ABSTRACT 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: To summarise what are microplastics; To discuss the routes by which microplastics enter the marine environment; To assess spatial and temporal trends of microplastic abundance; to discuss the environmental impact of microplastics; and remedial measures; 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. A case study has also been done about the ingestion of microplastics by zooplankton groups in Kenya’s marine environment. We conclude by highlighting key future research areas for scientists and policymakers. Keywords—Micro plastics; marine organisms; marine environment