Microplastics and microfibers in surface waters of Monterey Bay National Marine Sanctuary, California

• Published in: Marine pollution bulletin Vol. 165; p. 112148
• Main Authors: Kashiwabara, Lauren M., Kahane-Rapport, Shirel R., King, Chad, DeVogelaere, Marissa, Goldbogen, Jeremy A., Savoca, Matthew S.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-04-2021; Elsevier BV
• Subjects: Baseline studies; Bays; California; Environmental Monitoring; Marine debris; Microfibers; Microplastics; Monterey Bay; Nature conservation; Offshore; Plastic debris; Plastic pollution; Plastics; Pollution; Polyethylene; Polyethylenes; Polymers; Polypropylene; Sanctuaries; Seamounts; Surface seawater; Surface water; Water Pollutants, Chemical - analysis; Water transportation; Wildlife sanctuaries; California; Monterey Bay; Microplastics; Surface seawater; Monterey Bay; Microfibers; Marine debris
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2021.112148

Despite a recent report of high concentrations of microplastics and microfibers in the mesopelagic waters of Monterey Bay National Marine Sanctuary (MBNMS), little is known about these particles in surface waters. From 2017 to 2019, we sampled two nearshore and two offshore locations within MBNMS using a manta trawl and analyzed these samples for microplastics and microfibers. We found an average concentration of 1.32 ± 0.70 (SE) particles per m3. We found the highest concentration of particles closest to shore, and the lowest concentration above the remote Davidson Seamount. Fiber-like debris was more common in offshore, as compared to nearshore, sites. Overall, particles in our samples were primarily buoyant synthetic polymers, including polypropylene and polyethylene. Our results provide baseline data on the degree of microplastic and microfiber pollution in MBNMS surface waters and confirm that this pollution can be found in waters from the surface to at least 1000 m depth.
•First extensive sampling of MBNMS surface water for microplastics and microfibers (i.e., ‘particles’).•Nearshore Santa Cruz had highest concentrations (3.21particles/m3); offshore Davidson Seamount had lowest (0.26 particles/m3)•There was a higher proportion of microfibers at offshore sites compared to nearshore sites.•Polypropylene and polyethylene were most common polymers identified using FTIR.•Overall, concentrations (1.32 particles/m3) were similar to other studies of surface seawater both regionally and globally.