The Endangered Species Act has been very successful in preventing species extinctions. Less than 1 percent of the species listed under the act have been lost. 

Steller sea lion – The Eastern distinct population segment of Steller sea lions, listed as threatened under the ESA almost a quarter century ago, has recovered and was removed from the list. The delisting of this population of Steller sea lions—which was once depleted due to harvests, predator control programs, and indiscriminate killing—demonstrates that species can recover with targeted conservation efforts.

Humpback whale – In 2016, NOAA Fisheries revised the listing for humpback whales under the ESA, dividing the whales into 14 distinct population segments and finding that 9 of these distinct population segments do not warrant listing under the ESA. International conservation efforts to protect and conserve whales over the past 40 years proved successful for most populations.

Green sea turtle – In 2016, NOAA Fisheries and the U.S. Fish and Wildlife Service revised the listing for green sea turtles under the ESA, dividing the species into 11 distinct population segments and reclassifying two endangered breeding populations (in Florida and the Pacific Coast of Mexico) as threatened distinct population segments due to successful conservation efforts in the United States and abroad.

Gray whales – Originally listed as endangered under the ESA, the eastern North Pacific population of gray whales was declared to no longer be in danger of extinction and was delisted in 1994. Overall, the population continues to increase and is currently estimated to include over 26,000 whales. All gray whales are protected under the MMPA, and the western North Pacific population of gray whales remains listed as endangered under the ESA.