The discovery of endemic communities at deep-sea hydrothermal vents has promoted the question of how these species are able to persist over evolutionary time in isolated, ephemeral vent habitats. One possibility is that larvae and early juveniles of benthic invertebrates are entrained into the buoyant hydrothermal plumes emanating from vents, and are transported to remote vent habitats in lateral plumes, several hundreds of meters above the seafloor. Dr. Mullineaux and associates will examine this hypothesis by sampling larval distributions in hydrothermal plumes and by using hydrodynamic models to predict larval dispersal dynamics. Hydrothermal plumes may also transport reduced substrates (e.g. manganese, iron, methane), microbes, and vent-dwelling zooplankton up into planktonic communities several hundred meters above the seafloor. These scientists will investigate whether zooplankton assimilate chemosynthetically-derived resources, by characterizing their carbon and nitrogen isotopic composition, and by examining their guts for presence of vent-derived mineral precipitates. If the injection of chemosynthetically-fixed carbon into the water column enriches the food resources at level of the lateral plume, then they should find evidence of elevated zooplankton biomass and altered species composition in the plume.
