Larval Exchange in Olympia Oyster Recovery
Researchers will use seawater chemistry to trace larval exchanges between Olympia oyster populations.
Bonnie Becker, University of Washington, Tacoma, School of Interdisciplinary Arts and Sciences
Brian Allen, Puget Sound Restoration Fund
Henry Carson, Washington Department of Fish and Wildlife
Betsy Peabody, Puget Sound Restoration Fund
Andrés J. Quesada, Northwest Indian College, Salish Sea Research Center
Brent Vadopalas, University of Washington, School of Aquatic and Fishery Sciences
Washington Sea Grant-funded researchers partnered with tribes, shellfish managers and a local restoration group to determine how far Olympia oyster larvae disperse. From 2015 to 2016, the researchers collected planktonic larvae and recent settlers, and sampled over 14,000 adults throughout Puget Sound to collect brooded larvae from more than 100 oysters using a novel sampling method that is non-lethal to the parent animal. The researchers then examined the larvae using elemental fingerprinting, a technique that measures the elemental makeup of the animal’s shell, which reflects the environment in which that shell was formed.
Washington’s only native oyster, the Olympia, was overharvested starting in the 1850s, resulting in its depletion. Despite protections instituted by state agencies, the species has yet to recover. Olympia restoration is now a regional priority whose success relies on reestablishing self-sustaining populations that can replenish surrounding beds. Information about how far Olympia larvae disperse in Puget Sound could aid these restoration efforts.
In 2018, the researchers continued to comb through their elemental fingerprinting results to understand how far the larvae had dispersed, applying various statistical methods to determine the correct scale for their analysis. This is the first use of elemental fingerprinting of an invertebrate in Puget Sound and will help validate whether this is an effective approach for managing and conserving shelled species in the region. Restoration professionals may be able to use this data to understand which sites present the best opportunity for Olympia oysters to become self-sustaining and a potential source of offspring for nearby sites.