Aquatic Nursery: A new role for red abalone
Red abalone have important positions in the Aquatic Nursery as ambassadors and as a role model for aquaculture. For visitors and students, red abalone serve as emissaries for this special type of marine snail. For CMA staff, red abalone provide an excellent teaching tool on the benefits of and need for perfecting aquaculture techniques.
Why red abalone? “Many species of abalone have been overfished along California’s coast and now black and white abalone are both listed as endangered species, but red abalone are still abundant enough to support a recreational fishing season in Northern California,” explained Marissa Velarde, a CMA researcher. “Red abalone also used to be plentiful along Southern California’s coast, but now they are mostly found around the Channel Islands and it’s illegal to fish for them south of San Francisco Bay.”
This cautionary tale demonstrates the consequences of overfishing and also the critical role aquaculture can play in protecting wild stocks. Red abalone also suffer from withering foot syndrome, a disease caused by bacteria that severely weakens abalone making them vulnerable to predation. Abalone in the Aquatic Nursery have tested disease-free 12 times in the last six years! By successfully raising abalone in captivity, there’s no need for fishing with access to healthy stocks, but the concept of aquaculture is still unfamiliar to many people.
“Everyone knows about agriculture, farming and how food is grown, but very few people understand aquaculture and how ocean animals are raised for food,” said Velarde. “By talking about red abalone to visitors and telling their story, the benefits of aquaculture and how it can help reduce fishing pressures becomes much clearer.”
Now, in addition to being ambassadors and aquaculture role models, red abalone have taken on a third role as research subjects in the Aquatic Nursery to help their endangered cousin the white abalone. “Keeping white abalone undisturbed for as long as possible in between breeding attempts is crucial for their ongoing health,” said Velarde. “Red abalone tend to be more resilient and more cooperative when it comes to breeding. We work with red abalone to better understand and breed white abalone.”
A CMA volunteer student researcher successfully raised the first red abalone in the Aquatic Nursery earlier this year. Now Velarde is expanding on that success by testing new research techniques to encourage more red abalone to settle from the larval stage. One hypothesis being tested: What if larvae can chemically detect the slime trails left by adult abalone in the wild and choose to settle in those areas?
“We had adult red abalone crawl in algae and leave their mucus, which is a substance they naturally produce as they are moving and foraging for algae,” explained Velarde. “Then we placed larvae in with the slime and algae. We also placed larvae in with patches of algae without any slime. Now we are waiting to see if more larvae successfully settle where there’s slime.”
If it works, this is a technique that may be used to encourage endangered larval white abalone to settle. So stop by the Aquatic Nursery and talk to CMA staff about this cool project featuring red abalone in a new starring role.
Post Date: Friday, October 12, 2012