25447 Industrial Blvd. Hayward, CA 94545

Interview with Kristin Aquilino, Research Biologist with Bodega Marine Lab, Explains a New Hope for the Endangered White Abalone

Adult white abalone
An endangered adult white abalone looks out from under its shell. The animal is part of a captive breeding program led by UC Davis Bodega Marine Laboratory.
Image courtesy of Kristin Aquilino/UC Davis.

Once revered for their sweet and delicate taste amongst seafood connoisseurs, the white abalone was decimated by a poorly managed fishery. Now considered nearly extinct in the wild, biologists have used living lab specimens to spawn and create baby abalone for the first time in almost a decade. The hope is that eventually we will be able to replenish the wild population of this beautiful giant snail.

The Office of Protected Resources, housed under NOAA’s National Marine Fisheries Service, provides funding for researchers at UC Davis’ Bodega Marine Lab to continue their white abalone captive breeding and enhancement program. We had a conversation with Kristin Aquilino, a research biologist with Bodega Marine Lab, to gain a better insight on her amazing work with white abalone.

Do you believe that we can restore the wild population of white abalone?  Why is it important that we do so?

I believe we have an obligation to restore white abalone. We are responsible for their current condition – we simply harvested so many of them from the ocean that there are too few left to reproduce successfully. Abalone are ‘broadcast spawners’ so they release their eggs and sperm into the water column, and that’s where fertilization happens. When male and female abalone are more than a couple of meters apart, successful fertilization is almost impossible. Unfortunately, most of the white abalone left in the wild are nowhere near another white abalone, so they’re effectively sterile.

On the plus side, I believe we have all the tools needed to restore white abalone. It will take a long time before wild populations are self-sustaining, but I think it is a very achievable goal.

How are white abalone ecologically valuable?

We know much less about white abalone ecology than the ecology of other abalone species. We harvested most of them before we had a chance to study them in the wild. The animals that remain are in such deep water that we need a remotely operated vehicle just to access them, and the few that are left are also so sparse they are very difficult to find.

Abalone move energy up the food web: Abalone eat kelp and other seaweed, and then predators, such as seastars, octopuses, crabs, or fish, eat abalone. Grazers like abalone can be very important in marine environments where there is limited space for animals to attach to the rock. By clearing away some of the seaweed, grazers can open up space for other organisms to settle, creating a more diverse habitat.

White abalone research
Kristin examines juvenile white abalone under a microscope.
Image courtesy of Karin Higgins/UC Davis.

What is a typical day like for you?

I don’t really have a ‘typical’ day. A lot of what I do from day to day depends on the season. Right now, I spend much of my time making preparations for the upcoming spring spawning season.

Animal care and facilities maintenance are top priorities throughout the year because having a successful breeding program requires that animals are healthy. We have two fantastic technicians that help with this. We check our facilities twice a day to make sure the pumps, filters, aeration, temperature controls, lighting systems, and UV treatment are working properly. We also make sure that the animals have plenty of food, and that their tanks are clean. I’m pretty certain we have some of the most pampered abalone in the world here at BML.

Has your work been successful?

We’ve had great success so far, and I’m very excited about the potential for even greater success in the future. Between 2003 and early 2012, there was no successful captive reproduction of white abalone. Since BML first received a permit to breed white abalone in 2011, we have successfully reared offspring from three spawning attempts, more than tripling the number of white abalone we have in captivity.

We have also improved the condition of our captive animals. For example, we constructed a new facility for our broodstock that has higher flows, temperature control, and lighting that mimics the natural photoperiod in the white abalone’s native range in southern California. The broodstock have grown four times faster since moving into this new system six months ago than they did in the previous two years.

Our recent success can get us to make even greater strides toward wild white abalone restoration. To get to the point where we can start testing outplanting techniques, we really need to ramp up captive production. Now that we have more animals in the program, we can start experimentally testing ways to optimize growth and reproduction. It’s a very exciting time for white abalone.

What do you think were the successful elements of inducing captive abalone to spawn?

Our recent spawning can partially be contributed to our collaborative efforts. By coordinating spawning attempts among multiple white abalone holding facilities, we increased the number of animals in a spawning attempt, which increased the likelihood of having both male and female abalone spawn. I also attribute a portion of our recent success simply to chance, and taking chance out of the equation is the goal of our research. We need to figure out how to reliably increase production of white abalone in captivity, and most importantly, we need to figure out what conditions trigger them to become reproductive.

White abalone seem to only ripen their gonads once a year during the late winter or early spring, and right now, they aren’t becoming very ripe in captivity. When we spawn white abalone, they are giving us all the eggs and sperm that they have, but it’s often not very many, or the ones they release are immature. If we can figure out what conditions promote gonad maturation in the months leading up to spawning season, we can hopefully drastically increase production.

How has your work benefited from abalone aquaculture?  What can the aquaculture industry learn from your work?

The abalone aquaculture industry does a great job of producing large numbers of high-quality offspring, and we employ the best industry techniques and then adapt them for white abalone. Working with a naturally abundant species like red abalone has its advantages over working with an endangered species, one of which is an ability to collect ripe broodstock from the wild throughout much of the year. In contrast, we have to work with the few captive animals we have – no new wild white abalone collection is allowed under the ESA permit – which means we have to entice the same animals to become reproductive every year away from their natural environment.

If we can figure out the precise conditions that get abalone to become reproductive in captivity, particularly outside of their regular spawning season, it might be useful to farms because they could potentially have greater control over when they create new cohorts and use the same high-quality broodstock repeatedly.

Are white abalone more difficult to farm than other abalone?  Why?

White abalone have the disadvantage of being very rare – so we only have a very small population of captive animals to work with. Because we can’t introduce any new genetic material into the captive population by collecting new broodstock from the wild, we need to be wary of potential inbreeding depression. With the narrower breeding season for white abalone, we also have fewer opportunities to spawn them throughout the year.

White abalone tend to have thinner shells and their foot is more susceptible to being cut, so we have to be a little more cautious handling them than other species. Abalone are hemophiliacs, so their blood doesn’t clot, which means even a small cut could cause mortality. I have heard that white abalone meat is the most tender of all California abalone species, which is part of the reason it was targeted in the fishery, and I wonder if their relative fragility and tastiness are related.


What is your favorite element about working to save an endangered species?

I really enjoy being part of a large, interdisciplinary team of scientists. BML has an amazing amount of expertise relating to abalone health, reproduction, and ecology, and we have outstanding facilities for conducting abalone research. I also really enjoy working to save a species that is such a significant part of our history. Abalone have been very important to the diet and commerce of people living in this area for centuries, and abalone continue to contribute to California’s economy, both through farms throughout the state and recreational diving in northern California. I’m hopeful that our work will allow white abalone to continue to be an important resource in the future.

 Creating a future for an endangered species

Without the work of biologists like Kristin, the white abalone and other endangered species would have no future. Her work is exciting and inspiring – she has the opportunity to save an endangered species while working with an excellent team of scientists. Conservations, biologists, and seafood lovers alike are rooting for their success. Let us hope in the coming years that we can watch these little baby abalone grow and spawn, creating generation after generation and eventually igniting a fantastic rebound of the wild population. We all have an opportunity to do our part. You too can ensure that our oceans provide their bounty for many future generations. Choose your seafood from Pucci Foods, a distributor that is committed to working with partners who practice sustainable fishing and farming methods.


Share the Post:

Related Posts