A collaborative partnership to address mass mortalities in oyster aquaculture through improved field monitoring, husbandry practices, and workforce development

As a collaborative partnership, the collective goal is to ensure the sustainable expansion of oyster aquaculture within Washington state by reducing the frequency and severity of mass mortality events that result from the interaction between OsHV-1 infection and extreme climate events such as marine and aerial heatwaves. The specific research and outreach objectives of this project are 1.) determine the susceptibility of Washington shellfish farms to heatwaves; 2.) develop a commercially viable hatchery husbandry protocol that improves oyster heat tolerance; and 3.) generate an enhanced workforce training curriculum that uses OsHV-1 and heat waves as case studies. Students will also gain exposure to training opportunities by serving as hatchery technicians, summer interns at shellfish farms, and student ambassadors during regular partner meetings.

Project background

The anticipated arrival of the viral pathogen Ostreid herpesvirus 1 (OsHV-1) within the coastal and inland waters of Washington state represents an existential threat to shellfish aquaculture. Viral outbreaks triggered by a warming ocean are expected to generate catastrophic oyster mortality events due to their co-occurrence with episodic periods of low survivorship (i.e., summer mortality) and extreme climate events (i.e., marine and aerial heat waves). This project forms a collaborative partnership made up of academic (UW: University of Washington, BTC: Bellingham Technical College, Maritime High School), industry (Taylor Shellfish Co., Nisbet Oyster Co., Westcott Bay Shellfish Co.), federal (USDA, NOAA), and tribal (Jamestown S’Klallam Tribe) stakeholders who have the knowledge, expertise, and resources to safeguard aquaculture production by improving the climate tolerance of OsHV-1 resilient oyster lines currently being developed by the USDA.

Results and findings

The team is conducting a series of coordinated field and lab experiments aimed at improving oyster resilience to environmental stressors, particularly thermal extremes. The two experiments tested how different heat priming, or hardening, strategies in the hatchery at various life stages affect adult oyster survival, growth, and physiological responses under real farm conditions. Two types of heat priming in the hatchery were tested: daily mild heat and weekly strong heat. Oysters were then outplanted and tracked for survival and growth for 18 months.

Preliminary results indicate that farm management (density, site, timing) likely matters more than early-life heat exposure for optimizing growth and survival. Priming did, however, impact oyster capacity for survival under acute lab stress testing and may prove more influential during extreme marine heat waves. This project is ongoing.

Contact information

Emily Carrington
Professor
Department of Biology, University of Washington
201.221.4676
ecarring@uw.edu