Center for Biological Diversity

For Immediate Release, May 16, 2018

Contact: 

Abel Valdivia, (919) 932-0199, avaldivia@biologicaldiversity.org

Study: Marine Mammals, Sea Turtles Protected by Endangered Species Act Are Recovering

78 Percent of Studied Populations Grew, Just Two Species Declined After Listing

OAKLAND, Calif.— Most marine mammals and sea turtles in the United States that are protected by the Endangered Species Act are recovering, according to a new study by scientists at the Center for Biological Diversity.

The best available population data for 23 marine mammals and nine sea turtles shows that 78 percent of them — including most large whales, Florida manatees, California sea otters, and green sea turtles — experienced substantial population increases after being protected by this landmark federal law.

“The Endangered Species Act works. This is great news at a time when our oceans face growing threats from climate change, overfishing and pollution,” said Dr. Abel Valdivia, the Center’s ocean scientist and lead author of the study. “It’s easy to get discouraged as we watch human activities destroy marine ecosystems. But our study shows we can still save whales and other endangered species if we just make the effort.”   

The study, which is under review at the scientific journal PLOS ONE and appears as a preprint in the BioRXiv server today, looked at all marine mammal and sea turtle species protected by the Act. The good news is being released just before Endangered Species Day on May 18.

The study analyzed only those species with reliable and high-quality data, making the findings of this comprehensive survey of the scientific literature a powerful indicator of endangered species’ recovery.

According to the study, most species are on the path to recovery. Three species of marine mammals and two species of sea turtles remained unchanged after listing, which may indicate population stability. Just two marine mammal species, the Hawaiian monk seal and Southern Resident killer whale, continued to decline after being listed. No listed sea turtle populations declined.

Conservation measures triggered by the Act include habitat protections, science-based management measures to safeguard the species, and recovery planning. The Endangered Species Act has required devices that allow sea turtles to escape from fishing nets, protected whales from deafening sonar, reduced disorienting lighting from sea turtle nesting beaches, among other protections.  

The study found that species listed for more than 20 years were more likely to be recovering than recently listed species, another sign the Act is effective if federal officials follow its mandates.

“People can see more humpback whales migrating along the West Coast, which is a success story everyone can appreciate,” Valdivia said. “Yet Southern Resident killer whales still struggle against extinction, partly because the federal government missed its own deadline to expand critical habitat protections. The Act works well when officials effectively use the tools it provides.”

The study, titled “Marine mammals and sea turtles listed under the Endangered Species Act are recovering,” was primarily authored by Dr. Valdivia. Marine mammals and sea turtles make up 36 percent of the 161 marine species listed under the Act.

See a fact sheet of the study.

Green sea turtle

Humpback whale

California sea otter

Green sea turtle population

Humpback whale population

California sea otter population

Green sea turtle photo by Mark Sullivan, NOAA permit 1013707. Humpback whale photo courtesy NOAA. California sea otter photo by Mike Baird. Graphs by Abel Valdivia, Center for Biological Diversity. Images are available for media use.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.6 million members and online activists dedicated to the protection of endangered species and wild places.

www.biologicaldiversity.org

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