The Kelp Forest Ecosystems Off the Southern California Coast Provide Habitat and Food for Over 700 Marine Species
The kelp forest ecosystems off the southern California coast are known to be some of the most diverse and productive ecosystems in the world. They are vital for providing habitat and food for over 700 marine species, including kelp bass, California spiny lobster, abalones, marine mammals, birds, and fish. Many of these kelp forest species are the targets of California’s most lucrative sport and commercial fisheries. SCUBA divers travel from around the world to experience the beauty beneath the waves.
Kelp forests also protect neighboring coastlines from erosion and pull in carbon dioxide from the ocean as they grow. Thus, kelp forests are a great way to address climate change while enriching our ocean with life. The Bay Foundation (TBF) is a world leader in the effort to restore kelp forests, supporting international partnerships, method development and technological innovation.
Project Highlights
Progress to Date
With its many partners, TBF leads and operates one of the largest and most successful kelp projects in existence. Off the Palos Verdes Peninsula, a team of fishermen, academic researchers, and numerous agencies have directly supported The Kelp Restoration Project.
- 58 acres of restored kelp forests off the Palos Verdes Peninsula
- 5 commercial urchin fishermen employed throughout project
- Over 10,000 hours underwater restoring kelp
- Purple urchin reduced from an average of 30/m2 to ~2/m2
- Red urchins increase in gonad (uni) weight by 168% in restoration sites off the PV Peninsula
- Increases in kelp, invertebrate, and overall fish diversity and biomass observed
- Recreationally targeted finfish increases in density and biomass
Factors Leading to the Loss of Giant Kelp Canopy Cover
Over the past 100 years, the Palos Verdes Peninsula has lost approximately 80% of its giant kelp canopy cover. During this time, sedimentation, development, urban runoff, and storms have limited kelp growth. Concurrently, overfishing in kelp forests has contributed to the loss of key sea urchin predators and competitors. As a result, purple sea urchins have become too numerous on the reef, overgrazing the kelp and preventing it from returning in the future.
Restoring This Vital Ecosystem
The Kelp Forest Restoration Project converts these desolate monoculture sea urchin barrens back into diverse and resilient ecosystems by reducing the density of sea urchins on the reef. Without intervention and direct restoration, kelp forests may take decades to return. To speed up the recovery process of this vital ecosystem, TBF has initiated, and currently leads, a partnership of researchers, fishermen, and conservationists in the removal of the overly abundant purple sea urchins, allowing for the natural return of the kelp forest and the wildlife it supports.
Improving the Health of Sea Urchins
Sea urchins that live in the barrens have access to little or no food due to the lack of kelp on the reef. Consequently, urchins found in barrens are generally small and malnourished. Conversely, sea urchins living in kelp forests are healthier and larger. They also have larger gonads, or ‘uni’, the edible part of the sea urchin, prized on sushi menus.
Progress to Date
With its many partners, TBF leads and operates one of the largest and most successful kelp projects in existence. Off the Palos Verdes Peninsula, a team of fishermen, academic researchers, and numerous agencies have directly supported The Kelp Restoration Project.
- 58 acres of restored kelp forests off the Palos Verdes Peninsula
- 5 commercial urchin fishermen employed throughout project
- Over 10,000 hours underwater restoring kelp
- Purple urchin reduced from an average of 30/m2 to ~2/m2
- Red urchins increase in gonad (uni) weight by 168% in restoration sites off the PV Peninsula
- Increases in kelp, invertebrate, and overall fish diversity and biomass observed
- Recreationally targeted finfish increases in density and biomass
Factors Leading to the Loss of Giant Kelp Canopy Cover
Over the past 100 years, the Palos Verdes Peninsula has lost approximately 80% of its giant kelp canopy cover. During this time, sedimentation, development, urban runoff, and storms have limited kelp growth. Concurrently, overfishing in kelp forests has contributed to the loss of key sea urchin predators and competitors. As a result, purple sea urchins have become too numerous on the reef, overgrazing the kelp and preventing it from returning in the future.
