UC San Diego

Microfibers in the marine environment pose a threat to aquatic ecosystems and organisms, as well as to humans. Most microfibers are land-based and are transported to the ocean via different processes, including through wastewater effluent and riverine discharge. Measurements of microfiber (MF) concentrations in Southern California coastal surface waters, collected approximately monthly from archived samples between 1983-2019, were available for study and were used in this paper to examine the role of climate in explaining variability in microfiber concentrations. These MF measurements were distinctly non-Gaussian, measuring mostly between 10-50 fibers per 50mL, and showed no seasonal cycle. Time series data was collected for five climate variables (coastal upwelling, precipitation, significant wave height, wind speed, and tidal level), and regression analyses between these variables and MF concentrations were conducted. This study shows that the concentration of microfibers in surface waters in the La Jolla area do not correlate with weather and climate events that presumably would transport microfibers to the marine environment. No more than 1% of microfiber variability can be explained by any variable investigated.