Distribution and abundance of Chironomidae (Diptera, Insecta) in an impacted watershed in South-east Brazil

Abstract

Patterns of abundance and distribution of chironomid midges (Diptera, Chironomidae) in the middle Rio Doce basin were analysed. Human activities (mining, steel processing, and Eucalyptus spp. forestry) contribute to environmental degradation and low water quality in this watershed. Physical and chemical water traits (dissolved oxygen, pH, total alkalinity, electric conductivity, phosphorus and nitrogen concentrations) of 20 sampling points were used in a Principal Component Analysis (PCA) to establish the best and worst water quality. Sampling points recorded as the most polluted showed low genus richness of Chironomidae, less than five genera from the total 23, and dominance of the genus Chironomus, a bioindicator of environmental stress. Following Chironomus, the second most frequent and abundant genus was Cricotopus, whose distribution could not be related to pollution levels. The Tanypodinae sub-family showed certain sensitivity to low dissolved oxygen concentrations and high nutrients levels, and was not found at points of high pollution levels.

Habitats and trophic relationships of Chironomidae insect larvae from the Sepotuba River basin, Pantanal of Mato Grosso, Brazil

“…According to Trivinho- Strixino and Strixino (1991), organic matter is one of the major food sources in lakes and reservoirs that contribute to the balance of the systems in terms of diversity and richness of faunistic groups. Marques et al (1999) confirmed that in genera of Tanypodinae the distribution is limited by the presence of vegetation fragments and algae, by the type of sediment, or by the concentration of nutrients. A. gr.…”

“…C. strenzkei in the sampling sites in lakes may indicate an environment with characteristic water quality of high oxygen saturation, low productivity and low eutrophication Marques et al, 1999). Some species of Chironomus prefer or are restricted to water bodies with humic and fulvic substances.…”

Macroinvertebrates in low-order streams in two fragments of Atlantic Forest in different states of conservation, in the State of São Paulo (Brazil)

“…According to Marques et al (1999), this family can be considered common and tolerant to a wide array of environmental conditions. The number of chironomid species inhabiting any freshwater body is normally far superior to that of any other taxonomic group (Int Panis, 1995).…”

Efeito da contaminação de cromo em macroinvertebrados aquáticos no córrego Monte Alegre: estrutura da comunidade e teste de toxicidade

“…Para o teste crônico, o sedimento mostrou-se com indício de toxicidade no ponto 1 e 3, e tóxico no ponto 2 (Tabela 13). (RODRIGUES, 2003;PAULA, 2008;POSSETTI, 2015;MELLO, 2015;KUZMANOVIĆ et al, 2016;CHIRWA e CHILIMA, 2017;ZHANG et al, 2018 O gênero Chironomus é muito tolerante à poluição orgânica e a condições de eutrofização, sendo considerado um indicador de perturbação ambiental (Marques et al, 1999). Peláez-Rodriguez (2001) ainda afirma que em ambientes altamente impactados são os únicos representantes da família Chironomidae.…”