How well-protected are protected areas from anthropogenic microplastic contamination? Review of analytical methods, current trends, and prospects

Microplastics have sparked global concern due to their negative effects on organisms' health and the environment. Microplastics research in protected areas (marine and freshwater) has recently gained prominence and is expected to grow in the coming years. This review of 36 published studies examines current progress and identifies future research challenges. It begins with an overview of microplastic evaluation methodologies, followed by a discussion of recent advances in the abundance of microplastics in water, sediment, biota, wet and dry deposition, and particulate matter. Current quality assurance and control measures are also summarized. The majority of studies (44 %) examined sediment samples. In biota, the gastrointestinal system was the most evaluated for microplastics. Digestion (using H2O2 and KOH) and density separation (using NaCl) are the most common microplastic extraction methods. We found that microplastic contamination is pervasive in all the surveyed protected areas, with varying levels of abundance geographically, and over 50 % of the biota ingest microplastics. The methodological discrepancies amongst the investigations, from sampling to microplastics characterization, make it difficult to compare the results and generate baseline data on microplastic contamination levels. Close monitoring and a standardized approach are thus required to determine the extent to which microplastics might enter and persist in protected area environments, as well as to devise effective mitigating strategies.

Automated summary

Microplastics have gained global attention for their negative impacts on organism health and the environment. Recent studies in protected areas have shown that microplastic contamination is widespread, with varying levels of abundance geographically and over 50% of biota ingesting microplastics. Methodological discrepancies pose challenges in comparing results and generating baseline data on microplastic contamination levels. Close monitoring and a standardized approach are necessary to assess the extent of microplastic entry and persistence in protected area environments.