Short- And Long-Term Micro & Nano Particles Exposure to Estuarine Model Species at Variable Salinities

Micro (< 5mm) & Nano (1-1000 nm) plastic (MNP) particles are ubiquitous in the environment and have been shown to have a variety of effects on aquatic organisms. The effects of MNP exposure can vary depending on the type of MNP, the concentration of MNP, the duration of exposure, and the salinity of the water. This study used 5 plastic types including polyester (PE), polypropylene (PP), polylactic acid (PLA), polyethylene terephthalate (PETE) and tire particles (TP) in two forms, solid plastic particles and microfibers. To assess potential impacts on exposed organisms, early life stages of the estuarine indicator species Inland Silverside (Menidia beryllina) and mysid shrimp (Americamysis bahia) were exposed to three concentrations at micro- and nano-size fractions, and separately to leachate, across a 5-25 PSU salinity gradient. This exposure study was performed in longer term (21 days for Inland Silverside and 28 days for mysid shrimp) and shorter term (4 days for Inland Silverside and 7 days for mysid shrimp). Following MNP exposures of 7d (A. bahia) and 96 h (M. beryllina), behavioral assays were performed post-exposure from each treatment using a Danio Vision Observation Chamber (Noldus, Wageningen, the Netherlands) for the dark: light cycle as described previously (Siddiqui et al., 2022; Siddiqui et al., 2023; Mundy et al., 2021; Segarra et al., 2021). These behavior studies provide important information for risk assessments and policy making that can establish knowledge for MNPs risk.