Just as the “biosphere” is the thin layer of life on the outside of our planet Earth, we coined the term “Plastisphere” to refer to the thin layer of diverse metazoan and microbial life that develops on any piece of plastic in aquatic environments. The problems of entanglement and ingestion by fish, turtles, birds, and marine mammals are well recognized, but the microbial community on this manufactured substrate is just beginning to be studied. Global plastic production exceeds 300 million tonnes per year and it is estimated that up to 5% of this is entering the ocean as plastic litter. As a result, plastic is now the most common form of debris in the ocean, reaching concentrations of over 1 million pieces per square kilometer in ocean accumulation zones. Each of these pieces develops a microbial biofilm that may contribute to global nutrient cycling, toxin transport, trophic web interactions, plastic degradation, and the spread of potential pathogens. Using a combination of imaging, culture work, next-generation amplicon sequencing, and metagenomics on both field and experimental samples we are investigating the diversity and function of the Plastisphere community in collaboration with Tracy Mincer at Woods Hole Oceanographic Institution and Erik Zettler at SEA Education Association.
There is substantial public and scientific interest in plastic in the ocean and this work has been covered by newspapers, magazines, on-line blogs, webinars, children’s books, and even an art exhibition in Berlin! It is good that people are aware of and responding to an environmental problem…unfortunately much of the information in the media is not accurate. Most people have heard of the ‘Great Pacific Garbage Patch’, and many people have an image of vast swirling “islands” of plastic in the middle of the ocean, but this is incorrect. There is a lot of plastic in the ocean but most of it in the open ocean is in the form of dispersed small fragments smaller than your fingernail. In even the most polluted areas of the open ocean you would usually not notice the plastic unless you used a net to concentrate it. Our goals are to provide accurate information about the impact of plastic in the ocean by understand the microbial community that develops on it and how these microbes impact the plastic itself, as well as the surrounding ecosystem. Resources to address environmental problems are limited, so it is important that we understand the problem so that policy makers can make good decisions.
Photo Credits: SEA
Plastisphere Publications (to see full list of Amaral Zettler publications, click here)
2015 Amaral-Zettler* L.A., Zettler, E.R., Slikas, B., Boyd, G.D., Melvin, D.W., Morrall, C.E., Proskurowski, G., Mincer, T.J. 2015. Biogeography of the Plastisphere: Implications for Policy. Frontiers in Ecology and the Environment. 13(10): 541–546. doi:10.1890/150017.
2015 Mincer, T.J., Zettler, E.R., Amaral-Zettler, L.A. Biofilms on plastic debris and their influence on marine nutrient cycling, productivity, and hazardous chemical mobility, in Hazardous Chemicals Associated with Plastics in the Environment (edited by Hideshige Takada and Hrissi Karapanagioti). Springer. In Press.
2014 V. Schmidt, V.T., J. Reveillaud, E. Zettler, T.J. Mincer, L. Murphy and L.A. Amaral-Zettler Oligotyping reveals community level habitat selection within the genus Vibrio. Front. Microbiol., DOI: 10.3389/fmicb.2014.00563
2013 Zettler, E.R., T.J. Mincer, and L.A. Amaral-Zettler. Life in the “Plastisphere”: Microbial communities on plastic marine debris. Env.Sci.&Tech.: DOI: 10.1021/es401288x