2017 Margins Microplastics Cruise Report

San Francisco Estuary Institute (SFEI) | October 2nd, 2017

This report contains information on the summer field sampling efforts conducted by Coastal Conservation & Research (CC&R) in support of two Regional Monitoring Pr

This report contains information on the summer field sampling efforts conducted by Coastal Conservation & Research (CC&R) in support of two Regional Monitoring Program (RMP) studies: South Bay Margins and Moore Microplastics. The South Bay Margins is the second round of a larger San Francisco Bay study collecting sediment and water in shallow margin areas of the bay. The first round was conducted in Central Bay in 2015. The Moore Microplastics study is a collaborative effort with the Moore Foundation to collect sediment and fish samples in San Francisco and Tomales Bays. The work for both studies was contracted through the San Francisco Estuary Institute (SFEI) to CC&R. Since overall project management and sampling locations were coordinated between the two projects, activities from both studies will be presented as they occurred. 

Anthropogenic debris in seafood: Plastic debris and fibers from textiles in fish and bivalves sold for human consumption

Nature | September 24th, 2015

The ubiquity of anthropogenic debris in hundreds of species of wildlife and the toxicity of chemicals associated with it has begun to raise concerns regarding the presenc

The ubiquity of anthropogenic debris in hundreds of species of wildlife and the toxicity of chemicals associated with it has begun to raise concerns regarding the presence of anthropogenic debris in seafood. We assessed the presence of anthropogenic debris in fishes and shellfish on sale for human consumption. We sampled from markets in Makassar, Indonesia and from California, USA. All fish and shellfish were identified to species where possible. Anthropogenic debris was extracted from the digestive tracts of fish and whole shellfish using a 10% KOH solution and quantified under a dissecting microscope. In Indonesia, anthropogenic debris was found in 28% of individual fish and in 55% of all species. Similarly, in the USA, anthropogenic debris was found in 25% of individual fish and in 67% of all species. Anthropogenic debris was also found in 33% of individual shellfish sampled. All of the anthropogenic debris recovered from fish in Indonesia was plastic, whereas anthropogenic debris recovered from fish in the USA was primarily fibers. Variations in debris types likely reflect different sources and waste management strategies between countries. We report some of the first findings of plastic debris in fishes directly sold for human consumption raising concerns regarding human health.

Examination of the ocean as a source for atmospheric microplastics

PLoS ONE | May 12th, 2020

Global plastic litter pollution has been increasing alongside demand since plastic products gained commercial popularity in the 1930s. Current plastic pollutant research

Global plastic litter pollution has been increasing alongside demand since plastic products gained commercial popularity in the 1930s. Current plastic pollutant research has generally assumed that once plastics enter the ocean they are there to stay, retained permanently within the ocean currents, biota or sediment until eventual deposition on the sea floor or become washed up onto the beach. In contrast to this, we suggest it appears that some plastic particles could be leaving the sea and entering the atmosphere along with sea salt, bacteria, viruses and algae. This occurs via the process of bubble burst ejection and wave action, for example from strong wind or sea state turbulence. In this manuscript we review evidence from the existing literature which is relevant to this theory and follow this with a pilot study which analyses microplastics (MP) in sea spray. Here we show first evidence of MP particles, analysed by μRaman, in marine boundary layer air samples on the French Atlantic coast during both onshore (average of 2.9MP/m3) and offshore (average of 9.6MP/ m3) winds. Notably, during sampling, the convergence of sea breeze meant our samples were dominated by sea spray, increasing our capacity to sample MPs if they were released from the sea. Our results indicate a potential for MPs to be released from the marine environment into the atmosphere by sea-spray giving a globally extrapolated figure of 136,000 ton/yr blowing on shore.

Gut Contents Analysis of Four Fish Species Collected in the San Leandro Bay RMP PCB Study in August 2016

San Francisco Estuary Institute (SFEI) | November 7th, 2018

In support of PCB modeling for San Leandro Bay, a Priority Margin Unit (PMU) for PCB load reduction in the estuary, fish samples of four species (topsmelt, shiner perch,

