Editor's Note: Ensuring the survival of migratory fish that spawn up stream is an issue of increasing concern. Yesterday (3/16) NOAA's National Marine Fisheries Service announced that nine species of salmon in the Puget Sound watershed would be listed as endangered or threatened. Dam operations, combining with heavy fishing pressure, are making such fish increasingly candidates for listing on threatened or endangered lists. While such listings of endangered salmon runs in the Pacific Northwest have generated a great deal of attention, the issue is also being faced in the Great Lakes region. NOAA Sea Grant research is showing that changes in water flow management and dam water draw operations could provide significant payoffs.
Fish respond to natural water flow in Manistee River; economic benefits could follow
STUDY SHOWS WATER FLOW MANAGEMENT IN MICHIGAN AIDING IN SALMON, TROUT RECOVERY
FOR IMMEDIATE RELEASE March 17, 1999
CONTACT FOR MORE INFORMATION: Edward S. Rutherford, Assistant Research Scientist, Michigan Sea Grant, University of Michigan School of Natural Resources and Environment, (O) 734- 663-3554, [email protected]
Michael Moore, Associate Professor of Natural Resource and Environmental Economics Michigan Sea Grant, University of Michigan School of Natural Resources and Environment (O) 734- 647-4337, E-mail: [email protected]
Joyce Jakubiak, Editor, Michigan Sea Grant, University of Michigan, (O) 734- 647-0766, E-Mail: [email protected]
Ben Sherman, National Sea Grant Media Relations (O) 202-662-7095, E-Mail: [email protected]
ANN ARBOR, MI. For 80 years, water flow in western Michigan's Manistee River fluctuated dramatically each day --- ranging from 10-year floods to drought conditions. The variation was caused by hydropower dam operations known as peak flow management, a practice that permits the periodic release of large amounts of water. Studies have shown that such erratic flows can cause aquatic organisms to alternately become stranded or swept downstream, negatively impacting the fish that rely on them for food.
On the Manistee, a major Lake Michigan tributary, relief came in 1989. Peak flow management was abandoned in favor of a less disruptive practice known as run-of-river flow management. Water was allowed to flow naturally through the Tippy and Hodenpyl dams as a result of terms specified in new hydropower licenses. Today, a decade later, the change is beginning to pay off. Researchers at the University of Michigan and Michigan State University, funded in part by NOAA's Michigan Sea Grant Program, have found that survival of young chinook salmon in the Manistee has increased dramatically since the late 1980s in response to a stable water flow.
"Natural reproduction is incredible now," says Sea Grant and University of Michigan fisheries biologist Ed Rutherford. "It's gone from virtually nothing to approximately 700,000 smolts annually."
Still, the switch to run-of-river flows hasn't solved everything. The researchers found that although steelhead reproduction has also increased, the fish had a lower survival rate than that of young chinook. Rutherford suspects warm water temperatures may be the reason. Steelhead spawn and rear in the tailwater of dams, he explains, where summer water temperatures may be too warm. Many top-draw dams pull the warmer surface water from above the dam, which then flows downstream. Because steelheads remain in the stream longer than salmon, Rutherford suspects they may be affected to a greater degree by warm water temperatures.
Using electroshocking sampling techniques, Rutherford and colleagues measured the abundance and diversity of fish in the Manistee over a two-year period. They also used smolt traps to monitor the smolt run and examined the scales and vertebra of adult fish to distinguish wild salmon from those reared in hatcheries. (Salmon reared in hatcheries make up the majority of the salmon caught in Lake Michigan.) The researchers estimate that the greater numbers of chinook and steelhead wild smolts surviving in the Manistee represent an 8.6 and 6.4 percent increase, respectively, in potential harvest available to recreational anglers, as compared to the harvest during peak flow regimes in the late 1980s.
The Bottom Line
The increase in chinook and steelhead is crucial information for the next phase of the project to be completed this year. University of Michigan economist Michael Moore, and colleagues Michigan State University agricultural economists Frank Lupi and John Hoehn, will use a state-of-the-art economic model of recreational fishing in Michigan to translate the improved ecological changes into the dollars and cents of economic benefits.
They already know one thing: sportfishing is big business. Chinook and steelhead are two of five species of fish that make up the salmonids group. Spending associated with recreational fishing for salmonids in the Great Lakes is estimated to contribute $1 billion per year to the economy, according to a Great Lakes Fisheries Commission Special Economic Report. However, estimating the economic benefit of improvements to the sport fishery can be tricky.
For instance, in the process of relicensing hydropower dams, the Federal Energy Regulatory Commission (FERC) was required in 1986 to consider the benefits of fish and wildlife protection, recreational opportunities, and preservation of environmental quality. The problem, explains Moore, is that FERC's method of analysis has historically characterized costs and benefits only in terms of profits and losses to the companies that own the dams. As part of the research, Moore and colleagues reviewed FERC's analytical procedures.
"One of the things we found," says Moore, "is that FERC collects very little information on benefits of improved ecosystem function and recreational opportunities. They do an unbalanced analysis."
Incorporating comprehensive data on costs and benefits can have tangible effects. For example, explained Moore, each hydropower license contains a series of operating conditions. Specific operational changes such as adding fish ladders or changing to run-of-river flow scan be required if potential benefits are first recognized and quantified. On the Manistee, new data on steelhead raises the question of altering top-draw dam operations to bottom-draw to provide steelhead with cooler water. In essence, Moore said, a full accounting of the economic benefits might provide a basis for recommending operational changes.
The economic model will balance these benefits against the costs of run-of-river flows, which are measured in terms of lost hydropower revenues from the change in flow management.
In the coming years, the economic approach may be relevant to more than just the Manistee River as numerous dams in the Great Lakes basin come up for relicensing.
Over the next two years, the researchers will continue their work on the Au Sable and Muskegon rivers in order to create a scientific evaluation framework that is generally applicable to Great Lakes tributaries. From that work may just come a model case study for other regions struggling with the conflicting goals behind sustainable ecosystem management.
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-- Ben Sherman, Media Relations Coordinator National Sea Grant College Program 841 National Press Building 529 14th Street NW Washington D.C. 20045-2277 Phone: 202-662-7095 Fax: 202-662-7093 E-Mail: [email protected] WWW News Media Center Site: http://www.mdsg.umd.edu/seagrantmediacenter/
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