This study will perform a coast-wide survey of the extent and status of kelp forests in Oregon.
Why We Care
Kelp are seaweed, known as the ‘trees of the sea’, that grow in large dense groups forming underwater forests with ecological, economic, and cultural value. Kelp is a foundation species that provides habitat and food to myriad marine species, sometimes miles away. Local economies rely on kelp forests to provide food for red sea urchins and habitat for rockfishes and other commercially valuable fish species. Local community identities are built around these fisheries, and local tribes value these species as cultural resources.
Marine heat waves and sea star wasting disease have driven recent collapses of kelp forests in Northern California, and southern and central Oregon kelp forests seem to be following suit. Sea stars are natural predators of urchins, which graze on kelp. In the past two years, the Oregon Department of Fish and Wildlife and commercial sea urchin divers reported an unprecedented increase in purple sea urchins in southern Oregon (~350 million on Orford Reef, a 10,000-fold increase). This massive increase can result in ‘urchin barrens’, where kelp has been grazed away. Because bull kelp is an annual plant that dies and grows back yearly, an imminent risk is the loss of biodiversity of the local spore bank. I: if young kelp are eaten by urchins before they can reproduce, this can result in a regional “kelp desert” aka urchin barren, that is very hard to restore if and when sea urchins decline naturally. Kelp forests have subsequently begun to deteriorate from Brookings near the California border to as far north as Cape Lookout on the northern Oregon coast.
What We Are Doing
This project will involve a wide-ranging coastal snapshot of Oregon's kelp forest habitats to inform management, conservation, and restoration activities. These important habitats have not been aerially surveyed since 2011, and many have undergone significant changes in recent years due to warming oceans, loss of predators, and population booms of purple sea urchins. In addition, coast-wide subtidal surveys of Oregon's kelp forests have never been completed. The recent widespread loss of kelp forests in Northern California has drawn attention to this problem in Oregon and this project intends to address this need.
Several members and partners of the Oregon Kelp Alliance (ORKA) are currently engaged in essential kelp forest management, conservation, and restoration efforts that will be informed by these data. ORKA will use a multifaceted approach to gather data, including aerial surveys using drones, underwater SCUBA surveys of kelp forests, and remotely operated vehicle video surveys to provide a complete and current assessment of kelp forest health in Oregon. These data will provide key information on the health of this important coastal resource, and enable managers and communities to aid in its recovery.
Ben Scheelk of The Ocean Foundation leads as the fiscal sponsor for this project. Co-investigators are Tom Calvanese (Oregon State University), Dr. Sara Hamilton (University of California- Davis), Dr. Sarah Gravem (Oregon State University), Dr. Aaron Galloway (University of Oregon).