The Concept of a Salmon "Species"

Why would NMFS list the sockeye population in a single lake as endangered, when sockeye are plentiful? Few people realize that the Endangered Species Act does not protect just "species", but also subspecies, and even sub-subspecies, or "distinct population segments".

A "species" is something you can look up; a Latin name describing a specific taxonomic group of animals. As Harvard Professor Stephen Jay Gould has explained, the “category of species has a special status in the taxonomic hierarchy” because “each species represents a ‘real’ unit in nature”.38 A species is simply a population of actually or potentially interbreeding organisms sharing a common gene pool.

Professor Gould notes that both above the species level (taxon, genus, etc.) and below it (subspecies, distinct population segments, etc.), the designations are inherently arbitrary. The boundaries of a subspecies can never be fixed and definite, because by definition the members of a subspecies can interbreed with different subspecies, potentially forming other subspecies. According to him, “[m]any biologists are now arguing that it is not only inconvenient, but downright misleading, to impose a formal nomenclature on the dynamic patterns of variability that we observe in nature”.39

The endangered Snake River spring/summer and fall chinook salmon are identified as "distinct population segments" of the species Oncorhynchus tshawytscha—chinook salmon. In the case of endangered Snake River sockeye salmon, the species is Onchorhynchus nerka—sockeye salmon. The world is swimming in chinook and sockeye salmon. There are probably more than a thousand populations of chinook salmon scattered in a ring around the Northern Pacific from California, Oregon, Washington, British Columbia, Alaska and Siberia, and transplanted populations in New Zealand and (perhaps) Chile. Any pair of these salmon can successfully interbreed, even if they are from populations thousands of miles apart.

The endangered and non-endangered Snake River chinook salmon are identical to the naked eye. In fact, it is difficult to tell the stocks apart even with expensive, high-tech genetic testing. NMFS relies on "gel electrophoresis" to identify variations in the frequency of particular salmon genes at particular gene locations.

There are some subtle visual differences in appearance between upriver and downriver chinook salmon stocks in the Columbia River Basin. So while you can't really tell the Snake River salmon apart from the other upriver stocks (like the abundant mid-Columbia stocks), you can tell them apart from lower river stocks. But the visual differences are far less than, for example, differences among different breeds of roses, rabbits or cows. The only way to be relatively sure of what population a salmon comes from is by watching where it returns to spawn; since salmon stray, we can never be sure.

Yet catching a wild chinook salmon in some parts of the Snake River Basin can constitute a federal crime. Catching one in a gillnet in the lower Columbia River is authorized and supported by the National Marine Fisheries Service. Why is this legal? Because when the gillnet is pulled into the boat, with the drowned salmon hanging from it, there is no way to distinguish the "endangered" salmon from the common ones.

In the case of Snake River spring chinook, state and tribal fishery agencies have urged protection of each and every one of 38 subpopulations of this tiny "distinct population segment" of the chinook salmon population. There is no unique genetic material in any of these populations; only the frequency of genes common to all 38 populations varies.40 And there is no evidence that different frequencies of genes have any measurable effect on the salmon's ability to survive.

The Endangered Species Act allows the bureaucrats to try to protect, as "endangered species", populations of animals identical but for differing gene frequencies. Yet, as the National Research Council has explained, “individual local breeding populations of salmon are expected to have a limited time of persistence on an evolutionary time scale” because the salmon consist of a “metapopulation” in constant “balance between extinction and recolonization of local breeding populations”.41 Trying to freeze one particular pattern of local breeding populations in place is like trying to stop the tide.

When the fact that Snake River salmon are separated into a number of populations that can re-establish each other is taken into account in assessing the likelihood of extinction, the results are striking. Dr. John Emlen of the Northwest Biological Science Center has prepared the only analysis I know of. His conclusion: “the model projections indicate a virtually certain persistence of Snake River spring chinook over the next 100 years”.42 While Dr. Emlen warns that models can be misleading, his analysis flies in the face of all conventional wisdom on salmon. The fishery agencies have responded by ignoring his work entirely.

This is not to say that evolution, or metapopulation dynamics, is an excuse for not protecting salmon. Some biologists believe that mankind has produced a great “acceleration” of evolution. This in turn is “an indication of what must have happened again and again in geological history whenever any species or group of species became so ecologically dominant as greatly to upset the habitats of their own times”.43 Short of depopulating the Pacific Northwest, that ecological dominance is not going to disappear.

Moreover, those who claim that the rate of extinctions is at an all time high suffer from what Gregg Easterbrook has called the “Fly Corpse Factor. If species were dropping like flies, the corpses should be piling up by now. Instead species corpses turn out to be exceedingly difficult to locate.”44 He points out that because of the Spotted Owl Hoax, the Northwest forests are among the best-studied ecologies. Yet researchers have not uncovered “a single actual extinction, which seems revealing given that every graduate student involved in a Northwest forest field study is acutely aware that documenting a species loss would make his or her academic career”.45

While protecting genetic diversity is important, it is worth remembering that

“[s]cientists now believe Earth’s ecosphere has become progressively more diverse, playing host to a greater range of species and gene lines as the ages have passed. Edward O. Wilson of Harvard University, a leading contemporary biologist, thinks that at present global genetic diversity is the highest ever, with perhaps as many as 100 million species walking the earth.”46

And if each species had a thousand “distinct population units”, like chinook salmon, then there would be 100 billion distinct population units on the earth.

Mankind is gifted with the choice of how to influence the environment, and the opportunity to choose how its dominance will affect other species. As the biologists who studied Darwin’s finches concluded: “Species don’t stand still. You can’t ‘preserve’ a species.”47 The historic hundred pound salmon of the Columbia River are gone forever unless we use technology to bring them back. By making the right choices in salmon recovery, we may be able to exercise our dominance in a way that helps to bring back many salmon, even if they are not pristine wild salmon.

38 S. Gould, Ever Since Darwin: Reflections in Natural History 232 (W.W. Norton 1992).

39 Id.. at 233.

40 R. Turner, "Conservation Biology", Wana Chinook Tymoo, Issue One, 1996, at 33 (CRITFC).

41 NRC, Upstream at 135 (Prepub. ed.).

42 J. Emlen, “Population Viability of the Snake River Chinook Salmon (Onchorynchus tshawytscha), at 14.

43 E. Anderson & G. Stebbins, “Hybridization as an Evolutionary Stimulus”, quoted in J. Weiner, The Beak of the Finch 244.

44 G. Easterbrook, A Moment on the Earth 558.

45 Id. at 559.

46 G. Easterbrook, A Moment on the Earth 36.

47 R. Grant & P. Grant, Evolutionary Dynamics of a Natural Population, quoted in J. Weiner, The Beak of the Finch 250.

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