Effects of pollution: diversity and N-15 stable isotope content in macroinvertebrate functional groups of the Maipo river basin
Date:
María Paz Briones Alburquenque, Jorge Cortes Miranda, Caren Vega-Retter
Environmental pollution is considered one of the main disturbances threatening freshwater ecosystems, causing deterioration of water quality and phenomena such as eutrophication. Within these ecosystems, macroinvertebrates play a fundamental role, as they are a key group for organic matter recycling and for energy flow from primary producers to organisms of higher trophic levels such as fish. Macroinvertebrates can be classified into functional groups (FG) that differ according to feeding type: scrapers, shredders, filter feeders, collectors and predators. However, there is little evidence of the effects of pollution on these. The stable nitrogen isotope (15N) allows knowing the trophic level of organisms and the measurement of its proportion can identify the effects of diverse nitrogen sources in aquatic ecosystems. Therefore, this work proposes to determine the effect of pollution on diversity, 15N content and trophic position of macroinvertebrate functional groups in the Maipo River basin, given that it is considered one of the most disturbed in the country due to its high level of anthropic intervention. The results indicate that there is no variation in the diversity of functional groups between contaminated and uncontaminated sites, but a differentiation between macroinvertebrate families is observed. However, it was obtained that there is an increase in the isotopic content of the FGs in the contaminated sites, and in turn, their trophic position decreases. This suggests that pollution is causing an effect on food webs, modifying their structure and functioning.
Keywords: Pollution, Stable Isotopes, Macroinvertebrates, Functional Groups Financing: PAIFAC 2019 Funds