse gases are produced to build a hydro dam? Guess not.

You then shoot yourself in the foot by writing about the, "ability of dams to regulate river temperature for fish life". You just talked about (correctly) the importance of fish evolving with changing conditions, like they have for millennia. Know you want to promote dam operators "regulating" flows and temperature best for fish? Species evolve in unregulated environments.

I think you should stick with history and let restoration ecologists lead the way towards efforts to restore wild self-sustainable fisheries, based on the best available science. Technology is great for many things, but will never come close to competing with the productivity and resilience of natural ecosystems.

We who care about fish do "need to evolve or die". This includes moving away from unsustainable hatcheries and dams and towards wild fisheries, migratory access to historic habitat, dam removal, and improved water quality and quantity. Destructive hydro-dams are dead!

I encourage you to go to the Elwha River this fall, watch those old dams get removed, see the new water facilities built for the city, visit the dozens of other dams recently removed and their salmon runs rebounding, and follow the revival of these WILD salmon runs over the next few years and reassess how you are "seeing the future".
Hawley Steven
Hawley Steven
Jun 01, 2011 10:16 PM
 Quick comments:
1. There is no consensus that dams are carbon neutral sources of power generation. In fact a team of scientists recommended an IPCC panel study the issue closely before granting any kind of "carbon credits" to dams should some form of global carbon cap and trade program emerge.
2. While Mr. Taylor's book on the history of hatcheries is a worthwhile read, his grasp of the nature and mechanisms of salmon adaptation and evolution is sorely lacking.The vast majority ofcredible science on hatcheries points to a grand, uncontrolled experiment with unknown consequences will be the main result of hatchery proliferation. For example, around the Pacific Rim, some 5 billion hatchery-reared juveniles are released into the ocean every year. The affect this action has on the carrying capacity of rivers and oceans has never been fully considered, much less scientifically studied.
3. A "crappy western economy" can be fixed just as quickly by federal stimulus aimed at dam removal rather than another round of dam building. Moreover, tearing out dams like those on the lower Snake would have long-term ecological and economic benefits. Some 46 studies on the issue have been published; all but one of them forecasts dam removal as a net ecological gain, and an even or better economic bet. The one study that claims it would be a bad idea comes from the Corps, and it has been widely discredited.
Mr. Taylor cites the Bureau of Reclamation's report recommending more dams as if this were some novel new development. BuRec has been recommending more dams every year for more than a century now. But shouldn't a historian be aware of such things?
Matt S.
Matt S. Subscriber
Jun 03, 2011 01:00 PM
I highly recommend that Joseph and others read "Recovering a Lost River- Removing Dams, Rewilding Salmon, and Revitalizing Communities" by Steven Hawley. This is one of the best books ever written about the topic of salmon recovery and the failures of both dams and hatchery practices.

While not specifically about salmon, I also encourage folks to watch the TED video below with chef Dan Barber "How I fell in love with a fish" and consider this important message in the context of salmon, current and harmful aquaculture and hatchery operations, and how to have both thriving ecosystems and abundant and better tasting salmon for us and for the far reaching food web that supports thousands of species across the north Pacific Ocean and North America.