Opinions, musings, ideas, pearls of wisdom
"Political Science" by Robert Behnke
Excerpted from Trout (the Trout Unlimited magazine), Fall 2004
Submitted by Dougald Scott
"Political Science" by Robert Behnke
Excerpted from Trout (the Trout Unlimited magazine), Fall 2004
Submitted by Dougald Scott
My column in the spring 2004 Trout was titled "The Best Science." It concerned how an ideologically based belief system can distort and selectively use science to support a predetermined, but erroneous, conclusion. When solid science gives way to "political science" anything is possible, as we are now seeing in the proposed changes to the Endangered Species Act listing process.
In my opinion, a pro-development ideology, emanating from the highest levels of government and top agency administrators, is seeking to weaken the ESA (Endangered Species Act) by removing or reducing the protection for 27 groupings (25 listed species and two candidate species) of ESA-protected Pacific salmon and steelhead. The strategy is designed to include hatchery fish with wild fish and resident rainbow trout with steelhead for assessing the status of the ESA protected groups. If this is accomplished, most of the protected salmon and steelhead groups, called evolutionarily significant units (ESUs), could be found to be so abundant that there would be no need for ESA protection.
The proposed changes raise two basic questions: are hatchery fish equivalent to wild fish in "fitness" (survival to returning adults)? And, are resident rainbow trout equivalent to steelhead? If the best science is used to critically determine the answers to these two questions, then the clear response to both is a resounding "no." But if science is ignored, distorted, or manipulated by "political science" any predetermined conclusion is possible.
In 2001, U.S. District Judge Michael Hogan ruled that once an ESU is defined to include both hatchery and wild fish, it can not be subdivided into those separate categories for listing determinations. Both hatchery and wild fish must be considered in any further review of the health of the species. In the years following Hogan's ruling, NOAA set out to update the status of the Pacific salmon and steelhead ESUs with inclusion of hatchery fish and resident rainbow trout in the ESUs. The agency's findings were published in the June 14, 2004, Federal Register. In the report, the agency concedes that the ESA requires them to "make listing determinations based solely on the best scientific and commercial data available." NOAA Fisheries determined that hatchery fish and resident fish would be included in the same ESU with wild fish if "only moderate genetic differences" could be detected.
The "best available scientific data" do not support commingling hatchery and resident fish with wild fish in ESUs. This can be demonstrated and documented by considering two important issues.
The first issue concerns the term "moderate genetic difference" as the basis to include hatchery and resident fish with wild fish. This is an egregious example of "genetic reductionism," an erroneous belief that all significant differences in life history, morphology and ecology can be accurately evaluated from the degree of genetic differentiation detected by genetic analysis (realizing that only a tiny fraction of an organism's DNA is sampled). University of California researcher Jonathan Marks notes in a recent book that there is just a two percent difference in DNA between humans and chimpanzees. This difference could be called " "moderate," but it obviously results in very large and important differences between us and chimps.
Conversely, Galaxias maculatus is a small salmoniform fish found in Australia, New Zealand and the Patagonian region of South America. The South American populations have been isolated from Australian-New Zealand populations for at least 30 million years. However, the fish has continued to fill the same niche throughout its range, and its morphology remains similar enough for it to be classified as a single species. Nonetheless, there are almost twice as many genetic differences between South American and Australian-New Zealand populations as there are between humans and chimpanzees. Clearly, the importance of "moderate" genetic differences varies widely depending on particular circumstances.
This brings me to the second issue: the idea of a "reproductive isolation," which is one of the qualifications required for ESA listing. A particular trout or salmon population must be "substantially reproductively isolated" and an "important component in the evolutionary legacy of a species."
To understand this requirement, consider the steelhead and stream-resident rainbow trout of Oregon's Deschutes River. These two fish have very different life history forms - resident rainbows spend their whole lives within the Deschutes drainage, whereas steelhead may spend half their lives in the North Pacific Ocean - yet modern genetic analysis has failed to find evidence of genetic distinctions between the two fish.
When resident rainbows and steelhead coexist in the same river, occasional mixing during spawning can occur. This slight genetic interchange can blur any genetic differences between steelhead and rainbows and lead to a wrong conclusion about "substantial reproductive isolation." Consequently, other techniques beside genetic analysis are necessary to answer the question on degree of reproductive isolation. Microchemistry of otoliths (tiny bones in the inner ear) can tell if a fish's mother spent time in the ocean or if it lived its whole life in freshwater. When the otoliths of 20 steelhead and 38 resident rainbows from the Deschutes River were examined, all steelhead had steelhead mothers and all rainbows had rainbow mothers. Obviously, the two life history forms are maintaining "substantial reproductive isolation" and, by definition, cannot be considered a single ESU. Rainbows and steelhead cannot coexist without substantial reproductive isolation; otherwise, they would merge into a single population.
Perhaps most frustrating in this debate is the fact that the biologists writing the NOAA document that appeared in the Federal Register did imply that "moderate genetic differences" might be important. For steelhead, they expressed the fear that the anadromous (steelhead) component of an ESU might become extinct if not given ESA protection - in other words, they doubted that the resident rainbow trout component of the ESU could produce steelhead. Clearly, they acknowledged a genetic basis for anadromous and resident behavior. The NOAA biologists concluded that protection for all ESUs should be continued, thus denying the first spate of petitions to delist 15 of them. This is laudable, but the politically directed policy of including hatchery fish and resident populations with wild fish for determining the status of an ESU remains ominous. On this critical issue, a reliance on "political science" could have devastating consequences for Pacific salmon and steelhead.