Vulnerability of Amazonian Fishes to Climate Change

Mounting scientific evidence suggests that human-induced climate change in the Amazon region will result in substantial alterations to the precipitation regimes. These changes will subsequently alter river hydrology, decrease dissolved oxygen, influence primary productivity, and compromise habitat quality and other critical resources for freshwater fishes. Currently, 71 species of freshwater fish are threatened in the Brazilian Amazon owing to a variety of present-day threats that include river regulation and fragmentation by dams and habitat loss, yet surprisingly there is little information about the vulnerability of these species to future threats associated with on-going climate change. Here, we report on the results of an expert survey that sought to uncover the potential vulnerability of threatened Amazonian fishes to changes in water quantity and quality associated with climatic change. We developed a multi-metric index to score opinions of experts regarding climatic change vulnerabilities of each threatened species. We found that Amazonian fishes exhibited a range of expected vulnerabilities to climate change, and that a number of critical knowledge gaps since exist that allow for a comprehensive evaluation. Our study advances the understanding of climate change impacts on tropical freshwater biota.