'It just sort of breaks your heart'

Nov. 28—Scientists along the West Coast are calling for immediate action to aid the recovery of sunflower sea stars, which have seen catastrophic population declines over the past decade.

Experts say a sea star wasting disease epidemic that began in 2013 has decimated about 95% of the population from the Aleutian Islands of Alaska to Baja California, Mexico.

The decline triggered the International Union for Conservation of Nature to classify the species as critically endangered in December 2020. A petition to list the species under the federal Endangered Species Act was filed in August 2021, and a recommendation from National Marine Fisheries Service is expected in the coming weeks.

Steven Rumrill, the shellfish program leader at the Oregon Department of Fish and Wildlife, said that in his more than 40 years as a marine scientist, he has not seen a widespread decline of a species on the same scale as the sunflower sea star.

The species is important, he explained, as the predator has a disproportionately large effect on the natural environment. He said its disappearance has had cascading impacts, and is perhaps the driving factor in the decline of kelp beds.

Rumrill is one of the leading experts on the West Coast that contributed to a recently published document, "Roadmap to Recovery for the Sunflower Sea Star," which aims to guide scientists and conservationists.

"It just sort of breaks your heart to see a species decline so rapidly to the point of extinction," Rumrill told The Astorian. "At the global scale, we're recognizing that the impacts of humans have had major impacts on populations and lots of extinctions worldwide. Here's one that's happening right in front of our eyes, right on our front doorstep, but just underneath the water."

The roadmap details near- and medium-term steps to prevent further declines and foster recovery of populations. It was completed in collaboration with The Nature Conservancy, National Marine Fisheries Service, California Department of Fish and Wildlife, Oregon Department of Fish and Wildlife, Washington Department of Fish and Wildlife and Alaska Department of Fish and Game.

"We're collaborating across borders," Rumrill said. "And we're working to plan ahead and try to identify the pathway that's needed to help the species recover."

The document noted that while sunflower sea stars were once common and abundant, there is little known about the species' life, history and ecology, including their role in maintaining healthy kelp forest ecosystems.

The sea stars, which are among the largest in the world and can span more than 3 feet, are predators to the kelp-eating sea urchin. Without the predator, sea urchin populations have increased, causing a troubling decline in kelp forests along the West Coast, especially in northern California.

The sea star wasting disease is estimated to have killed over 5.75 billion sunflower sea stars, according to the document, causing a 94.3% decline in the global population.

In the southern part of the range, between Cape Flattery, Washington, and Baja California, declines have reached 99% to 100%. Declines have been slower from Washington state to Alaska, where there has been a more than 87.8% loss.

The cause of the outbreak has not been conclusively identified, but the document points to evidence that warming ocean waters from human-caused climate change increases the severity of the disease. It could even be responsible for triggering the outbreak, according to the document.

Climate change may hinder recovery efforts, the document notes, especially in the warmer, southern end of the range.

Rumrill said listing through the Endangered Species Act could result in federal funding to continue research.

Matthew Burks, a spokesman for the National Marine Fisheries Service, said the decision will be public once it is posted to the Federal Register, which is expected to happen by the end of the year or early next year.

While sunflower sea stars appear to be the most affected by the sea star wasting disease, they are among about 20 documented species of sea stars at risk along the West Coast. And there could be more.

"We just don't have the data at this point to be able to clearly document the way we have been able to do with the (sunflower sea star)," Rumrill said. "So there could be other species suffering the same fate."