Appeal from the United States District Court for the Eastern District of California. Oliver W. Wanger, District Judge, Presiding. D.C. No. 1:06-cv-00453-OWW-DLB .
The opinion of the court was delivered by: Schroeder, Circuit Judge
Argued and Submitted December 11, 2009 -- San Francisco, California.
Before: Mary M. Schroeder and Consuelo M. Callahan, Circuit Judges, and Barbara M. Lynn, District Judge.*fn1
This Endangered Species Act ("ESA") case is a challenge to the decision of the National Marine Fisheries Service ("NMFS") to list the steelhead, a type of Pacific salmon, as a threatened species in California's Central Valley. In listing the steelhead, NMFS defined it as a distinct species under the ESA, separate from rainbow trout, another type of Pacific salmon that breeds with and looks like the steelhead. The separate listing was a departure from the prior NMFS policy of classifying interbreeding Pacific salmon as a single species.
Plaintiffs are irrigation districts in California's Central Valley whose operations are impeded by the listing. They contend that the listing violated the ESA because steelhead and rainbow trout interbreed, and the statute therefore requires NMFS to treat them as a single species. Plaintiffs also contend that NMFS violated the Administrative Procedure Act ("APA") by failing adequately to explain its decision to adopt a new policy for classifying the fish. We agree with the district court that under the ESA, interbreeding is not alone determinative of whether organisms must be classified alike where, as here, they develop and behave differently. We also find that NMFS' explanation for its change of policy satisfies the standards set forth in the Supreme Court's recent decision in F.C.C. v. Fox Television Stations, Inc., 129 S.Ct. 1800 (2009). We therefore affirm.
THE STEELHEAD AND RAINBOW TROUT
This case turns upon the distinctions between the steelhead and rainbow trout, types of Pacific salmon that comprise the Oncorhyncus mykiss ("O. mykiss") species as scientifically defined. The fish are born in fresh water, but the steelhead migrate to the ocean anywhere from hours to years after their birth. To transition from fresh water to salt water, steelhead undergo a "smolt" stage, and then after one to five years in the sea, return to the original stream to spawn. Because of their migration pattern, steelhead are known as the anadromous form of O. mykiss. The rainbow trout, on the other hand, remain in fresh water their entire lives and are commonly known as the resident form of the O. mykiss species.
While the two fish grow to differing sizes as adults and have different predators and prey, they do interbreed to some extent, and the offspring can take on the form of either. An excess of steelhead can regenerate the population of rainbow trout, but the reverse does not seem to be the case. All parties agreed in the district court and before us that the steelhead population is in decline in the Central Valley of California.
This unique biology of O. mykiss has complicated government regulation of the species. In 1974, the United States Fish and Wildlife Service ("FWS") and NMFS entered into a memorandum of understanding defining their respective juris- dictions under the ESA. FWS has jurisdiction over predominantly freshwater fish including rainbow trout, and NMFS has jurisdiction over ocean dwellers, including steelhead. This concurrent jurisdiction has required the agencies to work together in classifying O. mykiss under the ESA.
STATUTORY AND REGULATORY HISTORY
The ESA defines the term "species" to "include[ ] any sub-species of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature." 16 U.S.C. § 1532(16). Congress added the term "distinct population segment" ("DPS") to the definition of species in 1978 so that agencies could "provide different levels of protection to different populations of the same species." Nat'l Ass'n of Home Builders v. Norton, 340 F.3d 835, 842 (9th Cir. 2003). Congress did not define DPS, nor is the term used in the scientific community. As a result of this limited guidance from Congress, NMFS has struggled for two decades over how to apply the term DPS with respect to steelhead and rainbow trout.
