Proposed Bull Kelp Harvest Limits Could Help Address Climate-Driven Collapse of Vital Marine Algae

California seeks to sustain marine ecosystem—and coastal communities—as it works on longer-term plan

Navigate to:

Proposed Bull Kelp Harvest Limits Could Help Address Climate-Driven Collapse of Vital Marine Algae
california, kelp
Some of California’s most intact bull kelp forests—which provide food and shelter for hundreds of species of ocean wildlife, including whales, salmon, rockfish, and abalone—are found near Monterey. This important marine algae often resembles a bull whip after it washes up on beaches and dries, which is why it’s called bull kelp. In Northern California, it is harvested as a food item.
Laura Tesler

Editor's note: This article was updated on Sept. 1, 2021, to include additional information about the changes in kelp regulations that the California Fish and Game Commission is considering.

The past seven years have been devastating for Northern California’s bull kelp forests, which are crucial for fighting climate change, sheltering sea life, and supporting coastal economies. Warming ocean waters and an explosion of purple sea urchins—voracious bull kelp predators—have all but wiped out this important marine algae along large swaths of the North Coast.

In response to the crisis, the California Department of Fish and Wildlife (CDFW) is recommending that the state temporarily close bull kelp harvest in waters off Sonoma and Mendocino counties, cap harvest in Humboldt and Del Norte counties, and suspend review of any new lease applications for three kelp beds that have never been used for larger-scale harvest. This would help give CDFW time to craft a statewide kelp management plan.

In July, CDFW presented these proposed precautionary measures to the California Fish and Game Commission (CFGC) Marine Resources Committee, which in turn recommended forwarding the draft regulations to the full CFGC. At its August meeting, the CFGC voted to schedule formal consideration of the proposal later this year. This step will include reviewing a range of harvest limits for Sonoma and Mendocino counties, from a complete prohibition to a maximum of 2,000 pounds per year. If the proposal is approved, final adoption of the new rules could take place in early 2022.

The cascading effects of climate change, rather than the small-scale artisanal harvest practiced on the North Coast, drove the recent bull kelp collapse. But given the unprecedented duration of the collapse, uncertainty about kelp regrowth, and the continued effect of warming waters on kelp forest health, CDFW’s precautionary approach to limiting bull kelp harvest can allow scientists to gain a better understanding of what’s needed for sustained long-term recovery.

It is essential that the state get this right, given kelp’s vital role in California’s marine ecosystem. Kelp provides food and habitat for salmon, rockfish, and hundreds of other species. And along with other marine vegetation, kelp absorbs an estimated 20 times more carbon dioxide per acre than forests on land. In fact, studies suggest that worldwide, kelp may sequester more carbon than all other marine plants combined. This potential to fight climate change has never been more important, as evidenced by rising seas, historic droughts, devastating wildfires, heat waves, and other increasingly frequent consequences of a warming planet.

After seven years of bull kelp declines, coastal communities that depend on healthy kelp forests for jobs and recreation are rooting for recovery. The proposed harvest hiatus can contribute to experts’ knowledge of how to achieve that recovery while CDFW crafts a thoughtful, comprehensive plan that gives the state the tools it needs to manage kelp with the larger ecosystem in mind.

Jos Hill is a project director and Gilly Lyons is an officer with The Pew Charitable Trusts’  conserving marine life in the United States project.

Spotlight on Mental Health

Composite image of modern city network communication concept

Learn the Basics of Broadband from Our Limited Series

Sign up for our four-week email course on Broadband Basics

Quick View

How does broadband internet reach our homes, phones, and tablets? What kind of infrastructure connects us all together? What are the major barriers to broadband access for American communities?

Pills illustration
Pills illustration

What Is Antibiotic Resistance—and How Can We Fight It?

Sign up for our four-week email series The Race Against Resistance.

Quick View

Antibiotic-resistant bacteria, also known as “superbugs,” are a major threat to modern medicine. But how does resistance work, and what can we do to slow the spread? Read personal stories, expert accounts, and more for the answers to those questions in our four-week email series: Slowing Superbugs.

Explore Pew’s new and improved
Fiscal 50 interactive

Your state's stats are more accessible than ever with our new and improved Fiscal 50 interactive:

  • Maps, trends, and customizable charts
  • 50-state rankings
  • Analysis of what it all means
  • Shareable graphics and downloadable data
  • Proven fiscal policy strategies


Welcome to the new Fiscal 50

Key changes include:

  • State pages that help you keep track of trends in your home state and provide national and regional context.
  • Interactive indicator pages with highly customizable and shareable data visualizations.
  • A Budget Threads feature that offers Pew’s read on the latest state fiscal news.

Learn more about the new and improved Fiscal 50.