IntroductionConnectivity refers to the degree to which organisms from spa-tially separated groups within a species mix during their lifespan.Understanding connectivity in marine fish provides insight intothe level of gene flow (e.g. local adaptation) among subsets ofthe population and the degree of self-recruitment within sub-sets either due to larval retention near natal habitat (e.g. Sweareret al., 1999) or natal homing (e.g. Thorrold et al., 2001). Identi-fying population structure allows predictions about the ability ofpopulation subsets to occupy new habitats, the long-term stabilityof population dynamics (e.g. Schindler et al., 2010) and effec-tive protected area design (Di Franco et al., 2012). Connectivity isoften difficult to determine in marine fish that have a high dis-persal potential as planktonic larvae and/or are highly migratory asadults. To overcome this challenge, scientists have used the chem-istry and structure of otoliths, or ‘earstones’, as natural tags of∗