Meeting Abstract

21.7  Saturday, Jan. 4 15:00  Shell damage and repair in the bay mussel under a range of pCO2 conditions GEORGE, M*; O’DONNELL, M; CARRINGTON, E; University of Washington, Seattle, WA 98105; California Ocean Science Trust, 1330 Broadway Ave Suite 1530 Oakland, CA 94612; University of Washington, Seattle, WA 98105 mngeorge@uw.edu

Shell damage is a threat for mussels (Mytilus) living on rocky shores. One source is predatory snails (Nucella) which use a serrated tongue to drill through the shells of bivalves. However, this method of predation is often interrupted in nature, leaving mussels with shell damage, resulting in the loss of body fluids and infection by parasites. In response mussels rapidly repair damage to maintain homeostasis. Previous studies in our lab have shown that this repair process represents a significant cost to the mussel. With this in mind, we explored whether future oceanic conditions which result from climate change will act as an added stressor on the repair process. Consistent shell damage was produced across a group of mussels and shell repair was monitored within experimental seawater mesocosms with a range of pCO₂ concentrations (400 – 2500 µatm) for a 2 month period. Shell repair was quantified using both a visual scoring method and microCT scans of intact shells. Variation in shell repair was seen across treatments with no observable impact of increased pCO₂. A consistent progression of shell repair was seen, with mussels filling in holes with an organic matrix which then slowly hardened and turned white over the course of weeks. MicroCT analysis of density within the repair region implies the repair region was not calcified over the course of the experiment, regardless of treatment. Shell repair appears to be an energy intensive process of high priority at the onset of shell damage. However, it remains unclear how long it takes to produce material which mimics undamaged shell, if such an endpoint is even possible.