Marine mammals and turtles rebound after endangered species protections
A new study shows broad recovery but doesn’t dive into the problems that remain.
By Emily Benson/High Country News
In the late 1970s, somewhere between 220,000 and 265,000 Steller sea lions swam, dove and fished in the western part of the Gulf of Alaska and the Bering Sea. But by the turn of the century, fewer than 50,000 remained.
By then, the pinnipeds had been protected under the Endangered Species Act. They were listed as threatened in 1990, and those living in the western gulf and the Bering Sea were later recategorized as endangered. That endangered population of sea lions has started to rebound: Though improvements haven’t been uniform across their range, their numbers grew by about a quarter between 2003 and 2015.
Those Steller sea lions are one of the more than 60 marine mammal and sea turtle populations sheltered by the Endangered Species Act since its inception in 1973. Now, new peer-reviewed research conducted by scientists from the Center for Biological Diversity, a conservation-focused nonprofit, suggests that protection has largely been effective, with a paper title that succinctly sums up their findings: “Marine mammals and sea turtles listed under the U.S. Endangered Species Act are recovering.”
To measure the impact of the Endangered Species Act, the researchers analyzed how population numbers shifted after listings. For 31 protected marine mammals and sea turtles — a subset of species that met certain criteria, including living and reproducing mostly in U.S. waters, and for which enough data were available to measure changes — the scientists determined whether the population grew larger, stayed the same, or shrank. They found that about three-quarters of the marine mammal and sea turtle populations increased after listing. “We just need to put our effort into it in order to protect these species,” said Abel Valdivia, the lead author of the study, who now works for RARE, a conservation group based in Arlington, Virginia. “They do have a really high capacity for rebounding if some conservation measures are put in place.”
>> Read more about what scientists are saying and how some populations are not rebounding.
