Larval Exchange in Olympia Oyster Recovery

Recovery of the Native Olympia Oyster, Ostrea lurida, in Northern Puget Sound: Measuring the Larval Import to and Export from a Restored Subpopulation

Researchers will use seawater chemistry to trace larval exchanges between Olympia oyster populations.

Principal Investigator

Bonnie Becker, University of Washington, Tacoma, School of Interdisciplinary Arts and Sciences

Co-Principal Investigators

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


The native Olympia oyster played a key role in Puget Sound’s ecology and economy. But despite cleaner water and an end to commercial harvests, it has failed to reestablish itself. An important question remains unanswered: to what extent does a restored oyster population self-seed, seed other sites, and exchange larvae with other populations? Genetic analysis assesses these connections across multiple generations, but restoration occurs much faster. This project will use the distinctive chemical signatures of seawater at different locations to more speedily and precisely decipher the connections between various Olympia oyster populations.

Research Updates

Washington Sea Grant-funded researchers from three academic institutions partnered with state shellfish managers and growers and a local restoration group to develop a system for tracking movement of larval oysters. Working with undergraduates and colleagues from four oyster farms and two Native tribes, the team applied markers to the shells of larval oysters and tracked movement. More than 14,000 adult females were examined to identify the very small fraction (less than one percent) with shelled larvae that were needed to conduct the analysis.

The team completed field collection and garnered enough samples to validate this approach to planning future sustainable restoration sites. A reference map showing the chemical signature distribution of the shells gathered from throughout Puget Sound will be used to determine the origin of juvenile oysters and measure the distance traveled by larvae. Educational benefits included the contribution of more than 1,000 hours by seven undergraduate students. The project has potential application worldwide.

Annual Reports

2015 Progress Report