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ESA Evolves With Steelhead
Just how dramatically an innovative effort to save a high-end game fish will redefine the debate over endangered species will be seen when the Endangered Species Act comes up for a sorely overdue reauthorization. In the meantime, a good measure of the debate over the upcoming listing of steelhead trout stems from the fact it is almost indistinguishable from the mundane but beautiful rainbow trout, a fish which proliferates in lakes and water impoundments. Often the steelhead share the same territory with rainbows. But the steelhead receives a genetic call to move out to sea. Because of the steelhead's vast range, which stretches from Siberia's Kamchatka Peninsula to Baja California, and its remarkable diversity of behavior and habitats, biologists have had to come up with a complex proposal for listing, protecting and restoring the fish.
"There's nothing comparable to this listing," says Mark Capelli, an analyst for the California Coastal Commission. "This is the most sophisticated, complicated use of the ESA since its inception. There's more science behind this and there are more people involved."
The steelhead trout listing proposal, expected to be finalized this August, reflects the genetics, politics and biology of a complex coastal species that ranges from fresh mountain creeks to the salty ocean deep. In are remarkable essay, John Krist of the Ventura County Star describes how steelhead and other members of the salmonid family possess "an onboard desalinization plant" that allows them to drink salt water as they reach the sea, shutting down their kidneys and activating special cells in the gills to filter out sodium and chloride.
"It's an elaborate, elegant and remarkable adaptive mechanism," he writes," offering the seagoing salmon and trout two distinct survival advantages: By leaving the nutrient poor environment of small, high-altitude streams for the richness of the sea, the migratory fish obtain access to an abundant food source. And by escaping the confines of its birthplace, it is free to colonize new river systems - entering from the sea - where competition may be less fierce."
Adaptability could be considered the defining quality of steelhead, paradoxical as that may sound. For fishermen, steelhead and rainbows are quite different. Steelhead grow muscular and tough on their journey to the sea. They are in an entirely different weight class, coming in at around 8-10 pounds instead of the rainbow's two or three.
For biologists, steelhead are what is called an umbrella species, which means that if steelhead are protected, then other species generally receive protection, too. This is because the steelhead's range exceeds that of other anadromous fish. They possess the ability to migrate further upstream than most chinook salmon species and can tolerate a greater range of temperatures. Runs vary across a wider spectrum of the year, which allows them to select from a variety of niches. And steelhead don't always follow the bumper sticker advice "Spawn and Die." Up to a third return to the sea after spawning.
In political terms, the steelhead's adaptability could cause even more clashes with commerce than the listing of various salmon species. The salmon's range stops around Monterey Bay, while steelhead run smack into the tangled plumbing of southern California, probably the most heavily managed water supply in the country.
To make things even gnarlier, a geneticist named Jennifer Nielsen came up with startling results after receiving NASA funding to look at what the steelhead's genetic bio-diversity could reveal about global climate change. Nielsen found that genetic diversity was greater in the southern population of steelhead than in the central and northern populations. Because Nielsen was not looking at adaptation but at genetic drift, the changes in genomes that take place randomly over time, this meant that the southern steelhead had been around longer. To Nielsen, it also suggested that, contrary to received scientific opinion at the time, steelhead migrated south as the Ice Age progressed, only returning to the Pacific Coast after the ice caps melted.
"The Sea of Cortez is well-documented as a base or divergence point for an awful lot of fishes during the Pleistocene," Nielsen says. "I still agree that steelhead (which until 1989 or so were once erroneously thought to be offshoots of Atlantic salmon) are part of the Pacific salmon family but there's no reason they couldn't have had a separate and different path during the Pleistocene with a southern refugia."
Nielsen is continuing to research steelhead, including a study of correlations between southern steelhead and southwestern species of Gila trout, Apache trout and Mexican trout, which are found in inland areas surrounding the Sea of Cortez.
For political purposes, though, Nielsen's initial research, completed in 1994, was enough to help propel endangered species protection into a new era. The listing proposal for steelhead reflects the diversity of the fish by utilizing a new concept called "evolutionarily significant units" or ESUs. Robin Waples, head of conservation biology for the National Marine Fisheries Service (NMFS) at the Northwest Fisheries Science Center in Seattle, is credited with developing this concept.
According to Waples, the idea grew out of a controversial provision in the Endangered Species Act that protects distinct vertebrate populations - an even finer distinction than sub-species. This provision was almost dropped from the Endangered Species Act in 1979. Instead of jettisoning it, Congress instructed the Secretaries of Interior and Commerce to apply the provision sparingly.
