Since the mass production of plastics began in the 1940s, microplastic contamination of the marine environment
has been a growing problem. Here, a review of the literature has been conducted with the following
objectives: (1) to summarise the properties, nomenclature and sources of microplastics; (2) to discuss
the routes by which microplastics enter the marine environment; (3) to evaluate the methods by which
microplastics are detected in the marine environment; (4) to assess spatial and temporal trends of microplastic
abundance; and (5) to discuss the environmental impact of microplastics. Microplastics are both
abundant and widespread within the marine environment, found in their highest concentrations along
coastlines and within mid-ocean gyres. Ingestion of microplastics has been demonstrated in a range of marine
organisms, a process which may facilitate the transfer of chemical additives or hydrophobic waterborne
pollutants to biota. We conclude by highlighting key future research areas for scientists and policymakers.