Influência de fatores ambientais locais e regionais sobre a abundância de guildas reprodutivas e tróficas de peixes em reservatórios do Estado do Paraná.
Freshwater ecosystems are among the most threatened in the Planet. Construction and operation of dams are the main factors altering fluvial dynamics, negatively affecting the integrity of aquatic biota. For instance, in South Brazil there are more than 146 large reservoirs. Most of the main rivers and their tributaries, in this region, are completed fragmented by series of dams. Besides the high number of reservoirs, little attention was given to identify the environmental factors that shape ichthyofauna structure in these ecosystems. This knowledge is fundamental in the evaluation of species behavior resulted from the impacts prompted by reservoirs. In this study, reproductive and trophic guilds were used to analyze the hypothesis that there is a relationship between local (limnological variables) and regional (geographic position of a reservoir) environmental factors, with the structure of fish assemblages in 30 reservoirs located in the Paraná State, Brazil. To achieve proposed objective, indirect (correspondence analysis - CA) and direct (Canonical Correspondence Analysis - CCA, and partial CCA) gradient analysis were used. In addition, the relative contributions of local and regional environmental variables, as well as their interaction, on the explanation of the variation in the CPUE of guilds, were evaluated (using inertia partitioning). CPUEs of guilds were related to local and regional environmental factors. However, local factor were not significant when the effect of the variation of the regional factors were controlled. This indicates a hierarchical dependence among the spatial scales of the environmental variables. Yet, the relationship between guilds (reproductive and trophic) abundance were strongly influenced by theirs own distribution in each sub-basin, mainly due to geographic isolation (natural and artificial), in addition to the spatial sampling restriction of the study (only the lacustrine zone of reservoirs was sampled).
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| Format: | Thesis/Dissertation biblioteca |
| Language: | Portuguese |
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Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
2008
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| Subjects: | Freshwater fishes, Ciências Ambientais, Guild, Fish, Large-scale, Paraná State, Reservoirs, Brazil, Reservatórios, Ampla escala, Estratégias reprodutivas e tróficas, Fatores ambientais abióticos, Peixes de água doce, Gradiente ambiental, Guilda, Brasil, Paraná (Estado), Environment gradient, |
| Online Access: | http://hdl.handle.net/1834/10018 |
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