Meeting Abstract

49-1  Friday, Jan. 6 10:15 - 10:30  All washed up? Mussel survival in the face of ocean warming and acidification CARRINGTON, E*; GEORGE, M; HAYFORD, H; NEWCOMB, L; FRIEDMAN, C; JEFFERDS, I; University of Washington ; University of Washington ; University of Washington ; University of Washington ; University of Washington ; Penn Cove Shellfish LLC

Bivalve mussels are foundational species on many temperate coasts, dominating and structuring mid-intertidal zones. They are also important aquaculture species, sustaining a worldwide industry worth over $1.5 billion annually. The key to the mussel’s success is its ability to anchor to rocks and culture ropes with bungee-like fibers (byssal threads) which dynamically absorb wave energy. Weak attachment leads to mussel dislodgment (fall-off) and ultimately mussel death. Work from our laboratory on Mytilus trossulus has shown mussel byssal thread quality and quantity is lowered by ocean acidification (OA) and warming (OW), weakening overall attachment strength up to 40-80%, respectively. We used our previous biomechanical model for Mytilus edulis in Narragansett Bay, RI to predict how mussel dislodgment would be altered under different "climate-driven" weakening scenarios. Results indicate a nonlinear effect, where small (0-20%) reductions in attachment strength have little impact (80-70%) on annual survival. Large reductions in strength, those expected with OA and/or OW, will reduce mussel survival to 10-60%, levels that may not be ecologically or economically viable. We have also shown attachment responses to OA and OW differs among congener mussel species, and this ecomechanical approach is a useful tool for predicting relative performance of species under different growing conditions, in farmed and natural settings.