Ecological connectivity in Pacific deep-sea hydrothermal vent metacommunities

Larval dispersal and connectivity between patchy, transient, deep-sea hydrothermal vent communities are important for persistence and recovery from disturbance. We investigated connectivity in vent metacommunities using the taxonomic similarity between larvae and adults to estimate the extent of exchange between communities and determine the relative roles of larval dispersal and environmental limitations (species sorting) in colonization. Connectivity at vent fields in 3 Pacific regions, Pescadero Basin, northern East Pacific Rise (EPR), and southern Mariana Trough, varied substantially and appeared to be driven by different processes. At Pescadero Basin, larval and adult taxa were similar, despite the existence of nearby (within 75 km) vent communities with different species composition, indicating limited larval transport and low connectivity. At EPR, larval and adult taxa differed significantly, despite the proximity of nearby vents with similar benthic composition, indicating substantial larval transport and potentially strong species sorting, but other factors may also explain these results. At the Mariana Trough, the larvae and adults differed significantly, indicating high larval transport but environmental limitations on colonization. We demonstrate that analysis of routinely collected samples and observations provides an informative indicator of metacommunity connectivity and insights into drivers of community assembly.