Workshop highlights urgency of abalone recovery efforts

April 2016

 

In January, scientists, aquarists, educators, industry representatives, and resource managers convened to explore the future for abalone recovery, particularly white abalone which is critically endangered. The focus of the workshop was to share information among partners who are working to recover abalone through a captive breeding program. The information gathered from the workshop will be used to inform best practices and guide future recovery efforts.

White abalone is one of seven abalone species found along the U.S. West Coast. This species is critically endangered primarily because of historical harvesting practices, and today it is recognized by NOAA Fisheries as one of eight species most at risk of extinction nation-wide. As part of the agency’s initiative to recover white abalone, NOAA Fisheries released an updated recovery roadmap in February 2016. The plan outlines five key actions that are needed to recover white abalone, including several that were main topics at the workshop.

Checking abalone gonad index prior to a spawning event at the Bodega Marine Lab. Photo: Kristin Aquilino, UC Davis

The two-day workshop covered each step in the captive breeding program— beginning with spawning adult abalone in the lab to placing them into the ocean as a way to boost wild populations (outplanting). A broad range of presenters shared research, techniques, and tricks of the trade for each of these topics. Among the presenters were abalone farmers who have been raising red abalone commercially for over 30 years.

Capturing sperm from a male white abalone during a spawning event at the UC Davis Bodega Marine Lab. Photo Joshua Asel, UC Davis

One of the issues discussed by workshop participants is the difficulty in getting some abalone to spawn in the lab. Researchers are trying to understand the environmental cues that lead to better spawning success. The Bodega Marine Lab at University of California Davis is testing whether mimicking seasonal changes in the lab will make a difference in abalone spawning performance. This is accomplished by changing light exposure to mimic seasons and create a more natural environment.

Juvenile white abalone at two months of age. Photo: Kristin Aquilino, UC Davis

Research gaps were identified, but an area that stood out as important to study in the near-term relates to post-larval settlement. The post-larval settlement period is when abalone mature from the larval stage— floating in the water— to settling on a rocky substrate. This is a critical time during the life of young abalone—a time when mortality rates are very high based on our observations of abalone in captivity. Scientists are going to explore ways to reduce some of this mortality in the lab by testing optimal settlement conditions using different chemical cues and physical substrates. Maximizing the genetic diversity of captive-bred abalone may help promote better survival of young settlers in captivity and in the wild. Abalone are also very small and cryptic just after settlement, so it is challenging for researchers to assess survivorship at this stage. Researchers are working on monitoring methods to detect these tiny, young abalone in captivity and in the wild once outplanting efforts are underway.

Another key finding is that the timing for white abalone recovery continues to be an urgent matter. One of the presenters, Dr. Cynthia Catton from the California Department of Fish and Wildlife, discussed a population model she and colleagues developed to estimate when white abalone would go extinct if efforts to place captive-raised abalone into the wild were not initiated promptly. The model predicted that the population may reach a point of no return soon based on the steady decline of one wild white abalone population that has been monitored for over a decade. Natural recovery is likely not taking place because white abalone are too far apart from one another to reproduce in the wild. This work will be published soon in the Journal of Shellfish Research Special Publication of the International Abalone Symposium.

“Throughout this workshop we heard that there is still a lot of work to do, but after meeting with all of the partners we have a much better idea of what the future could look like for the recovery of white abalone,” says Dr. Melissa Neuman, Recovery Coordinator for NOAA Fisheries West Coast Region, Protected Resources Division.

In early March, the most successful captive spawning in the history of the white abalone program occurred at the Bodega Marine Lab. Two of the aquaria partners—Aquarium of the Pacific in Long Beach, and Cabrillo Marine Aquarium in San Pedro are gearing up for white abalone spawning attempts in April. This offers another opportunity for collaboration among workshop participants to share and refine spawning techniques. With the program’s increased success, we are getting our captive white abalone primed and ready for their introduction into the kelp forests of Southern California!

LEARN MORE…

White Abalone status and reports

http://www.westcoast.fisheries.noaa.gov/protected_species/abalone/white_abalone.html

Partnerships and Innovation Contribute to Recovery

http://www.westcoast.fisheries.noaa.gov/stories/2015/22_01222015_abalone.html

Home page photo of White abalone juveniles at the UC Davis Bodega Marine Lab by Joshua Asel, UC Davis