Author: Damien M. Schiff
The Ninth Circuit this week issued another decision in the longrunning dispute over whether and how to protect populations of salmon and related fish under the Endangered Species Act. In Modesto Irrigation District v. Gutierrez, the plaintiffs challenged the National Marine Fisheries Service's decision not to group California steelhead (an anadromous salmonid) and rainbow trout into the same ESA-protected population, as the agency once had. (The obvious effect of the agency's separating the populations was to make each new subpopulation more likely to be listed, because fewer numbers generally translates to greater risk to a population's viability).
The plaintiffs challenged the Service's decision on two grounds. One, the Service, when listing distinct population segments of species (as the Service had done here), must include in that population all individual members of the species that can interbreed. Second, the Service erred by not sufficiently explaining why it chose to list these fish populations under the Joint Distinct Population Segment Policy (which the National Marine Fisheries Service shares with the United States Fish and Wildlife Service), rather than the Evolutionarily Significant Unit Policy, which is the standard policy used when listing salmonid populations.
The Ninth Circuit rejected both arguments. First, the Court found that the ESA was ambiguous on the interbreeding requirement, and concluded that the Service's interpretation—interbreeding is a necessary but not sufficient condition to being included within a DPS—was reasonable. (For what it's worth, this conclusion seems correct to me. After all, the necessary condition for two individuals to be considered part of the same species is that they be capable of interbreeding. But when deciding whether to include two individuals within the same DPS, one is already dealing with individuals within the same species. Thus, if interbreeding were the only condition for DPS status, then DPS status would be meaningless, because one could never have a DPS smaller than then entire species population).
Second, the Court found that the Service's decision to use the DPS policy, as opposed to the ESU policy, was reasonable: the Service had made clear that it was aware of the change in practice, and further gave good reasons as to why it was changing course, in particular new scientific evidence showing that rainbow trout probably could not reestablish a steelhead population, as well as other behavioral data supporting the conclusion that rainbow trout should be treated, for conservation purposes, differently from steelhead.
In the district court, this case had been consolidated with California State Grange v. National Marine Fisheries Service, in which PLF attorneys represented several parties challenging the Service's salmonid population listings on the ground that they impermissibly distinguished between the naturally spawning and hatchery-raised components of each listed population. The court ruled against us on that claim, and we did not appeal. Shortly before that case was decided, the Ninth Circuit ruled in another PLF case, Trout Unlimited v. Lohn, that the Service's Hatchery Listing Policy, under which hatchery-raised salmonids were looked to only to the extent that they could support the naturally spawning component of the same population, was a legitimate interpretation of the ESA's DPS power.