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Full-Text Articles in Life Sciences
Anthropogenic Particle (Including Microplastic And Microfiber) Transport And Retention In Streams Under Varied Environmental Conditions, Elizabeth Marjorie Berg
Anthropogenic Particle (Including Microplastic And Microfiber) Transport And Retention In Streams Under Varied Environmental Conditions, Elizabeth Marjorie Berg
Master's Theses
Microplastics (plastic particles <5 mm) and other anthropogenic particles (i.e., synthetic, semi-synthetic and anthropogenically modified cellulose particles < 5mm) are pollutants of concern in aquatic ecosystems worldwide. Anthropogenic particles enter food chains, adsorb harmful chemical pollutants, and are ubiquitous in aquatic ecosystems. Streams are key sites of anthropogenic particle input, retention, and transport, and empirical measurements of particle movement in lotic ecosystems are needed to inform global budgets of anthropogenic particles and microplastics. However, factors that influence anthropogenic particle retention in lotic ecosystems are poorly understood. We demonstrate how environmental characteristics affect plastic transport and retention in streams in experimental and observational studies. In our experimental study, we used particle spiraling metrics to directly measure microplastic retention in outdoor, experimental streams at Notre Dame's Linked Experimental Ecosystem Facility (ND-LEEF). We tested the impact of stream discharge (i.e., high, low), benthic biofilms (i.e., well-established biofilms, reduced biofilms post-scouring), and benthic substrate type (i.e., cobble, pea gravel, sand, mixed substrate) on retention of microplastic fibers using pulsed releases and synchronized water sample collection at 3 sites downstream. We also collected benthic surface samples for biomass and microplastic density. Samples were filtered directly (water samples) or after peroxide digestion (benthic samples), and experimental microplastic fibers were enumerated visually using a dissecting microscope. Microplastic deposition rates were significantly higher with (1) higher discharge, (2) well established benthic biofilm (as opposed to bare substrate), and (3) larger and more homogeneous substrates. The observational study examined anthropogenic particles (including microplastics and microfibers) in the Milwaukee River during storm events. Lotic ecosystems are highly variable (e.g., seasonal changes, storm events), and most research assessing anthropogenic particle pollution extrapolates stream particle loads based on measurements during only one point in time. This limits the accuracy of anthropogenic particle and microplastic dynamics models in rivers, where frequent changes in discharge drives retention and transport of fine particles. In this study, we used automated samplers to collect water from the Milwaukee River during four distinct storm events in the spring and summer of 2018. We quantified anthropogenic particle abundance using standard methods and used nearby USGS gauges to determine discharge. Anthropogenic particle concentrations varied significantly among the four sampling periods, highlighting the temporal variability of anthropogenic particle transport across dates. When data from the sampling periods were pooled, there was a decrease in anthropogenic particle concentration in the water column after storm events, indicating that floods may "flush" microplastics from the river. Unexpectedly, anthropogenic particle concentrations were not correlated with other water quality metrics, including concentrations of total suspended solids, fecal coliform, chloride, nitrate, and sulfate, indicating that these metrics cannot be used to estimate microplastic concentrations and likely have distinct driving factors. These results provide novel insights into the environmental factors controlling anthropogenic particle and microplastic fate and are critical to understanding the role of lotic retention and transport in global plastic budgets.
Microplastic In Riverine Fish Is Connected To Species Traits, R. E. Mcneish, L. H. Kim, H. A. Barrett, S. A. Mason, J. J. Kelly, T. J. Hoellein
Microplastic In Riverine Fish Is Connected To Species Traits, R. E. Mcneish, L. H. Kim, H. A. Barrett, S. A. Mason, J. J. Kelly, T. J. Hoellein
Biology: Faculty Publications and Other Works
Microplastic is a contaminant of concern worldwide. Rivers are implicated as major pathways of microplastic transport to marine and lake ecosystems, and microplastic ingestion by freshwater biota is a risk associated with microplastic contamination, but there is little research on microplastic ecology within freshwater ecosystems. Microplastic uptake by fish is likely affected by environmental microplastic abundance and aspects of fish ecology, but these relationships have rarely been addressed. We measured the abundance and composition of microplastic in fish and surface waters from 3 major tributaries of Lake Michigan, USA. Microplastic was detected in fish and surface waters from all 3 …
Anthropogenic Litter And Microplastic In Urban Streams: Abundance, Source, And Fate, Amanda Rae Mccormick
Anthropogenic Litter And Microplastic In Urban Streams: Abundance, Source, And Fate, Amanda Rae Mccormick
Master's Theses
The accumulation and ecological effects of anthropogenic litter (AL) and microplastic are well-documented in marine ecosystems, but these materials’ abundances in rivers is unknown. AL enters rivers from recreation, runoff, and illegal dumping. Microplastic fibers and pellets are abundant in wastewater treatment plant (WWTP) effluent which enters rivers. Our objectives were to: (1) quantify AL abundance and composition in urban streams, (2) measure AL flux, accumulation, and export, and (3) measure riverine microplastic concentration and analyze its bacterial communities. We collected AL from 5 urban streams and observed greater AL density in riparian habitats and greater mass in benthic habitats. …