Abstract
In 2001, 150 tons of tannery waste was incorporated in the soil as a source of organic matter on the Monte Alegre Farm. This waste, which originates from the tannery industry and contains high chromium concentrations, was irregularly used as a soil fertilizer by farmers to produce mangoes, sugarcane, coffee, oranges, corn and lemons, contaminating the soils. This irregular application of tannery waste also contaminated stream sediment and bioaccumulated in some aquatic macroinvertebrate. The present study aims to collect current information about the aquatic macroinvertebrate community to make a comparison between chromium contamination in the Monte Alegre stream sediment with a study carried out in 2007 in the same place. The aquatic macroinvertebrate community was collected from April to September 2017 using an Ekman-Birge grab at two sampling points: one point at the forested area (Upstream Point) and another near the place of the contaminated soil (Downstream Point). Sediment samples were collected to analyze chromium concentration. The current concentration of chromium in the downstream point (impacted area) was higher than that obtained in 2007. The community metrics confirm that the taxonomic structure and diversity of the aquatic macroinvertebrate community to the Monte Alegre stream were affected by chromium. The results suggest that the environmental impact was maintained after ten years.
Keywords:
tannery waste; community indexes; contamination; aquatic invertebrates; metal
HIGHLIGHTS
• We evaluated the influence of chromium contamination on water quality in ten years.
• Aquatic macroinvertebrate community structure was influenced by land use.
• The area impacted by chromium showed lower macroinvertebrate richness and diversity.
• There were better environmental conditions in 2007 when compared to 2017.
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