Determinar a previsibilidade da carga de microplásticos em peixes e macroinvertebrados em riachos de uma bacia agrícola do neotrópico

Abstract

Despite the ubiquity of microplastics (MP), studies involving the ingestion of these particles by freshwater biota are rare in Neotropical regions, especially in those river environments that are surrounded by an agricultural matrix. In the present study, we tested the hypothesis that MP can be found in streams with agricultural surroundings and that the MP loads present in aquatic organisms are predictable according to their position in the stream, taxonomic characteristics, ecological characteristics and their body length. For this purpose, macroinvertebrates and fish were collected at 18 sampling points in six streams, which included collections in the upper, middle and lower reaches of each stream in the Comandaí basin (Brazil). Collections were carried out in the winter and spring seasons of 2022. For microplastic analysis processing, we selected organisms from different taxa of macroinvertebrates and fish and with different ecological characteristics. The fish were also measured to relate body size to MP load. A total of 106 plastic particles were recovered in macroivertebrates and 172 in fish, all sampled sites had organisms with the presence of MP. Blue/green and polyethylene fibers were the most abundant. Parameters such as trophic guild, position in the water column, stream section and average organism size were not significantly related to MP loads. The loads were uniform among the different taxa of fish and macroinvertebrates, which highlights the susceptibility of all organisms to plastic pollution.