Effects of Ocean Acidification on Lottia scutum Settlement

Abstract

The effects of ocean acidification on calcifying marine organisms are becoming more pronounced as atmospheric CO2 levels have increased due to anthropogenic carbon emissions (Etheridge et al., 1996). Studies on these effects have also increased over time. Ocean acidification (OA) has been shown to affect the feeding behavior and metabolic rates of larvae in a number of species (Vargas et al., 2013; Pan et al., 2015). Metabolic changes can significantly influence developmental rates, but little is still known about consequences of OA for non-feeding marine invertebrate larvae. In this study, we focus on the effects of OA conditions on the larval stage of Lottia scutum, a Pacific rocky intertidal limpet species that ranges from Alaska to southern California. Larvae were exposed to OA conditions (pH 7.3) at competency stage and monitored for settlement behavior and metamorphosis. Our results indicate that L. scutum larvae were able to successfully settle in OA and ambient seawater treatments. We did not find a negative effect of the specific OA conditions used in this study on the settlement of L. scutum. These findings provide insight into how environmental stress might affect early life stages, as well as how marine invertebrate larvae from regularly low pH environments fare in OA conditions.