Saving Kelp Forests: Abalone Restoration



For over ten years, marine biologist Nancy Caruso has been restoring the kelp forests of Orange County with the help of 5000 k-12 students and 250 volunteer divers. This is the story of her latest effort to boost the area’s depleted abalone population.



Seven species of abalone once teemed along the shores of California. For centuries, native peoples relied on this protein source to sustain them, as evidenced in ancient middens found along the coast, where piles of empty shells can be found. They were also found in middens as far East as the Mississppi River, indicating that they were traded as beautiful shells used for ceremonial vessels and jewelry.

In the early 1900s biologists were quoted in a session of Congress asking for the protection of the abalone because the massive harvest going on at that time “was surely to deplete the natural stocks”. The state of California did not heed this warning until 70 years later when they closed the abalone fishery. By then, it was too late. Two of the seven species were Endangered, and two were listed as Federal Species of Concern.



Nancy Caruso measures an abalone found in the kelp beds.

Three years ago, Get Inspired, an organization I founded to promote the arts and sciences, applied for a permit to restock green abalone (Haliotis fulgens), a Species of Concern, as part of The Orange County Ocean Restoration Project. Now, for the first time in 20 years, the California Department of Fish and Game has issued a permit to enhance the wild stocks.

Our project will use adult abalone, classified as larger than 15 cm (5.9 in). Existing wild abalone populations have been identified and recorded, and the permit allows us to release our outplants (individuals that we raise in a nursery and release to the wild) where there are no wild abalone.



Abalone are raised in captivity in preparation for release into the wild.

Adult abalone have two predators: humans and sea otters. That shouldn’t be a problem because it is illegal to harvest abalone and we will place them on an undisclosed reef, and there are no otters in Southern California. We will track them with multiple methods to monitor their survival. This has never been done before – the problem with past efforts is that they used young abalone, which couldn’t be tracked.

The best part is that this will all be carried out by everyday citizens who are concerned with the health of their oceans. I will train volunteers to identify abalone species and to help me design the tracking and monitoring devices and techniques. The best idea yet came from a 12-year-old who recommended that we tag the abalone with metal and use a metal detector to find them. Brilliant!



Students' engagement in the raising of abalone teaches them about the importance of caring for coastal habitats.

Our goal is to outplant 200 adults and to successfully track and monitor their survival for one year. No one has been able to do that yet. Classrooms in local k-12 schools are raising abalone and volunteer divers will do the outplanting. Abalone farms will supplement the ones we grow in order to reach 200 total over the next two years, releasing half this year and the rest next year. Ultimately, we hope to reach a minimum viable population density of 2000 individuals per hectare. This may take a few years.



Students participate in the raising of abalone by caring for them and measuring their growth.

We are also conducting a similar project with white sea bass. So far, we have raised 300 green abalone and 120 white sea bass in schools in Orange and LA counties. We have trained divers and we are still restoring kelp forests in Orange County through kelp replanting.

If a bunch of scientists were doing this work alone, it would be invisible to the world. Instead, students who worked on this project years ago still ask, “How’s OUR kelp doing?” This is the sign of success. They took ownership of the kelp. It IS theirs. With the involvement of the community, citizens take responsibility of the outcome of the project, and they will make decisions in the future to protect what they worked hard to restore.

Photos courtesy of Nancy Caruso.