One of the largest “sinks” for engineered nanoparticles (ENPs) released into the natural environment will be saltwater ecosystems. While colloidal stability theory suggests that high salinity concentrations will cause ENPs to aggregate, the diverse group of biogenic polymers present in these ecosystems may cause radically different ENP behavior. A Research Opportunity is available to help investigate the fate, transport, and bioavailability (including trophic transfer) of model ENPs under environmental relevant conditions. Associates will have access to state-of-the-art characterization and surface analysis facilities, a world-class aquatic species rearing center, and collaborators at NIST and the Center of Marine Biotechnology (COMB) with experience in these respective areas. It is envisioned that the Associate will apportion their time between NIST and COMB as needed.