October 1, 2017.
Sea star wasting disease (SSWD) has affected many asteroid populations on the Pacific Northwest coast in recent years. Because sea stars are keystone predators, the absence of them can severely alter the structure of intertidal communities. As populations diminish, it is important to understand what the preferred prey of sea stars is and how prey preference may affect distribution and abundance of sea stars. This laboratory study examined the prey preference of Leptasterias populations from Friday Harbor, Washington, Humboldt County, California, and Pigeon Point, California. The purpose of the study was to 1) determine if sea stars have a preferred prey type, 2) determine if there is a difference in prey preference across different populations, and 3) determine if there is a difference in prey preference between sea stars of different microhabitats (i.e. in pools or attached to rocks within the intertidal). To assess this, multiple binary choice trials were conducted in which sea stars were offered different prey types of equal accessibility. Preference was determined by calculating the average position of sea stars in an experimental tank. Preliminary observations suggest that there is a difference in prey preference between stars of different populations and microhabitats, however statistical analyses are needed at this time. Future studies are necessary that include larger sample sizes, a more controlled laboratory environment, and field-based experiments and observations.
Romberg Tiburon Center for Environmental Studies (RTC)
The 2017 STEM Teacher and Researcher Program and this project have been made possible through support from Chevron (www.chevron.com), the National Marine Sanctuary Foundation (www.marinesanctuary.org), the California State University Office of the Chancellor, and California Polytechnic State University, in partnership with Romberg Tiburon Center.