A large-scale assessment of anthropogenic threats to aquatic biodiversity across the Amazon

Abstract

Deforestation and forest degradation are resulting in pervasive changes to tropical ecosystems around the globe. While evidence from terrestrial systems demonstrate the severity of these disturbances for biodiversity conservation and provision of ecosystem services, the consequences for freshwater ecosystems remain poorly understood. This is especially true for the Amazon basin, the world´s largest in area and total discharge, and in particular for the complex network of low-order streams that make up the vast majority of its watercourses. These streams connect terrestrial and aquatic ecosystems throughout landscapes and host much, if not the majority, of the freshwater fish fauna of the Amazon basin, which itself is one of the most diverse in the world. Conservation planning for the Amazon, which is characterized by daunting knowledge gaps, is challenging. Management and conservation strategies are mainly based on criteria developed for terrestrial biota and unlikely to efficiently safeguard the freshwater ecosystems. In this project we will address part of this knowledge gap by investigating if areas more relevant to the conservation of aquatic and terrestrial biodiversity overlap and how threats to freshwater biodiversity are distributed and layered across the Amazon. We will use field data on biodiversity already collected in Santarém and Paragominas, PA, as well as obtain a wide set of indicators of human pressures from satellite imagery for the whole Brazilian Amazon (e.g. deforestation, fire hotspots, small dams etc), which can directly and indirectly affect freshwater systems. We will use our findings to suggest priorities for the management and conservation of stream systems in the Brazilian Amazon, and human modified tropical forest landscapes in general.