Aquaculture 2025

March 6 - 10, 2025

New Orleans, Louisiana USA

MULTISTRESSOR LABORATORY EXPERIMENTS WITH THE ATLANTIC SURFCLAM Spisula solidissima: OCEAN WARMING AND ACIDIFICATION

Laura Steeves*, Rachel Davitt, Shannon Meseck, Ximing Guo, Daphne M. Munroe

 

*Haskin Shellfish Research Laboratory, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, 6959 Miller Avenue, Port Norris, NJ 08349, USA

 

*laura.steeves@rutgers.edu

 



The Atlantic surfclam (Spisula solidissima) is a widely distributed bivalve along the Atlantic coast of the United States and Canada where this species supports a large commercial fishery. Shifts in the distribution of surfclam populations indicates that the Atlantic surfclam is responding to changes in ocean conditions. To examine how changing ocean conditions may impact surfclam growth and survival, laboratory experiments were used to observe surfclam performance at ambient and manipulated levels of temperature and carbonate chemistry (reflective of ocean warming and ocean acidification, respectively). In a flow-through laboratory experiment using natural seawater, surfclams were exposed to one of nine treatments, with three levels of pH and temperature in a fully crossed design. Temperature and pH regimes fluctuated with ambient conditions, while maintaining consistent offsets between each treatment. After six weeks of acclimation, growth, feeding, digestion, respiration rates, and transcriptomics were measured in surfclams from each treatment. Results from this experiment indicate resilience in the Atlantic surfclam to moderate ocean acidification (low pH average = 7.59) across non-stressful thermal regimes (high temperature average = 19.0°C). Surfclams in low pH treatments grew similarly to those in high pH treatments (condition index and shell length), and no differences in metabolic rates were observed across all treatments. The design of this experiment highlights the importance of integrating natural environmental variability into laboratory studies and studying multiple environmental stressors concurrently. These results will help to inform models of surfclam growth and distribution under different climate change scenarios.