In support of PCB modeling for San Leandro Bay, a Priority Margin Unit (PMU) for PCB load reduction in the estuary, fish samples of four species (topsmelt, shiner perch, white croaker, and northern anchovy ) were obtained in August 2016 for both tissue analysis and examination of gut contents. The bay was sampled at eight locations, with a repeated sampling at one location (Airport Lagoon) for one species (topsmelt). Fish were measured, weighed, and dissected, and their gut contents examined microscopically. Topsmelt (9 samples, 188 specimens) had the greatest variety of food items, with gammarid amphipods and chain diatoms predominating. Some topsmelt, especially larger individuals, consumed macroalgae as a major dietary component. Two samples at two sites for shiner perch (20 fish each) had contents composed of close to 50% gammarids at both sites, but differed in proportions of bivalves and polychaetes among the important food items. The one sample of white croaker had consumed mostly gammarids, with fish and polychaetes ranking next in importance. A single sample of northern anchovy (20 fish analyzed) differed radically from the other species in consuming mainly a diatom that appears to have been filtered from the water column. Trace amounts of plastic fiber were seen in all species except shiner perch. All exposure to sediment appeared to have occurred in the top 2 cm of the sediment column, or as contact with flocculent material on plants or hard substrates, or even in the water column, as some fine sand grains were seen in all fish, even anchovy. There was no conclusive evidence of site-specific foraging (site fidelity). The best spatial coverage was for topsmelt, and these fish appear to have fed opportunistically, with some evidence for having fed outside San Leandro Bay.

Microparticles, Microplastics, and PAHs in Bivalves in San Francisco Bay

San Francisco Estuary Institute (SFEI) | November 15th, 2019

Microplastic Contamination in San Francisco Bay - Fact Sheet

San Francisco Estuary Institute (SFEI) | November 2nd, 2015

Microplastic Monitoring and Science Strategy for San Francisco Bay

San Francisco Estuary Institute (SFEI) | February 1st, 2017

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducted a

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducted a special study to measure microplastic in treated wastewater effluent and Bay surface water. Bay surface water appeared to have higher microplastic levels than other urban water bodies sampled in North America, such as the Great Lakes and Chesapeake Bay. Microbeads derived from personal care products and tiny fibers, a portion of which were likely derived from synthetic clothing, were recovered from all nine Bay sites. Tiny particles, primarily fibers, were also detected in treated effluent from Bay Area facilities; not all of these particles are known to be plastic. These findings received considerable media attention and catalyzed state and federal policy shifts. 

Microplastic pollution is widely detected in US municipal wastewater treatment plant effluent

Environmental Pollution, Elsevier | August 27th, 2016

Municipal wastewater effluent has been proposed as one pathway for microplastics to enter the aquatic environment. Here we present a broad study of municipal wastewater t

Municipal wastewater effluent has been proposed as one pathway for microplastics to enter the aquatic environment. Here we present a broad study of municipal wastewater treatment plant effluent as a pathway for microplastic pollution to enter receiving waters. A total of 90 samples were analyzed from 17 different facilities across the United States. Averaging all facilities and sampling dates, 0.05 ± 0.024 microparticles were found per liter of effluent. Though a small value on a per liter basis, even minor municipal wastewater treatment facilities process millions of liters of wastewater each day, yielding daily discharges that ranged from ∼50,000 up to nearly 15 million particles. Averaging across the 17 facilities tested, our results indicate that wastewater treatment facilities are releasing over 4 million microparticles per facility per day. Fibers and fragments were found to be the most common type of particle within the effluent; however, some fibers may be derived from non-plastic sources. Considerable inter- and intra-facility variation in discharge concentrations, as well as the relative proportions of particle types, was observed. Statistical analysis suggested facilities serving larger populations discharged more particles. Results did not suggest tertiary filtration treatments were an effective means of reducing discharge. Assuming that fragments and pellets found in the effluent arise from the ‘microbeads’ found in many cosmetics and personal care products, it is estimated that between 3 and 23 billion (with an average of 13 billion) of these microplastic particles are being released into US waterways every day via municipal wastewater. This estimate can be used to evaluate the contribution of microbeads to microplastic pollution relative to other sources (e.g., plastic litter and debris) and pathways (e.g., stormwater) of discharge.

Microplastic Strategy Update on behalf of the Regional Monitoring Program (RMP) for Water Quality in San Francisco Bay

San Francisco Estuary Institute (SFEI) | December 2nd, 2019

Based on the detection of microplastics in San Francisco Bay surface water and Bay Area wastewater effluent in 2015, the Regional Monitoring Program for Water Quality in

Based on the detection of microplastics in San Francisco Bay surface water and Bay Area wastewater effluent in 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) convened a Microplastic Workgroup (MPWG) in 2016 to discuss the issue, identify management information needs and management questions (MQs), and prioritize studies to provide information to answer these management questions. The MPWG meets annually to review on-going microplastic projects and to conduct strategic long-term planning in response to new information in this rapidly evolving field.

Microplastics from Tire Particles in San Francisco Bay

San Francisco Estuary Institute (SFEI) | March 14th, 2022