Meredith B. Nevers
Muruleedhara Byappanahalli
Cassie Nelson
Bharath Ganesh Babu
Mary Anne Evans
Eddie Kostelnik
Morgan Keller
Jenna Johnston
Sarah Shidler
Julie R. Peller
2021
<p id="abspara0010"><span>Daunting amounts of microplastics are present in surface waters worldwide. A main category of microplastics is synthetic microfibers, which originate from textiles. These microplastics are generated and released in laundering and are discharged by wastewater treatment plants or enter surface waters from other sources. The polymers that constitute many common synthetic microfibers are mostly denser than water, and eventually settle out in aquatic environments. The interaction of these microfibers with submerged aquatic vegetation has not been thoroughly investigated but is potentially an important aquatic sink in surface waters. In the Laurentian Great Lakes, prolific growth of macrophytic </span><i>Cladophora</i><span> </span>creates submerged biomass with a large amount of surface area and the potential to collect and concentrate microplastics. To determine the number of synthetic microfibers in Great Lakes<span> </span><i>Cladophora</i>, samples were collected from Lakes Erie and Michigan at multiple depths in the spring and summer of 2018. After rinsing and processing the algae, associated synthetic microfibers were quantified. The average loads of synthetic microfibers determined from the Lake Erie and Lake Michigan samples were 32,000 per kg (dry weight (dw)) and 34,000 per kg (dw), respectively, 2–4 orders of magnitude greater than loads previously reported in water and sediment. To further explore this sequestration of microplastics, fresh and aged<span> </span><i>Cladophora</i><span> </span>were mixed with aqueous mixtures of microfibers or microplastic in the laboratory to simulate pollution events. Microscopic analyses indicated that fresh<span> </span><i>Cladophora</i><span> </span>algae readily interacted with microplastics via adsorptive forces and physical entanglement. These interactions mostly cease upon algal senescence, with an expected release of microplastics in benthic sediments. Collectively, these findings suggest that synthetic microfibers are widespread in<span> </span><i>Cladophora</i><span> </span>algae and the affinity between microplastics and<span> </span><i>Cladophora</i><span> </span>may offer insights for removing microplastic pollution.</p><p id="abspara0015">Macroalgae<span> </span>in the Laurentian Great Lakes contain high loads of synthetic microfibers, both entangled and adsorbed, which likely account for an important fraction of microplastics in these surface waters.</p>
application/pdf
10.1016/j.envpol.2021.116695
en
Elsevier
Sequestration of microfibers and other microplastics by green algae, Cladophora, in the US Great Lakes
article