The effect of rocky intertidal foundation species loss on tidepool biogeochemistry and microbiomes

Foundation species create shelter, enhance biodiversity, and maintain ecosystem functioning within their environment. Within the rocky intertidal ecosystem, a coastal ecosystem dominated by mussels and surfgrass, foundation species are expected to decrease in abundance with climate change, extreme climatic events, and increased human impact. However, there is a need to better understand how foundation species loss will affect ecosystem functioning through changes in biogeochemical cycling, thermal buffering, microbial community composition, and ecosystem metabolism. Using tide pools in coastal Oregon as a study system, we will test how the loss of mussels (Mytilus californianus) and surfgrass (Phyllospadix spp.) affect biogeochemistry, thermal buffering, microbial communities, and ecosystem metabolism (net ecosystem calcification [NEC] and net ecosystem production [NEP]) using a Before-After-Control-Impact (BACI) experimental design. This study will anticipate immediate cascading impacts of foundation species loss on ecosystem function to aid in conservation management policies of our intertidal ecosystems.