WASHINGTON (CN) – The upper Missouri River population of Arctic grayling, a member of the salmon family, is endangered by large dams that obstruct its migrations and spawning, according to the U.S. Fish and Wildlife Service.
The barriers have created a genetically isolated population that does not have the diversity to thrive, the agency stated in its decision to list the fish as threatened or endangered under the Endangered Species Act, once it has the funds to do so.
Although the agency estimates that 95 percent of the species’ range has been curtailed in the last 100 years, and other isolated populations in Michigan and Montana have gone extinct, it noted that protecting the fish is currently precluded by higher order listing decisions.
The efforts to conserve the isolated populations of the central U.S. have a long and convoluted history beginning with a status review in 1982 that determined that insufficient data existed as to the population and genetic relation of the species to other populations to support a listing decision.
In 1991 the Biodiversity Legal Foundation requested listing the upper Missouri River Arctic grayling as endangered, and in 1994 the agency concluded listing was warranted but precluded by higher priority listings. Legal challenges to the “warranted but precluded” finding resulted in the agency finding in 2007 that listing was not warranted because the upper Missouri River populations were not a species or subspecies under the Endangered Species Act, and the fish was removed from the candidate list of species for protection.
Environmental groups challenged that decision, and as the Bush administration, which was notorious among environmental groups for overturning previous listing recommendations, was replaced by the Obama administration, the agency reached a settlement agreement in 2009 to initiate another 12-month status review, which resulted in the current listing decision.
The “warranted but precluded” status means that the agency does not have enough money left in its current fiscal year budget allocation to list and prepare conservation plans for all of the species it has previously determined to list, plus new listings. Species placed in this limbo are reviewed during the preparation of the next year’s budget, and may, depending on the priority of other listing decisions make it to listed status in the following year.