Microplastic pollution in marine environments has recently seen an increase in scientificattention, in part due to its slow natural degradation, but also due to it causing a wide range of ecological impacts. A lesser-known source of microplastic pollution are the antifouling systems used on shipping vessels. Antifouling paints are designed to prevent the growth of biofouling on marine surfaces and ship hulls. These paints can release antifouling particles (APP) into the environment through wear and tear or maintenance. Estimates of the emissions of microplastics from antifouling and the maritime industry are inconsistent and varied, due to the lack of standardized methodology and definitionsin the field. This study explores how previous research has quantified microplastics pollution from marine sources, with focus on methods used, analysis, reported results, and identifying methodological limitations. Using chronological, thematic, and methodological analysis, literature across several scientific databases was collected, reviewed, and analyzed for patterns and inconsistencies. The results show that the popularity of microplastics research has overshadowed antifouling research in recent times, passing it in terms of published studies in 2020. The thematic analysis shows that a lot of the research focuses on the occurrence of microplastics in the environment and its ecological effects, with less studies focusing on regulation and history. The methodological analysis reveals large variation in methods for definition, sampling, analysis, and the following results. The results show the differences in measured concentrations of microplastics, from none to extremely high, varying bylocation and method used. These observations illustrate the need for standardized methods and definition, and a lack thereof. The inconsistencies in the results and methods used impede the ability to compare studies and reliably assess the emission of harmful microplastics from marine environments and antifouling.