Online first articles

The Guiana Shield contains multiple freshwater ecosystems that support high species diversity. This ecoregion represents a stable landscape resulting from infrequent large-scale natural disturbances (i.e., Andean orogeny, marine incursions), favoring biological adaptations and endemisms (e.g., loricariids). However, disturbing human activities in nearby areas is a warning for the future of the Colombian Guiana Shield, and this requires assembling evidence that might contribute to the conservation of the region's biodiversity. We summarize information already available for the region and use field observations and laboratory studies to characterize the region's environmental variables and freshwater biodiversity. The Colombian part of the Guiana Shield is one of the best preserved because of low human density and reduced impacts. Although still relatively pristine, this region is already experiencing high growth in farming, contributing to forest loss. Other threats include infrastructure development, small-scale mining, livestock and water contamination. We developed a typology of river systems in the Colombian Guaina Shield that might be useful for conservation. There is ample evidence of the uniqueness of freshwater biodiversity and the threats affecting its conservation in the region. We present a conceptual relationship between the drivers, pressures and impacts currently existing in the Colombian Guiana Shield. Growing environmental impacts and future transformations require preserving these systems as a necessary step to expand our knowledge of their diversity and functions. To minimize current or future impacts requires involving local communities as well as the implementation of more strict policies, leading to a respectful development. Our recommendations could be useful for other areas in the Guiana Shield.