ABSTRACT. The amount of plastic waste entering the global ocean and breaking down into microplastic particles continues to grow, with predictions that it will triple within the next thirty years without serious changes in societal use and management of plastic materials. This presentation provides an overview of our research into the environmental fate, biological uptake and ecotoxicology of micro- and nano- plastics in marine organisms and ecosystems. Our work uses detailed laboratory ecotoxicology work looking at how the surface properties and shape of macroplastic particles influence the biofouling and aggregation of particles, and their uptake and movement through organisms following ingestion, which can all influence the toxicity of microplastics to cells and tissues. We have then applied traits-based analysis to look at how organismal traits and feeding ecology influence the exposure and uptake of microplastics in benthic marine species. Finally, I will talk about the work we have been doing in the Galapagos Islands, where despite the high levels of environmental protection provided by the Galapagos National Park, high levels of plastic and microplastic waste are now accumulating. Yet the unique geographical setting and protection of the Galapagos Islands provide an opportunity to map the flows and impacts of plastic contamination on an island ecosystem scale, and test innovative solutions to this growing societal problem.