First approach to microplastics occurrence in sandy beaches in the province of Islay (Arequipa), southern Peru

Plastic pollution in marine and coastal environments has been widely recognized as a growing environmental concern. Plastic particles generated mainly by the degradation of larger plastic debris have been called microplastics (< 5 mm), which are being widely studied in all regions of the world. In South America there has been a constant increase of the research on this topic mainly on the Pacific coast. Specifically, in Peru, the number of publications has also increased, but the northern and southern zones are not well studied. Due to the importance of determining the presence of these contaminants, especially in coastal regions, which are considered as repository environments for these plastics, it is necessary to establish baselines of their current situation. This research aimed to determine and characterize the presence of microplastic particles (< 5 mm) on five sandy beaches in the province of Islay in southern Peru and to consider the possible effect of the Tambo River mouth on the transport and deposition of microplastics on two adjacent beaches. Three sampling stations were determined for each selected beach, consisting of three to two quadrants (1 m2) sampled at 5 cm depth. The results confirm the presence of microplastics. A total of 304 particles were found, with an average density between 1 to 4 part/m2. The areas with the highest concentration of microplastic particles and frequency of occurrence were the beaches adjacent to the river estuary where the most frequent types of particles were fragments and fibers, followed by foams and films, but no pellets.