UC Santa Cruz

Freshwater ecosystems cover less than 0.01% of Earth's surface but are home to nearly one-quarter of all vertebrate diversity. Much of this diversity is concentrated in large tropical rivers, including the Amazon (961 species), Mekong (309 species), Congo (375 species), and the Ogooué River in Gabon (351 species), but these large rivers are threatened by proposed dam development. Globally, freshwater ecosystems are highly threatened and 36% of freshwater fishes are considered endangered, but efforts to protect freshwaters are poorly developed.

With over 400 species of fresh and brackish water fishes, Gabon, represents a freshwater biodiversity hotspot. But Gabon’s freshwater species are threatened by proposed dam development including a total of 38 potential hydropower dam sites across the country, and 28 in the Ogooué watershed. We know comparatively little about the biodiversity and biogeography in Gabon’s freshwater ecosystems, so I have used a combination of field work, taxonomy, and modeling to determine the distribution of freshwater biodiversity in Gabon. We developed a novel application of MaxEnt Modelling and a new metric, species pseudorichness index, to assess the impacts of proposed dam development and provide clear guidance for freshwater conservation in Gabon.