Restricted-Range Fishes and the Conservation of Brazilian Freshwaters

Background: Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce. Methodology/Principal Findings: Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29%) watersheds have lost more than 70% of their original vegetation cover, and only 141 (26%) show significant overlap with formally protected areas or indigenous lands. We detected 220 (40%) critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future. Conclusions/Significance: We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked drainage systems. Proper management (e. g. forestry code enforcement, landscape planning) and conservation (e. g. formal protection) of the 540 watersheds detected herein will be decisive in avoiding species extinction in the richest aquatic ecosystems on the planet.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Gordon and Betty Moore Foundatio

The importance of forest cover for fish richness and abundance on the Amazon floodplain

Flooded forest is one of the most important fish habitats in Neotropical rivers, and one that is increasingly subjected to negative impacts from logging, agriculture, and other human activities. The purpose of our study was to test quantitatively whether fish richness and abundance in Amazonian floodplain lakes are associated with the area of flooded forest. We sampled fish and several other variables in 35 Amazonian floodplain lakes during the high-water season. Our results highlighted that fish richness and abundance were directly related to flooded forest, inversely related to distance from the river, and influenced by dissolved oxygen concentration <1 mg l−1. The same result applied to fish richness and abundance landed by fisheries. Other variables such as depth and area of open water habitat were also related but the results were less consistent and apparently reliant on sampling methodology. Our results suggest that conservation of the flooded forest is critical for the maintenance of fish assemblages in the Amazon, and that removal of flooded forest will reduce fish richness, fish abundance, and fisheries yield. © 2014, Springer International Publishing Switzerland