Microplastic contamination in the San Francisco Bay, California, USA. Marine Pollution Bulletin 109 . SFEI Contribution No. 769.2016.
Despite widespread detection of microplastic pollution in marine environments, data describing microplastic abundance in urban estuaries and microplastic discharge via treated municipal wastewater are limited. This study presents information on abundance, distribution, and composition of microplastic at nine sites in San Francisco Bay, California, USA. Also presented are characterizations of microplastic in final effluent from eight wastewater treatment plants, employing varying treatment technologies, that discharge to the Bay. With an average microplastic abundance of 700,000 particles/km2, Bay surface water appears to have higher microplastic levels than other urban waterbodies sampled in North America. Moreover, treated wastewater from facilities that discharge into the Bay contains considerable microplastic contamination. Facilities employing tertiary filtration did not show lower levels of contamination than those using secondary treatment. As textile-derived fibers were more abundant in wastewater, higher levels of fragments in surface water suggest additional pathways of microplastic pollution, such as stormwater runoff.
Applying Sediment Quality Objective Assessment Protocols to Two San Francisco Bay 303(d)-Listed Sites. Final Report. San Francisco Estuary Institute: Richmond.2013.
Applying Sediment Quality Objective Assessments to San Francisco Bay Samples from 2008-2012. San Francisco Estuary Institute and Southern California Coastal Water Research Project: Richmond, CA.2013.