Microplastics have gained attention in recent times due to their dispersal across marine and coastal environments worldwide. Such widespread distribution exposes a broad range of organisms across the food chain, and presents a complex risk to individuals, populations and communities. Despite an increasing body of research into microplastics in the marine environment, our understanding of plastic pollution at the population and community scale is still limited. Very few studies have explored impacts on survival, growth and behaviour of organisms that ingest microplastics. Furthermore, our understanding surrounding the trophic transfer of associated microplastic contaminants and the resultant effects on the food web remain largely unknown. My research assesses the impacts of microplastics on the ecology of marine biota and the potential for trophic transfer using sandy coastal ecosystems as a model system. I am examining the impacts of microplastics on survival and key behaviours of beachhoppers, primary consumers that live in and around sediment. Moreover, I am evaluating the impact of trophic transfer of microplastics by feeding contaminated beachhoppers to sand gobies, ray finned fish that are natural predators. I will then assess any effects of microplastics on goby behaviour, specifically examining changes in the shyness-boldness continuum and spatial learning. We expect that microplastics and associated contaminants will accumulate in both beachhoppers and gobies, and subsequently modify the behaviour of these coastal biota. Understanding biological effects and the potential for microplastic pollutants to transfer through the food web has implications not only for the marine ecosystem, but also for human health and well being.