BOTTOM-UP IMPACT OF FRESHWATER MUSSEL DIVERSITY ON BENTHIC ALGAL COMMUNITIES
Mussels and algae have tightly coupled interactions within freshwater ecosystems. Mussel excretion acts as a bottom-up nutrient source for algal communities. Our study examines the impacts of mussel excretion on algal community biomass and composition. We used mesocosms (n=24) to assess algal growth across varying community structure. Four treatments were used: two mussel species (Fusconaia cerina, Quadrula asperata) alone and in combination, and a control. Each treatment was replicated six times. Weekly collection of algal accrual on silicon discs tracked biomass growth over the course of the experiment. Identical samples were simultaneously collected and preserved for community composition analysis. Chlorophyll-a concentration indicates significant differences in algal biomass between the control and two-species treatments as well between Fusconaia treatments and the control. The results show mussel diversity increases algal biomass and that individual mussel species have varying degrees of influence on the algal community, likely caused by differing excretion rates and stoichiometry. These data support the assertion that species richness has positive effects on functional roles within habitats, along with providing insight on bottom-up control in freshwater habitats.
Lauren Shouse (Primary Presenter/Author), The University of Alabama, firstname.lastname@example.org;
Paige Green ( Co-Presenter/Co-Author), University of Alabama , email@example.com;