Influência Do Habitat No Impacto Das Espécies Exóticas Sobre A Ictiofauna Nativa Em Um Conjunto De Lagos Do Baixo Rio Doce, Espírito Santo, Sudeste Do Brasil

• Autor(a) principal: Barros, Eduardo Hoffmam de
• Data de Publicação: 2024
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/17449
• topic: Área(s) do conhecimento do documento (Tabela CNPq); Peixes; córregos; lagoas; espécies invasoras; subject.br-rjbn

The Doce River basin is the largest in southeastern Brazil, and over the last century, the Doce River has been undergoing a serious process of degradation, including a major environmental disaster. The Doce River in the coastal lowland harbors an extensive lake area, with over ninety lakes. These lakes are of fluvial origin and connected to each other and to the Doce River by small tributary streams. One of the main sources of impact on the ichthyofauna in the region is the presence of exotic fish species. We compared richness, taxonomic diversity, beta diversity, species composition and proportion of exotic species in lakes and streams, and related these variables to each other and to environmental variables. We used the indicator species index (IndVal) to identify species associated with each type of environment. We used multivariate analyses to test the influence of stream habitat on the fish fauna in streams. The results showed that some exotic species originating from lentic environments have adapted to the lakes and are spread throughout the internal lakes system. In streams, there are proportionally fewer exotic fish and their distribution is more fragmented, as some stretches do not provide the conditions for the establishment of some of these species, making them potential refuges for native ichthyofauna. As the streams move away from the lakes, the proportion of exotic species tends to decrease. In streams, the richness and diversity of native species are affected by the proportion of exotic species, but not in lakes. The native vegetation in the landscape showed not potential for reducing the invasion of exotics. The depth and width of the streams are directly related to the proportion of exotic species within the streams and are structural characteristics that should be considered in strategies for the conservation of the ichthyofauna. This thesis is divided into three chapters. The first presents a survey of species in the Doce River and internal lakes. The second chapter focuses on the central theme of the thesis, which is the evaluation of the influence of habitat on the impact of exotic fish species on native species. The third chapter presents some considerations on fish conservation in the region and how the information generated in this thesis can contribute to this topic.