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Full-Text Articles in Life Sciences
Habitat Associations And Community Interactions Of Non-Native Species In The Southern Basin Of Lake Michigan, Erin O'Shaughnessey
Habitat Associations And Community Interactions Of Non-Native Species In The Southern Basin Of Lake Michigan, Erin O'Shaughnessey
Master's Theses
Non-native crayfishes, mollusks, and macrophytes can have large impacts on biodiversity and damage ecosystem services in freshwaters. In 2015 we discovered an established population of the globally widespread invader red swamp crayfish (Procambarus clarkii) in the North Shore Channel of the Chicago Area Waterway System. This population overlaps with a population of rusty crayfish (Faxonius rusticus), a previous invader that is widely distributed and usually the dominant crayfish species across the Great Lakes region. I studied the interactions between these two species while directly competing over shelter and food. In the field, each species was studied to determine the rate …
Microplastic In Aquatic Food Webs: Museum Specimens And Ingestion Experiments Reveal Controls On Microplastic Ingestion By Freshwater Fish, Loren Hou
Master's Theses
Plastic is pervasive in modern economies and ecosystems. Early research suggests freshwater fish commonly ingest microplastic (particles < 5 mm), which may influence fish digestive tissues, but no studies have examined historical patterns in microplastic consumption or rates of microplastic retention in fish. We measured microplastic in digestive tissue of specimens collected and preserved over the last century (Field Museum, Chicago). We selected Micropterus salmoides (largemouth bass), Notropis stramineus (sand shiner), Ictalurus punctatus (channel catfish), and Neogobius melanostomus (round goby) because each was well represented in the museum collection, with specimens from urban rivers. Specimens from 1900-2018 showed increases in microplastic concentration from the 1950's to present. in a second project, we collected round gobies from Lake Michigan in Chicago to conduct feeding experiments to measure microplastic ingestion and retention rates. the majority of microplastic was excreted within 72 hours of ingestion. Results will aid in understanding ecological interactions of microplastic and freshwater fish, informing further work on the movement of microplastic in aquatic food webs.