Scientists Are Growing Kelp in the Lab To Save California’s Kelp Forests From Urchin Invasion

California's kelp forests, which provide habitat for hundreds of marine species and help fight climate change, have been decimated by a series of environmental shocks in the past decade.

However, a new wave of innovative research and restoration efforts is showing promise in bringing back these vital ecosystems.

The problem: a perfect storm of kelp killers

(Photo : JOSEPH PREZIOSO/AFP via Getty Images)

Kelp forests are underwater forests of large brown algae that grow along the coastlines of many temperate regions.

They are among the most productive and diverse habitats on Earth, supporting fisheries, tourism, and coastal communities.

They also play a key role in mitigating climate change by absorbing carbon dioxide from the atmosphere and storing it in their biomass.

However, California's kelp forests have been hit hard by a combination of factors that have reduced them to a fraction of their former extent.

According to satellite imagery, the state's northern coast has lost around 95% of its kelp forest since 2014, while the central coast has also experienced significant declines.

The main culprits behind this kelp loss are:

A marine heat wave that started in 2013 and lasted for several years, creating warm and nutrient-poor conditions that stressed the kelp and reduced its growth and survival.
A disease outbreak that wiped out the sunflower sea stars, a major predator of purple sea urchins, which are voracious grazers of kelp.
An explosion of purple sea urchin populations, which have grazed the kelp forests down to bare rock and created "urchin barrens" that prevent kelp recovery.

These changes have had devastating impacts on the marine life and human communities that depend on the kelp forests for food, income, and recreation.

Many species, such as abalone, rockfish, and sea otters, have lost their habitat and food source, while fishermen, divers, and tourists have seen their livelihoods and enjoyment diminished.

The solution: a collaborative and adaptive approach to kelp restoration

Restoring the kelp forest

In response to this crisis, a coalition of researchers, non-profits, government agencies, and local stakeholders has been working together to protect and restore the kelp forests using a variety of methods and strategies. Some of the key initiatives include:

Urchin removal

This involves manually removing or crushing the excess urchins from selected sites to reduce their density and grazing pressure and allow kelp to regrow.

This has been done by commercial urchin divers, who have been supported by state funding and incentives, as well as by volunteers and scientists, who have been conducting monitoring and evaluation of the results.

So far, this method has shown promising results, with significant increases in kelp density and diversity at some of the restoration sites.

Lab-grown kelp

This involves cultivating kelp spores in a laboratory and then transplanting them onto artificial substrates or existing kelp holdfasts (the structures that anchor the kelp to the seafloor) at the restoration sites.

This aims to enhance the natural recruitment and survival of kelp by providing a source of healthy and genetically diverse individuals that can withstand environmental stressors.

This method is still in the experimental stage, but has shown potential for increasing kelp cover and biomass at some of the restoration sites.

Community engagement

This involves raising awareness and involvement of the public and the stakeholders in the kelp restoration efforts, as well as incorporating their knowledge, values, and preferences into the decision-making process.

This aims to foster a sense of stewardship and ownership of the kelp forests, as well as to ensure that the restoration goals and outcomes are aligned with the social and economic needs and aspirations of the coastal communities.

This method is essential for building trust and collaboration among the diverse actors involved in the kelp restoration, as well as for ensuring the long-term sustainability and resilience of the kelp forests38.

These methods are not mutually exclusive, but rather complementary and synergistic, as they address different aspects and scales of the kelp restoration challenge.

Moreover, they are adaptive and flexible, as they allow for learning and adjustment based on the feedback and outcomes of the restoration actions.

This is crucial, as the kelp forests are dynamic and complex systems that are influenced by multiple and changing environmental and human factors.

Also Read: Kelp Forest Replanting by 2040 Shows Crucial to Save from Decline, Brink of Extinction

The future: a vision for a thriving kelp social-ecological system

The kelp restoration efforts in California are not only aimed at restoring the kelp forests to their previous state, but also at transforming them into a more resilient and diverse system that can cope with future climate change and other disturbances.

This requires a holistic and integrated approach that considers the ecological, social, and economic dimensions of the kelp social-ecological system, and that balances the trade-offs and synergies among different objectives and interests.

To achieve this vision, the California Department of Fish and Wildlife, in partnership with the California Ocean Protection Council, is developing a statewide, ecosystem-based, adaptive Kelp Restoration and Management Plan (KRMP) for giant kelp and bull kelp.

The KRMP will provide a framework and guidance for kelp restoration and management across the state, based on the best available science and stakeholder input.

The plan will also identify the research and monitoring needs, the funding and policy opportunities, and the communication and outreach strategies to support the implementation and evaluation of the kelp restoration and management actions.

California is leading the way in kelp restoration, not only by applying innovative and effective methods, but also by fostering a collaborative and adaptive culture among the kelp restoration practitioners and participants.

By doing so, the state is not only saving its kelp forests, but also enhancing its ocean health and resilience, and supporting its thriving coastal communities.

Tags kelp, lab, scientists, california, urchin