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Filters: Author is Natasha Klasios  [Clear All Filters]
2021
Klasios, N.; De Frond, H.; Miller, E.; Sedlak, M.; Rochman, C. M. 2021. Microplastics and other anthropogenic particles are prevalent in mussels from San Francisco Bay, and show no correlation with PAHs. Environmental Pollution 271.

Microplastics are an emerging contaminant of high environmental concern due to their widespread distribution and availability to aquatic organisms. Filter-feeding organisms like bivalves have been identified as particularly susceptible to microplastics, and because of this, it has been suggested bivalves could be useful bioindicators of microplastic pollution in ecosystems. We sampled resident mussels and clams from five sites within San Francisco Bay for microplastics and other anthropogenic microparticles. Cages of depurated mussels (denoted transplants) were also deployed at four sites in the Bay for 90 days to investigate temporal uptake of microplastics and microparticles. Because microplastics can sorb PAHs, and thus may act as a source of these chemicals upon ingestion, transplant mussels and resident clams were also analyzed for PAHs. We found anthropogenic microparticles in all samples at all sites, some of which were identified as microplastics. There was no statistical difference between the mean number of microparticles found in resident and transplant species. There were significant site-specific differences among microparticle abundances in the Bay, with the highest abundances observed in the South Bay. No correlation was found between the number of microparticles and the sum concentrations of PAHs, priority PAHs, or any individual PAH, suggesting the chemical concentrations observed reflect broader chemical trends in the Bay rather than direct exposure through microplastic ingestion. The pattern of spatial distribution of microparticles in transplanted mussels matched that of sediment samples from the Bay, suggesting bivalves could be a useful bioindicator of microplastic abundances in sediment, but not surface water.

2020
Hung, C.; Klasios, N.; Zhu, X.; Sedlak, M.; Sutton, R. 2020. Methods Matter: Methods for Sampling Microplastic and Other Anthropogenic Particles and Their Implications for Monitoring and Ecological Risk Assessment. Integrated Environmental Assessment and Management 16 (6) . SFEI Contribution No. 1014.

To inform mitigation strategies and understand how microplastics affect wildlife, research is focused on understanding the sources, pathways, and occurrence of microplastics in the environment and in wildlife. Microplastics research entails counting and characterizing microplastics in nature, which is a labor‐intensive process, particularly given the range of particle sizes and morphologies present within this diverse class of contaminants. Thus, it is crucial to determine appropriate sampling methods that best capture the types and quantities of microplastics relevant to inform the questions and objectives at hand. It is also critical to follow protocols with strict quality assurance and quality control (QA/QC) measures so that results reflect accurate estimates of microplastic contamination. Here, we assess different sampling procedures and QA/QC strategies to inform best practices for future environmental monitoring and assessments of exposure. We compare microplastic abundance and characteristics in surface‐water samples collected using different methods (i.e., manta and bulk water) at the same sites, as well as duplicate samples for each method taken at the same site and approximate time. Samples were collected from 9 sampling sites within San Francisco Bay, California, USA, using 3 different sampling methods: 1) manta trawl (manta), 2) 1‐L grab (grab), and 3) 10‐L bulk water filtered in situ (pump). Bulk water sampling methods (both grab and pump) captured more microplastics within the smaller size range (<335 μm), most of which were fibers. Manta samples captured a greater diversity of morphologies but underestimated smaller‐sized particles. Inspection of pump samples revealed high numbers of particles from procedural contamination, stressing the need for robust QA/QC, including sampling and analyzing laboratory blanks, field blanks, and duplicates. Choosing the appropriate sampling method, combined with rigorous, standardized QA/QC practices, is essential for the future of microplastics research in marine and freshwater ecosystems.

Miller, E.; Klasios, N.; Lin, D.; Sedlak, M.; Sutton, R.; Rochman, C. 2020. Microparticles, Microplastics, and PAHs in Bivalves in San Francisco Bay. SFEI Contribution No. 976. San Francisco Estuary Institute: Richmond, CA.

California mussels (Mytilus californianus and hybrid Mytilus galloprovincialis / Mytilus trossulus) and Asian clams (Corbicula fluminea) were collected at multiple sites in San Francisco Bay. Mussels from a reference area with minimal urban influence were also deployed in cages for 90 days at multiple sites within the Bay prior to collection.Mussels from the reference time zero site, Bodega Head, had some of the lowest microparticle levels found in this study, along with resident clams from the San Joaquin and Sacramento Rivers and mussels transplanted to Pinole Point. The highest concentrations of microparticles were in mussels transplanted to Redwood Creek and Coyote Creek. The results of this study and current literature indicate that bivalves may not be good status and trends indicators of microplastic concentrations in the Bay unless the interest is in human health exposure via contaminated bivalve consumption.

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