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Made available in DSpace on 2019-10-06T16:17:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Climate change threatens freshwater fish by severely modifying water quality and hydrological dynamics, hence altering the species distribution. We assessed the climate change effects on the geographical distribution of Salminus brasiliensis, a keystone species of economic interest in the La Plata River basin. Using ecological niche models, we estimated the species range in the present time and assessed the range shift phenomena through climatically suitable areas in the future. We also quantified the predictive uncertainty from niche models, atmosphere–ocean general circulation models, and carbon emission scenarios. Our predictions indicated a great range contraction of S. brasiliensis in the future. The south-central portion of the basin should retain the climate refuge function for the species at 2050. Nonetheless, the segregation of this climate refuge in two smaller parts was predicted at the end of the century. Our study also revealed that the greatest source of uncertainty in forecasts of species range shifts arises from using alternative niche algorithms in modeling process. Our results contribute to more effective measures for conservation of S. brasiliensis, thus helping to ensure the ecosystem processes and socioeconomic activities in the basin dependent on this species. Programa de Pós-graduação em Ecologia de Ambientes Aquáticos Continentais. Núcleo de Pesquisas em Limnologia Ictiologia e Aquicultura - Nupelia Universidade Estadual de Maringá (UEM), Av. Colombo 5790 Programa de Pós-graduação em Ecologia – Universidade Federal de Juiz de Fora Instituto de Ciências Biológicas- ICB, Campus Universitário, Bairro São Pedro Departamento de Zoologia Instituto de Biociências de Rio Claro Universidade Estadual Júlio Mesquita Filho – UNESP Programa de Pós-Graduação em Ecologia e Evolução Universidade Federal de Goiás Universidade Estadual de Mato Grosso do Sul – UEMS Departamento de Zoologia Instituto de Biociências de Rio Claro Universidade Estadual Júlio Mesquita Filho – UNESP CNPq: 141371/2016-1

The use of multimetric indices (MMIs) became a common practice for evaluating ecological integrity of aquatic ecosystems. However, most developed MMIs ignore non-native species as an impact source to establish reference conditions. We developed an MMI to identify if non-native fish species are associated with Neotropical stream integrity by considering the presence of non-native species as an impact source. We calculated and evaluated responsiveness to the presence of non-native species using fish metrics, which were selected with a bootstrap procedure. Streams for calibration and validation were also selected with a bootstrap procedure. From the candidate MMIs generated, we selected models with different combinations of fish metrics. The generated MMIs presented a satisfactory performance in distinguishing reference streams from those impacted by non-native species. The abundance of non-native species was highly correlated with urbanization and seems to be more important than urbanization to drive native abundance loss. Our study is one of the first attempts to develop MMIs in which non-native species are considered as impact sources and used to identify impacted and reference sites. The final MMI that we developed might be a useful tool for aquatic biodiversity conservation and the development and application of non-native species control actions.