Access Type

Open Access Dissertation

Date of Award

January 2022

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Biological Sciences

First Advisor

Donna R. Kashian

Abstract

Asian clams (Corbicula spp.), zebra and quagga mussels (Dreisenna spp.) have invaded and spread throughout North American surface waters. Corbicula and Dreisenna species bio foul aquatic systems, occupy benthic substrates and degrade environments through shell deposition. I explored how Dreissena and Corbicula invasions affect benthic fish and macroinvertebrate communities, and examine how their impacts differ between urban and rural systems, and temperate and tropical climates. Macroinvertebrate and fish communities were evaluated at sites with increasing shell densities in the Rouge, and Huron rivers (MI, USA) using the United States Environmental Protection Agency’s Rapid Bioassessment Protocols (RBP). Urban and rural macroinvertebrate communities were compared by installing in situ colonization racks with Dreissena shell/cobble treatments of 100/0%, 75/25%, 25/75%, and 0/100% in urban and rural river reaches of the Rouge, Clinton and Huron rivers. I evaluated the impacts of Corbicula on macroinvertebrate communities in rivers in four climate regions including Michigan, Ohio, Georgia and Puerto Rico. All benthic community data was evaluated using water quality, diversity and habitat metrics. In the RBP assessment of the Rouge and Huron rivers, I found that that relative abundance of sensitive macroinvertebrates decreases as Dreissena shell densities increase in both rivers. Benthic fish were not significantly impacted as shell densities increased in either river. In rural reaches of the Huron River, fewer sensitive macroinvertebrate families colonized high density shell treatments when compared to cobble; conversely, macroinvertebrate community diversity was elevated in high shell densities when compared to low densities in urban reaches of all three rivers. The impact of increasing Corbicula population densities differed as macroinvertebrate diversity and evenness increased with population density in the temperate, Michigan climate and decreased as clam densities increased in tropical Puerto Rico. These findings indicate that bivalve invasions can have deleterious impacts on sensitive macroinvertebrates in urban and rural settings but can provide habitat for urban communities. Although temperate macroinvertebrates favor dense bivalve invasions in northern climates, declines in diversity and evenness in the south may foreshadow responses as surface water temperatures increase. This data could help management groups anticipate the impacts of invasive bivalves on native faunal communities.

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