How Climate Change Uncertainty Helped Get Sea Lions Off The Endangered Species List

CREDIT: AP Photo/Lionel Cironneau

Steller sea lion, Boris, 15-years-old, eats a fish.

Uncertainty surrounding the effects of climate change just helped the world’s largest sea lion become the first animal to be taken off the U.S. endangered species list in nearly two decades.

In a final rule posted to the Federal Register on Tuesday, The National Oceanic and Atmospheric Administration said populations of the eastern Steller sea lion — a pudgy pinniped dwarfed only by the walrus and two species of elephant seals — have increased enough to warrant its removal from the list, despite multiple assertions that the animals’ habitat will steadily degrade as a result of climate change.

From the rule:

While [NOAA] is concerned about multi-faceted adverse impacts of climate change and ocean acidification over the next 50-100 years on marine ecosystems of which this [distinct population segment] is a part, based on the best scientific and commercial data available, we cannot accurately predict the impacts of these factors …. Thus, in the absence of substantial information to the contrary, we conclude that global warming and ocean acidification are not likely to cause the eastern DPS of Steller sea lion to become in danger of extinction throughout all or a significant portion of its range within the foreseeable future.

The decision comes despite warnings from the Marine Mammal Commission (an independent government agency) that climate-related habitat degradation is “one of the leading hypotheses to explain the loss of Steller sea lion [breeding colonies] in California,” as the lions are shifting their distribution northward as the climate warms. NOAA had also received comments from the U.S. National Park Service, stating that future climate change impacts are likely to affect the population at the southern end of species’ ranges.

NOAA agreed that climate change — particularly in the southern part of the sea lions’ habitat — was “a concern,” but noted that the animals are not dependent on ice, and therefore not as critical an issue.

The agency also declined to respond to concerns that global warming and increasing acidity in the ocean pose a “potential threat” to the sea lions’ underlying food webs, saying the issue is “complicated by the rapidly evolving understanding of this complex threat, the uncertainty about how Steller sea lions might respond, and the inability to predict a response by the [sea lions] reliably within the foreseeable future.”

“Clearly, the issue is not specific to Steller sea lions or their habitat,” the agency said.

Populations of the sea lions have exceeded the agency’s goal of an annual rate of 3 percent since the species was put on the endangered species list in 1990, averaging a 4.18 percent annual growth rate in the last 20 years, the agency said. The growth is partially credited to increased protections under the federal Marine Mammal Protection Act, which largely prohibits the targeting killing of marine mammals for human activities.

NOAA’s decision to remove the sea lions from the list was particularly noteworthy considering the last animal to be removed was the eastern North Pacific gray whale, taken off the threatened list in 1994, the agency said. The proposal to delist the sea lion saw more than 1,000 comments submitted for and against the delisting.

The decision to remove the eastern breed of the Steller lion does not affect the endangered status of the distinctly different western population with the same name, which includes sea lions throughout Northern Alaska, Asia and the Aleutian Islands.