Influence of burrowing macroinvertebrates and invasive filter-feeding mussels on nutrient biogeochemistry in eutrophic lake sediments
Eutrophication can affect the function and structure of benthic invertebrate communities, which are essential components of a lakes ecology. Post-doctoral researcher Dr. Geraldine Nogaro is especially interested in the influence of nutrient enrichment on the competitive interactions between benthic insect larvae that are active in bioturbation (i.e., all burrowing, feeding, irrigating, and respiratory activities induced by benthic fauna within the sediment) and the invasive dreissenid mussels (i.e., zebra and quagga mussels), which obtain their food by filter-feeding from the water column. It is anticipated that the invasion of the mussels has influenced the biodiversity and bioturbation activities of native aquatic insect larvae, such as burrowing chironomids. These impacts on chironomid larvae may affect critical ecological processes in lakes, such as organic matter mineralization and nutrient cycling.
The main objective of Dr. Nogaro's project is to determine how the activities of burrowing chironomids and invasive mussels will interact with lake sediment characteristics (i.e., organic matter content) to influence the biogeochemical fluxes and water quality in eutrophic lake environments. This will be accomplished through laboratory mesocosm experiments using Plexiglas cores (30 cm height, 7 cm diameter) filled with sediment and water taken from Bear and Muskegon Lakes. The results from this project will provide new information about the biogeochemical functioning of Bear and Muskegon Lakes and in general, eutrophic freshwater ecosystems. This research will also provide important information about the ecological influence of dreissenid mussels, ecosystem-disrupting invasive organisms in the Great Lakes.