Gulf of Alaska | Ecosystem Perspectives DOCTORATE ORAL PRESENTATION Can settlement on coralline algae ameliorate negative effects of ocean acidification and temperature increase on pinto abalone early life stages? Presenter: Eileen Bates , ehbates@uw.edu
Ryan Crim , ryan@restorationfund.org, Puget Sound Restoration Fund Josh Bouma , josh@restorationfund.org, Puget Sound Restoration Fund Caitlin O’Brien , caitlino@restorationfund.org, Puget Sound Restoration Fund Jodie Toft , jodie@restorationfund.org, Puget Sound Restoration Fund
Jacqueline Padilla-Gamino , jpgamino@uw.edu, University of Washington School of Aquatic and Fishery Sciences Pinto abalone, which range from Southeast Alaska, USA, to Baja California, MEX, are a valuable resource for both humans and the complex subtidal ecosystems they inhabit. In Washington State, restoration aquaculture efforts have been underway since 2007 to return the wild population to a critical density where it can become self-sustaining. Restoration groups spawn pinto abalone in the hatchery and rear them for 1-2 years before releasing them to subtidal sites. However, the success of abalone not only depends on restoration efforts but also on the capacity of abalone to survive and reproduce in a changing ocean. In a preliminary hatchery study, we found that pH and temperature influence larval survival, but pH has a stronger effect on settlement success. Our present study aimed to see if crustose coralline algae could increase the success of restoration efforts by serving as a natural settlement inducer in the hatchery and creating a pH refuge for the early stages of pinto abalone. In the hatchery, larval abalone are typically settled on fiberglass using the neurotransmitter GABA, but it is unclear if GABA, as an artificial chemical settlement inducer only present for a few hours, is optimal for the hatchery settlement of abalone. In our study we examined the settlement of pinto abalone under different environmental conditions (7.95pH, 14°C (control); 7.95pH, 18°C; 7.6pH 14°C; and 7.6pH, 18°C) using two substrate types: clean fiberglass with GABA, and CCA covered fiberglass. We tracked the settlement rate and then survival, growth, and substrate microbial composition for the first three months of juvenile growth. If presence of CCA can improve settlement and mitigate effects of ocean acidification on larval and juvenile abalone, we can use this knowledge to improve the efficacy of restoration efforts along the entire range of pinto abalone. Our findings will unblock bottlenecks in the hatchery rearing process and provide insights into ideal wild abalone habitat as climate change increasingly affects the pinto abalone population in Southeast Alaska. These results can help guide efforts in both wild restoration and commercial aquaculture of pinto abalone.
Alaska Marine Science Symposium 2023 32
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