DISSERTATION RESEARCH: Underwater soundscapes and their potential role in the settlement of estuarine benthic invertebrates

Most bottom-dwelling marine organisms (e.g. crabs, mussels, corals) develop, zygotes and larvae, in the water column before settling on the sea floor. Reaching an appropriate habitat is critical in determining the distribution and abundance of adults, which make-up marine communities. It has recently been shown that underwater sounds may be an important cue used for marine fish and invertebrate larval in this process, yet the relevant acoustic patterns and associated larval responses remain largely unstudied. Therefore the goal of the research is to understand the nature of underwater sound in larval ecology. This will be done by characterizing an estuarine soundscape and determining how sound variation affects the settlement of invertebrates. The researcher will use larval oysters and clams, and the soundscape of estuarine habitats as a model system, results to date have established that oyster reefs are acoustically distinct from adjacent soft bottom habitats, and that these reef sounds enhance oyster settlement in laboratory experiments. This Doctoral Dissertation Improvement Grant project specifically seeks to expand upon these recent laboratory results by conducting field experiments to test if the apparent larval responses to habitat-related sound operate in the natural environment to shape settlement patterns. Building knowledge of the behavioral responses of marine larvae to bio-physical variables such as sound, and the resulting distribution and abundance patterns of marine organisms is central to improved understanding of marine biology. This work also highlights a potential biological implication of marine noise pollution and may elucidate previously untested benefits of soundscape diversity, ultimately leading to healthier and better-managed ocean and estuary ecosystems.