Science & Environment

Group seeks endangered species protection for West Coast bull kelp

By Bradley W. Parks (OPB)
Sept. 5, 2022 1 p.m.

Bull kelp is critical to Oregon coastal ecosystems that historically supported sea otters, urchins and sunflower sea stars.

The Center for Biological Diversity is seeking Endangered Species Act protections for bull kelp.

The Center for Biological Diversity is seeking Endangered Species Act protections for bull kelp.

Sara Hamilton / Oregon State University

An environmental group is seeking Endangered Species Act protections for underwater forests of bull kelp along the West Coast.


The Center for Biological Diversity on Thursday submitted a petition to the National Oceanic and Atmospheric Administration to grant endangered status to the long stalks of kelp that are critical to Oregon coastal ecosystems.

“Bull kelp face threats from climate change, sea urchin predation and coastal development,” said Mukta Kelkar, science intern with the Center for Biological Diversity who co-authored the petition. “And so we’re asking that the federal government step in and protect them under the Endangered Species Act.”

Related: Meet the delicious purple sea creature destroying Pacific kelp forests


Bull kelp create balance in Pacific Coast communities of sea otters, urchins and sunflower sea stars. The towering brown algae also store carbon and support a vast array of marine life like salmon and abalone.

Urchins eat kelp, but otters and sea stars historically kept the spiky salad-eaters in check.

However, sea otters largely disappeared from the subtidal ecosystem of the U.S. West Coast, as trappers went after their pelts in the 18th and 19th centuries. Warming oceans have also caused rapid spread of sea star wasting disease, which has decimated sunflower sea stars, another urchin predator.

That’s led to a proliferation of purple sea urchins that are mowing down kelp forests, creating underwater wastelands and putting this vital ecosystem at risk.

“Purple sea urchins take over the previous kelp habitat and graze very destructively on what’s left,” Kelkar said. “And after that happens, it’s very difficult for kelp to recover.”

Kelkar added that increased ocean temperatures and frequent marine heatwaves driven by climate change are creating conditions for bull kelp decline.

The Endangered Species Act safeguards a long list of marine species. Kelkar said, if listed, bull kelp would be the first marine plant or algae to earn those protections.

NOAA confirmed the agency has received the petition but did not comment on it. Receipt of the petition kicks off a 90-day review process during which NOAA will determine whether bull kelp may warrant protection under the Endangered Species Act.