The loggerhead sea turtle is one of five species of sea turtles that make their home among the sandy coastal habitat along the shores from Texas to Virginia. As the world’s largest hard shell turtle, the loggerhead can get up to an astounding 350 pounds - quite a feat for a turtle starting as a tiny hatchling no larger than 2 inches long and weighing around half a pound. While each year thousands of these loggerhead hatchlings make their way toward the open ocean, populations of loggerhead turtles have been on the decline, and in 1978, the loggerhead was listed as threatened under the Endangered Species Act (ESA). And the loggerhead is not alone - as of 2016, all five species of sea turtles in the United States are listed as threatened or endangered.

Listing a species like the loggerhead as threatened or endangered isn’t enough to achieve the ESA’s goals of extinction prevention and recovery. Congress recognized the need to develop and implement recovery plans to guide how we halt and reverse threats so that species are protected for the long-term. For the loggerheads and other sea turtles, these plans can include addressing threats like increased beach development and fisheries bycatch.

Though most species get a single set of recovery actions in their recovery plans, others might require more specialized actions for different sections of the species’ population. In the Atlantic, loggerheads range from the Caribbean up to the coast of Virginia, with variation in nesting habitat, predators, and levels of human disturbance. “Recovery units” are a tool that can reflect this variety - they are subunits of a species’ range, each of which must be recovered before an entire species can be considered recovered. By using this approach, tailored recovery goals can be set for each unit, allowing biologists to measure their contribution toward recovery of the loggerhead population.

In new research, scientists at Defenders and collaborators found 49 species have recovery units designated, including the loggerhead. They also found that there is very little information on how recovery units have been developed and used during the implementation of the ESA.

“We know recovery units are rarely used, but they are an intriguing ESA tool because of the fact that they already exist under current ESA regulations - no need to pass new legislation or re-write regulations. We found that there was a clear pattern in which species received recovery units: species with large ranges that had a relatively high amount of genetic research. When we compared species with and without recovery units, we saw that species with recovery units improved more often than those without. This finding suggested that species with recovery units designated fared better - on average - than those that didn’t.”

~ Dr. Michael Evans, Senior Conservation Data Scientist at CCI and lead researcher for the study

In addition to making the paper public, the data were shared with the Fish and Wildlife Service to include in official databases to improve decision-making around recovery units. While not all species may benefit from the use of recovery units, highlighting where this tool has been effective in the past can help biologists understand where it can be applied for other listed species. Ultimately, recovery units are one tool in the toolbox to help conserve and recover species. From reptiles like sea turtles to mammals like bighorn sheep, all across the U.S., using recovery units can mean a better shot at recovery for imperiled species.