NMFS' first attempt at defining a DPS in this context occurred in 1991 when the agency adopted a policy designed specifically for classifying Pacific salmon such as O. mykiss. See Policy on Applying the Definition of Species Under the Endangered Species Act to Pacific Salmon, 56 Fed. Reg. 58,612 (Nov. 20, 1991) ("ESU Policy"). This policy did not use the statutory term DPS, but instead created another new term called the evolutionary significant unit ("ESU"). NMFS also determined, however, that an ESU was the functional equivalent of a DPS. See id. Under the ESU Policy, a salmon stock had to satisfy two main criteria before NMFS could place the stock in a distinct ESU:
(1) It must be substantially reproductively isolated from other nonspecific population units; and
(2) [I]t must represent an important component in the evolutionary legacy of the species.
In 1996, in conjunction with FWS, NMFS promulgated a more general policy defining the ESA's operative concept of DPS, a policy that would apply to all animal, bird and fish species. See Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the Endangered Species Act, 61 Fed. Reg. 4,722 (Feb. 7, 1996) ("DPS Policy"). The DPS Policy, like the ESU Policy, required NMFS to examine multiple factors in determining whether an organism qualified as a DPS. See 61 Fed. Reg. at 4,725. There was, however, a key difference between the ESU and DPS Policies. Under the ESU Policy, a type of Pacific salmon had to be "substantially reproductively isolated" from other salmon stock before it could be classified in its own ESU, whereas, under the DPS Policy, an organism could be placed its own DPS so long as it was "markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors." See Endangered and Threatened Species: Request for Comment on Alternative Approach to Delineating 10 Evolutionary Significant Units of West Coast Oncorhynchus mykiss, 70 Fed. Reg. 67,130, 67,131 (Nov. 4, 2005) (describing the history of the policies). NMFS and FWS concluded in 1996 that the ESU Policy was, despite this difference, "consistent with" the DPS Policy and that both agencies would continue to apply the ESU Policy to Pacific salmon, and apply the DPS Policy to all other organisms. See 61 Fed. Reg. at 4,722.
When NMFS applied the ESU Policy to Pacific salmon in 1997, it determined that interbreeding steelhead and rainbow trout populations should be classified in the same ESU because they were not "substantially reproductively isolated." See Endangered and Threatened Species: Listing of Several Evolutionary Significant Units (ESUs) of West Coast Steel- head, 62 Fed. Reg. 43,937, 43,941 (Aug. 18, 1997). NMFS noted, however, that "conclusive evidence d[id] not yet exist regarding the relationship of resident and anadromous O. mykiss," which in most respects was "poorly understood." See id. at 43,938, 43,941.
Although NMFS and FWS agreed in 1997 that interbreeding populations of steelhead and rainbow trout should be placed in the same ESU, there was some dispute about how to protect threatened O. mykiss populations. In many regions the steelhead population was declining and NMFS desired to list those populations as threatened or endangered. FWS, however, opposed any listing that would have protected the rainbow trout, having determined that its populations were in no way threatened. See id. at 43,941. FWS thus did not want to list any ESU containing both steelhead and rainbow trout, even where the steelhead population within that ESU was declining.
NMFS addressed FWS' concern by deciding that when an ESU contained both steelhead and rainbow trout, NMFS would list only the steelhead population within that ESU as threatened or endangered. See 70 Fed. Reg. at 67,130. By listing subdivisions of an ESU, NMFS was able to protect declining steelhead populations while acceding to FWS' desire not to list rainbow trout.
Such subdivision listings were challenged in court, however. In Alsea Valley Alliance v. Evans, 161 F. Supp. 2d 1154, 1161-64 (D. Or. 2001), the court held that the ESA requires that agencies list (or not list) entire DPSs/ESUs, thus precluding any listings below the ESU/DPS level. The court in Alsea found it was contrary to the ESA for NMFS to list only the steelhead population of an ESU containing both steelhead and rainbow trout. NMFS therefore had to revisit all of its prior steelhead listings.
In 2004, NMFS promulgated a number of new listings to conform with the Alsea decision. Relevant to this litigation, NMFS defined the California Central Valley O. mykiss ESU as comprising all steelhead and rainbow trout that "cooccur[red]" below impassible barriers. See Endangered and Threatened Species: Proposed Listing Determinations for 27 ESUs of West Coast Salmonids, 69 ...