Frequently Asked Questions

Find answers to frequent questions about restoring kelp on the Sonoma Coast.

NOAA’s Greater Farallones and Cordell Bank National Marine Sanctuaries and Office of Habitat Conservation are partnering with Greater Farallones Association and the California Department of Fish and Wildlife to restore bull kelp forests on the Sonoma Coast in Greater Farallones National Marine Sanctuary. Other key restoration partners include academic researchers with California State University/Sonoma State University, San Francisco State University/Moss Landing Marine Labs, University of California Davis/ Bodega Marine Lab, University of San Diego/Scripps Institute of Oceanography; Stanford University, and Tribes, including the Kashia Band of Pomo Indians of the Stewarts Point Rancheria.

Q: Why does the Sonoma Coast need kelp intervention and restoration?

A: Kelp forests along the coastline of Sonoma and Mendocino counties have deteriorated dramatically in just a few short years. Greater Farallones National Marine Sanctuary has experienced a series of compounding stressors that have led to extensive kelp declines in recent years, starting in 2014, and loss of critical ecosystem function. Kelp habitat declines have reached 95% in some areas.

The loss of kelp has led to ecological changes that have left many species such as fish, invertebrates, seals, sea lions, and abalone without a habitat and shelter, and resulted in the closure of important fisheries. Without intervention, bull kelp is at risk of losing its genetic diversity with persistent losses.

Q: What led to the significant loss of kelp along the Sonoma and Mendocino coast?

A: The sea star wasting syndrome led to the decline of 20 species of sea stars, including the sunflower sea star, a primary predator of urchins that was once common along the Pacific Coast of North America. In addition, southern sea otters, which eat purple urchins, were extirpated during the fur trade along the Sonoma and Mendocino coast in the early 1800’s. Without predators, the purple urchin population exponentially increased to 60% above previously recorded numbers. The purple urchins consumed the kelp, which led to urchin barrens (areas with very little to no kelp and with many purple sea urchins).

Q: How do marine heat waves affect kelp?

A: When the waters along the coast experience higher ocean temperatures, the upwelling of cold, nutrient-rich water is suppressed. Kelp need this cold, nutrient-rich water to survive, and during a heatwave, there is a noticeable reduction in primary productivity that leads to large-scale mortality of kelp forest communities. Kelp forests are naturally resilient to El Niño fluctuations, and can typically recover quickly, however kelp forests cannot recover as efficiently to these natural fluctuations when other human-caused stressors, such as marine heatwaves, are present or persist for long periods of time. This decline in kelp resilience is evident following events such as the recent multi-year marine heatwave.

Q: Is the sunflower star repopulating the North Coast?

A: The sunflower sea star (Pycnopodia helianthoides) was listed as critically endangered by the International Union for the Conservation of Nature (IUCN) in 2020. NOAA Fisheries proposed listing the sunflower star as threatened under the Endangered Species Act in March, 2023. Sunflower star cultivation in lab settings is being researched by several project coordinators to consider reintroduction.

Q: Will there be an economic impact as a result of the kelp restoration project?

A: Healthy ecosystems support businesses and the economy throughout Sonoma Coast communities.The loss of kelp forests has led to total collapse of the commercial red urchin fishery, a $3 million annual value of commercial landings, and to the closure of the recreational red abalone fishery, a $44 million annual non-market value. The primary kelp restoration approach is removing the high numbers of purple urchins from former kelp forests and keeping them at bay while baby kelp is outplanted. Greater Farallones Association purchases purple urchins collected from the sites by out-of-work commercial urchin divers. Healthy kelp habitat supports fisheries, such as the commercial urchin fishery.

Q: How were the restoration sites selected for kelp restoration?

A: Restoration sites were prioritized for the potential for long-term success, with a focus on where kelp has shown more resilience to urchins. The variables considered include:

• The historic range of kelp along the coast
• The condition of the seafloor where kelp lives
• Geographic location of historically isolated kelp beds
• Understanding of how sediment moves on the seafloor
• Cultural significance
• Human caused stressorsState-designated marine protected area status
• Areas of value to the red abalone recreational fishery and red urchin fishery
• Protection from wave energy
• Exposure and proximity to boat launch sites to access restoration sites

Q: Why would we conduct restoration efforts that could be later wiped out by ongoing warming temperatures in the ocean?

A: The National Marine Sanctuaries Act mandates that national marine sanctuaries develop and test methods to enhance degraded habitats or restore damaged, injured, or lost sanctuary resources. One of the main goals for kelp restoration is to increase resilience to region-wide stressors. Projects in Southern California and in other areas have demonstrated that restored kelp forests recover more quickly following warm water events. A marine heatwave could (and likely will) suppress kelp growth on a large scale again—or spur another purple urchin population explosion. Our goal is to preserve the genetic diversity in local populations to facilitate faster recovery, by restoring strategic locations for spore dispersal and to prevent the loss of kelp-dependent fish and invertebrate species. This habitat is significant enough that we have to intervene to provide space, time, and resources for the ecosystem to be as resilient as possible in the face of a changing ocean and planet. This region experiences fluctuations in ocean conditions regularly. With some support from science and intervention, kelp forests can return. If we do nothing, we face potential extinction of local spore banks of bull kelp, reducing the potential for kelp to return on its own and leaving the ecosystem in a degraded state.

Q: How will this effort be funded?

A: NOAA’s Greater Farallones National Marine Sanctuary has invested resources towards characterizing and quantifying the loss of kelp and bringing experts and stakeholders together to identify solutions. NOAA will focus available funding to support this effort and work with partners to secure additional public and private funds. As of July 2024, nonprofit partner Greater Farallones Association has secured more than $9.5 million to initiate restoration efforts including $4.9 million from NOAA’s Office of Habitat Conservation, $2 million from congressional appropriations (administered by NOAA), $1.5 million from the National Fish and Wildlife Foundation, $228,000 from the Pacific States Marine Fisheries Commission, $172,000 from the California Department of Fish and Wildlife, and over $200,000 from the University of California Santa Cruz. This effort is carried out with strong collaboration between GFA, GFNMS, NOAA Office of Habitat Conservation and academia, Tribes, and state government agencies.

Q: Will there be any regulatory changes that affect access to or types of activities allowed at the kelp restoration sites? Will there be any restrictions on diving, fishing, or boating at the restoration sites?

A: Access to the water at the restoration sites will not be restricted. Anyone using the same locations where restoration activities are being carried out will need to be aware that there are divers underwater and typical dive flag alerts will be used when carrying out diving. Local land-based authorities will be informed and new signage developed in partnership with Fort Ross Conservancy will alert ocean users to be aware of activities happening on and under the water.