Sampling and Analysis Plan for Microplastic Monitoring in San Francisco Bay and Adjacent National Marine Sanctuaries: FINAL.

Abstract

Plastic in the ocean, and more specifically microplastic (particles <5 mm), has been gaining global attention as a pervasive and preventable threat to the health of marine ecosystems. Microplastic is ingested by marine organisms (Wright et al. 2013), and may impact their physiological processes (von Moos et al. 2012; Cole et al. 2013, 2015; Rochman et al. 2013, 2014b; Wright et al. 2013; Watts et al. 2015; Lu et al. 2016; Sussarellu et al. 2016). Microplastic may also contain harmful chemicals such as flame retardants, plasticizers, or dyes (Browne et al. 2013; Fries et al. 2013; Rochman et al. 2013, 2014a,b), and may provide a substrate for the adsorption of other harmful chemicals in the ocean, like PCBs and DDT (Teuten et al. 2007), which then may be transferred up the food chain (e.g., Farrell and Nelson 2013; Rochman et al. 2014a; Setala et al. 2014). Many scientific questions remain, however, and there is a need for research on the patterns of distribution and uptake of microplastic by organisms in their ocean ecosystems. These scientific gaps also exist for San Francisco Bay, where basic questions remain unanswered, such as where, when, and how is microplastic entering the Bay and what circulation patterns deliver them to the ocean. The use of plastic in modern society is ubiquitous; as a result, the pathways by which microplastic reach the Bay, its transport and distribution throughout the Bay, and the levels to which it is taken up into the food web are complex. A preliminary study of nine surface water sites in Central Bay and South Bay showed greater levels of microplastic than in either the Great Lakes or Chesapeake Bay (Sutton et al. 2016). Understanding this stressor is important not only to the health of the Bay, but to the adjacent ocean. In addition, understanding the dynamics of this issue from a scientific perspective is critical to informing and motivating effective policy solutions, interventions, and innovations at the waste treatment, individual behavior, and industrial design level. Current policies that govern wastewater and stormwater treatment processes and current definitions of pollution are inadequate to address this growing and widespread threat. Data are essential to understanding and minimizing the impacts of microplastic on San Francisco Bay and the adjacent ocean. To develop critical baseline data and inform solutions, the Gordon and Betty Moore Foundation has awarded the San Francisco Estuary Institute and The 5 Gyres Institute a grant for $880,250 to complete a series of studies over 2 years, including water, sediment, and fish monitoring; computer modeling; evaluation of policy options; and communication of findings to the scientific, industry and policy‐maker communities as well as the public. The RMP has allocated matching funds of $75,000 and in‐kind support for this project. Bay Area stormwater and wastewater agencies are also providing in‐kind support through access to sampling areas and expertise. This document outlines the environmental monitoring that will be conducted to address the data gaps that have been identified for San Francisco Bay and the sanctuaries. The document briefly explains the overall management questions that guide the long‐term monitoring for microplastic and provides a context for the goals for this specific project. The document articulates the specific hypotheses and research questions that guided the design of this sampling plan. Additional information on the overarching goals of the microplastic program can be found in the RMP Microplastic Strategy (Sutton and Sedlak 2017).