Reducing adverse impacts of Amazon hydropower expansion

Abstract

Proposed hydropower dams at more than 350 sites throughout the Amazon require strategic evaluation of trade-offs between the numerous ecosystem services provided by Earth’s largest and most biodiverse river basin. These services are spatially variable, hence collective impacts of newly built dams depend strongly on their configuration. We use multiobjective optimization to identify portfolios of sites that simultaneously minimize impacts on river flow, river connectivity, sediment transport, fish diversity, and greenhouse gas emissions while achieving energy production goals. We find that uncoordinated, dam-by-dam hydropower expansion has resulted in forgone ecosystem service benefits. Minimizing further damage from hydropower development requires considering diverse environmental impacts across the entire basin, as well as cooperation among Amazonian nations. Our findings offer a transferable model for the evaluation of hydropower expansion in transboundary basins.

Poor downstream passage at a dam creates an ecological trap for migratory fish

“…Better solutions for downstream passage for a wide array of species are needed (Pelicice and Agostinho 2008). As dams continue to be built and operated worldwide (Flecker et al 2022;Zar et al 2015), and sh populations continue to decline (Hall et al 2012), solutions for downstream passage cannot come soon enough. For personal use only.…”

Biodiversity underpins fisheries resilience to exploitation in the Amazon river basin

“…Inland capture fisheries play critical roles in food security and livelihoods across the world, particularly in the largest tropical river basins, such as the Amazon [1]. Thus, a boom in tropical hydropower development, together with climate change, has received considerable attention for their potential impact on fisheries [2,3]. Overexploitation, however, remains pervasive albeit rarely quantified, particularly because the lack of high-quality data offers few opportunities for traditional approaches (e.g.…”

How Does Flow Alteration Propagate Across a Large, Highly Regulated Basin? Dam Attributes, Network Context, and Implications for Biodiversity

“…Leveraging network context‐dependencies, instead of ignoring them, could be an important step toward informing river ecosystem restoration via dam operation. This shift could also be important for prioritizing dam decommissioning (Guetz et al., 2021), or for mitigating socio‐environmental impacts in global regions where dam construction is underway (Flecker et al., 2022; Holtgrieve & Arias, 2022).…”