California sea lion populations have fully rebounded, according to a new assessment by scientists from the National Oceanic and Atmospheric Administration‘s Alaska Fisheries Science Center and Southwest Fisheries Science Center.
The California sea lion population in the United States has steadily increased since the early 1970s: Before the 1970s, the species’ population suffered from declines due to market hunting, bounties, chemical pollutants, and other factors. California sea lions reached carrying capacity in 2008 before unusually warm climate and ocean conditions caused their numbers to decline once again.
The study found sea lion numbers fluctuated in response to environmental changes, especially as warmer temperatures affect their food supply and prey.
“This is not just a story about continued growth of the population,” said Robert DeLong, leader of the Alaska Fisheries Science Center’s California Current Ecosystems Program and a co-author of the study, in a press release. “These last several years have brought new environmental stresses to the California Current, and we’ve seen that reflected by the seal lions.”
The recovery signifies a significant success for the Marine Mammal Protection Act, a piece of legislation enacted in 1972 aimed at preventing marine animal depletion as a result of human activity.