Distributed from Baja California to Alaska, the red sea urchin (Mesocentrotus franciscanus) is both ecologically and commercially important. As ecosystem engineers, red urchins control algal abundances in kelp forest ecosystems. They are also the primary urchin species harvested for gonads or “uni” in California. Recently, M. franciscanus abundance has declined dramatically due to fishing in the last few decades; in addition, warmer water temperatures are thought to cause increased disease and mass mortality events. Despite its importance and vulnerability, little is known about M. franciscanus’ ability to respond to prolonged temperature stress.

Furthermore, marine heatwaves (MHWs) are predicted to increase drastically in frequency, duration, range, and intensity due to anthropogenic climate change. With such forecasts and red urchin populations already on the decline, it is important to determine if future generations can rapidly adjust their phenotypes for survival in future MHWs on the California coast. The question then arises: what is the impact of future MHWs on red urchins, and further can they be resilient to future heat stress events?

This project will assess whether the thermal history of adult red urchins from the Santa Barbara Channel influences the thermal tolerance of their progeny and how MHWs and food availability affect gonad quality. Results will reveal the adaptive capacity of M. franciscanus and the mechanisms by which the red urchin can rapidly adapt to MHWs. They will also indicate how MHWs and food availability may interact to affect fishery success. Outcomes may be utilized by stakeholders to predict the climate readiness of the fishery and create adaptive management plans.

Lead Researchers: Erin de Leon Sanchez and Hofmann Lab

Location: Santa Barbara, CA

Support/Funding: California Sea Grant, UCSB Coastal Fund

Partners: California Department of Fish and Wildlife, California Sea Urchin Commission, UCSB Research Experience and Education Facility (REEF), Channel Islands National Marine Sanctuary, National Park Service

Opportunity: n/a

Community Participation: Come see the red urchins on display at the UCSB REEF!