The Fish and Wildlife Service (“Service”) announced yesterday that the Sacramento splittail, a fish endemic to California’s Central Valley, does not warrant protection under the Endangered Species Act, stating that the best available science shows no recent decline in the overall abundance of the species nor threats that rise to the level of being significant to the splittail at the population level.

This decision marks the conclusion of a seven year controversy between politicians and scientists that began when the Service removed the fish from the threatened species list, overruling Service biologists recommendation to the contrary.  Julie MacDonald, a former Deputy Assistant Secretary in the Department of the Interior, was heavily involved in delisting the Sacramento splittail.  Later it was found that MacDonald owned an 80-acre farm in the splittail’s habitat, which has a range that centers on the San Francisco Estuary (see earlier post).

While biologists favored listing the Sacramento splittail as threatened in 2003, counting populations of the fish by using straight surveys, scientists now say that natural fluctuations of population numbers demonstrate a pattern of successful spawning during wet years followed by reduced spawning during dry years.  Further, the Service reports that a number of habitat restoration actions benefiting the splittail are underway including species enhancement conservation measures, creation of new seasonal floodplains, and new state fishing regulations limiting the take of splittail. The Sacramento splittail is also one of the species targeted for protection under the proposed multi-agency Bay Delta Conservation Plan.

Still, environmental groups are not happy with this decision, claiming the Service’s conclusions are “outrageous” and scientifically unjustified.  Some argue that the Service’s decision regarding the species is politically charged: “Including it on the list would add a layer of complication to an already dizzying set of issues in the Delta, where a biological collapse is putting pressure on water supplies statewide,” says Mike Taugher with the Contra Costa Times.  The Center for Biological Diversity has indicated it plans to take the Service to court to press for a reversal of the decision.

The Service’s finding is expected to be published in the Federal Register on October 7, 2010.