Determinación del potencial de acumulación de microplásticos en el tracto digestivo en la especie Oncorhynchus mykiss, mediante bioensayos de toxicidad.

Abstract

The objective of this research was to determine the potential for accumulation of microplastics in the digestive tract in the species Oncorhynchus mykiss, by means of toxicity bioassays. It began with the experimental design, which included 3 test groups, to be exposed to different concentrations and particle size of microplastic (PM), 5% - 1.5 mm, 10% - 3 mm and 20% - 1.5 + 3 mm, with their respective replica and a control group, each one with 10 trout, adult females, of 200 g in average weight. Subsequently, 7 swimming pools were designed and built, with a continuous flow of water from a natural source; The organisms were acclimated for 2 weeks, and then exposed 2 times a day to food contaminated with PM, for a period of 28 days. Finally, the organisms were sacrificed, determining the final average length and weight. Then the intestinal tract was extracted, to digest it and determine the content of MP. The results were statistically analyzed, it was obtained that there was accumulation of MP in the 3 groups studied, being higher the lower the concentration. Thus, for 10% and 5%, bioaccumulation reached 54% and 40% of MP, respectively. The length-weight relationship, demonstrated, effects on the growth of individuals, with a greater affection for 20% and 10% of MP, where, r2 = 0.11 and 0.37, respectively values far from the control group ( r2 = 0.72). Demonstrating that the concentration of the pollutant and its size can play a crucial role in the accumulation rates.