Plankton accumulate but are resistant to silver nanoparticles
Silver nanoparticles (AgNPs) are used in many consumer products, including bed sheets and washing machines, because of their antimicrobial properties; AgNPs are also making their way into aquatic environments. This is concerning for communities of microorganisms that may be sensitive to this emerging contaminant.
Our study found lake-dwelling freshwater plankton exposed to AgNPs, chronically or in pulses, accumulated silver but the patterns of accumulation suggest limits to the movement of AgNPs throughout the food web.
Read this open access paper on the FACETS website.
What we know about the effects of AgNPs is from short-term, laboratory studies that expose laboratory-grown communities in pulses.
We found complex, non-linear biological responses to AgNPs when studying a naturally occurring community of microbes, phytoplankton, and zooplankton that was exposed long-term (six weeks) to AgNPs in the IISD Experimental Lakes Area in Ontario, Canada.
Changes to size and abundance of plankton depended on the exposure type (chronic or pulsed). How much carbon (or energy) the ecosystem consumed — known as ecosystem metabolism — was not affected by exposure to AgNPs.
Our work shows that the way in which animals are exposed to AgNPs affects how they respond (e.g., exposure to low concentrations of AgNPs for a long time versus high concentrations of AgNPs for a short time). Simple approaches to predicting the toxicity and fate of this contaminant are complicated by the mismatch between community- and ecosystem-level responses to AgNPs.
Read the full paper — Muted responses to Ag accumulation by plankton to chronic and pulse exposure to silver nanoparticles in a boreal lake by Beth C. Norman, Paul C. Frost, Graham C. Blakelock, Scott N. Higgins, Md Ehsanul Hoque, Jennifer L. Vincent, Katarina Cetinic and Marguerite A. Xenopoulos.
