Oregon Sea Grant

A massive reduction in historic populations of Olympia oysters (Ostrea lurida), the only native oyster found on the west coast of North America, has contributed to a loss of ecosystem and cultural services once provided by this species. Resource management agencies and environmental organizations are working to protect and enhance the remaining populations, but in many locations, information to characterize the current geospatial distribution of Olympia oysters is lacking. Advances in mapping technology and increased availability of geospatial, ecological data allow for more effective tracking and monitoring of Olympia oysters, which can support protection efforts. However, resource management agencies often face financial and staffing constraints that limit their ability to inventory the species across its range. Habitat Suitability Modeling (HSM) provides a promising approach for making predictions about the geospatial distribution of wild Olympia oyster populations by understanding and analyzing the physical environmental variables that influence its specific habitat.

This project evaluates the use of an HSM, developed using geospatial raster layers of salinity, substrate, and elevation, in Yaquina Bay, Oregon to predict locations of Olympia oyster presence. This study was unable to make a conclusive determination regarding the predictive capacity of the HSM due to a small number of field samples. Recommendations are provided for expanding the HSM and supporting several other management applications, including characterizing the abiotic and biotic attributes of the habitat occupied by Olympia oysters and identifying biological monitoring sites.