Distribution of microplastics in water and sediment matrices in the Colorado River, Patagonia, Argentina.

MORA GUILLERMO ALEJANDRO; MACCHI PABLO ANTONIO; ARIAS ANDRES HUGO

Concepción

Conferencia; Workshop "La contaminación por plásticos y su impacto en el medio ambiente y la salud humana? SPLACH Red de investigadores ? Chile - Scientific Plastic Pollution Alliance of Chile (SPLACH) network; 2022

Universidad San Sebastian

The Colorado River is one of the most important rivers in Patagonia Argentina. The various land uses in its watershed can contribute to plastic inputs. Therefore, the objective of this study was to identify and quantify the first records of PM loads in water and sediments of the Colorado River. For this purpose, 12 sites were selected along a longitudinal gradient (approximately 1000 km) and samples were collected by filtering 100 L of water (Mora, et. al. 2022); in addition, an integrated sample of 3 sediment replicates was collected from one of the river banks using a stainless steel corer along a 50- 100 m transect. The average concentration of MPs in sediment was 160 ±137.51 MPs.kg-1 dry weight. The maximum concentration found (205 MPs.Kg-1 dry weight) was in the upper sector. The most frequent forms of MPs were fibers (91.66%), predominantly blue (47.92%) and black (21.88%). Comparatively between the records of both matrices, the results indicate a high level of incidence of plastic contamination of the freshwater ecosystem comparable to other studies in rivers around the world. This preliminary study quantifies for the first time the concentrations of PMs in the Colorado River in sediment and water matrices, describing their distribution and the contribution of the basin to the Atlantic Ocean, as well as their possible impacts on the environment.