"There was a lot of uncertainty over what qualified as a population under the Endangered Species Act," Waples says. "Species can be vague. Sub-species can be even vaguer. For populations, that's a whole order of magnitude more vague.
"Some guy can say, 'There's 50 steelhead on my grandfather's farm. They've been there for 50 years. They must be a distinct population.' Other people say salmon have been radiating out since the Ice Age. Most people are in between. But U.S. Fish & Wildlife, which has made most of the determinations regarding distinct populations under the ESA, didn't have consistent guidelines. Sometimes they turned down populations that seemed pretty distinct."
In 1990, Fish & Wildlife held a workshop to formulate population guidelines. The term "evolutionarily significant unit" was bandied about, but nobody formalized the definition or developed firm guidelines after the conference. Waples decided to go ahead and develop the concept to help solve the problem of protecting anadromous fish. He used state-of-the-art genetic research, ecological science, and old-fashioned game warden expertise to put together a workable definition of distinct populations. NMFS began applying this definition in 1991 to petitions for listing various Pacific Coast Chinook, Coho and Sokeye salmon populations. But Waples says the steelhead application is the most far-ranging - covering a lot more of California - and complex yet. Nielsen's research, which focused on extremely subtle genetic distinctions that determined steelhead's location over thousands of years, was only a part of what Waples used in his attempt to provide a framework for dealing with steelhead.
"What we're trying to identify is groups of populations that are important in an evolutionary sense, but it's not tied to any genetic method," says Waples. "There's a lot of information that's indirect, hard to quantify, but nevertheless, gives us a lot of insight."
Run timing, life history differences, spawning times, fish size and shape, age structure, environment and ecology all play roles in deciding what constitutes an ESU. Some critics charge that politics have played a role as well. Peter Moyle, professor of fisheries at the University of California at Davis, criticized the use of the whole concept of ESUs as a bow to political pressure from opponents of the ESA.
"This ESU business is a real mess," Moyle told a reporter for Western Outdoors magazine. "NMFS was under a lot of pressure to be consistent when dealing with salmonid stocks. There was Congressional pressure not to list every little population."
Nevertheless, Moyle says there are several populations that can clearly be considered as distinct, including fish on the upper Sacramento, on Mill and Deer Creeks, and south of Point Conception.
Waples defends the ESU concept as an alternative to saving every stream and pond where steelhead can be found. This would include "hundreds or thousands of populations," says Waples, who called such an undertaking a "nightmare," and "completely unworkable under the ESA."
"We're trying to reach some sort of balance," he says. "If we save ESUs that are pretty good chunks of genetic diversity then the species will be viable as a whole."
Diane Valantine of the Oregon Natural Resources Council, a co-plaintiff in a 1994 lawsuit to force NMFS to meet deadlines for listing steelhead, says she isn't interested in quibbling about ESUs. With 95 percent of steelhead habitat in the Central Valley gone and serious problems in many other parts of its range, she's more concerned that the agency will ask for a six-month extension of the listing deadline. Not long ago, NMFS gave itself a six-month extension for presenting its plan to protect the endangered Coho salmon.
"It has taken litigation at every turn to make these things happen," says Valantine. "We look to the Clinton administration for that. They're really dropping the ball on salmon protection.
"You have to wonder what they're thinking," Valantine adds. "Protecting salmon and steelhead is a wonderful opportunity for the federal government to show how the ESA works with states and private entities, and how it helps protect jobs and communities. If they're trying to show ESA successes, this is not one to run away from. There are good things going on at the state level to augment federal actions."
The Coastal Commission's Capelli says that the Clinton administration may feel pressure to reauthorize the act because the longer a program goes without formal reauthorization, the lower it is on the funding priority list. As the act has languished without reauthorization, funding levels have dropped below what they were in the Bush administration. History has shown that without adequate funding for implementation, the ESA has a marked tendency to irritate landowners. The downward spiral from there is obvious.
The effort to save steelhead may be new, but the problems with making it a reality are old. As citizen comments pour in over the next months, steelhead biologists will have a chance to see if, once again, in the words of geneticist Jennifer Nielsen, "the voice of the animal gets lost in the politics."
Contacts:Mark Capelli (805) 641-0142; Jennifer Nielsen (408) 655-6233; Diane Valantine (503) 283-6343; and Robin Waples (206) 860-3254
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