Deepwater Horizon spill threatens more species than legally protected, study finds

"A lot of species in the Gulf of Mexico are going to be damaged by this oil spill but aren't on the U.S. radar screen, although they're threatened globally," says Short, who is a research professor of natural resources and the environment at UNH. Along with lead author Claudio Campagna of the Wildlife Conservation Society and others, Short was a major contributor to the paper, "Gulf of Mexico Oil Blowout Increases Risks to Globally Threatened Species," which appears in the Roundtable section of the May 2011 issue of BioScience.

"It is imperative to understand the global consequences of environmental disasters, as a local perspective underemphasizes the incidence on widely distributed species," says the Wildlife Conservation Society's Campagna. "The IUCN Red List data has an unmatched, so far neglected potential to inform policy decisions at a regional level."

The researchers consulted the extensive species database of the International Union for Conservation of Nature's (IUCN) Red List, which assesses species' global survival status via a rigorous scientific process. They found 53 species with a distribution that overlaps the area of the oil spill that are categorized as critically endangered, endangered, or vulnerable by the IUCN Red List. Of these, only 14 receive legal protection in the United States under the Endangered Species Act, the Migratory Bird Treaty Act, or the Marine Mammal Protection Act.

"There are species that are surely threatened that could be driven to extinction because of this oil spill," says Short.

Among the Red List species that are not protected by U.S. law are the commercially valuable Atlantic bluefin tuna (western stock), 16 species of sharks, and eight corals. Many species are particularly vulnerable because they return to the Gulf of Mexico to spawn, and the oil spill coincided with peak spawning periods. The researchers also write that the whale shark, the largest fish in the world, is uniquely at risk from oil and oil dispersants because of its filter-feeding behavior; its long lifespan and slow reproductive rate compound the threat to its recovery. It is listed as vulnerable on the IUCN Red List but not protected by the Endangered Species Act.

"Threatened species not yet listed in national legislation should nevertheless be the subject of damage assessments, targeted research, and monitoring, as well as recovery efforts when needed," the authors write. The U.S. Natural Resource Damage Assessment, which is the primary legal authority for assessing damages and providing for recovery of coastal and marine species, may not account for injury to these globally threatened species.

Further, the authors advocate that environmental impact assessments conducted for future offshore oil and gas development should incorporate available data on globally threatened species, including species on the IUCN Red List.

"Next time this happens -- and we know there will be a next time -- we need to take this broader list into consideration," says Short.