Shell carbon isotope indicators of metabolic activity in the deep-sea mussel Bathymodiolus childressi

Abstract

The incorporation of metabolic carbon (C m) into shells of mollusks has been used as an indicator of animal condition and availability of food resources in estuarine and freshwater settings. This study examines C m in Bathymodiolus childressi, a marine cold seep mussel dependent on methanotrophic symbionts. As seeps develop, mature, and go quiescent, methane supply will vary and affect the amount of metabolic carbon deposited into the growing shell. B. childressi (n=136) were live-collected from two seep sites over a 17 year period in the Northern 2 Gulf of Mexico to investigate whether changes in C m were detectable between sites and across years. Significant differences in C m were observed between mussel populations at Brine Pool (15.4±0.4%) and Bush Hill (10.3±0.3%). C m also changed significantly within each site across