Author(s): Anita Laborde; Oscar Link; Pedro Arriagada; Evelyn Habit
Linked Author(s): Oscar Link
Keywords: No Keywords
Abstract: Hydropower as a clean and mature technology is experiencing a development boom worldwide, but at the same time associated longitudinal fragmentation of the physical habitat worsen the conservation status of freshwater species, challenging sustainability, especially due to synergic effects of several projects in the species distribution area. What and how hydroelectric projects will affect species, depend on a number of attributes such as power plants location and size, as well as species biological and ecological characteristics, distribution, and conservation status. Mitigation technologies to reduce the impact of hydropower projects on freshwater fish species, such as behavioural barriers, translocation, technical and nature-like fishways are available, but their effectiveness depends on a case to case basis. We analyse Chilean freshwater species distributed over 10 major basins of Central Chile threaten by 1124 plants (totalizing an installed capacity of 12,338 GW) planned in a hotspot of biodiversity including the Chilean ichthyogeographic province. The analysis consider species distribution, conservation status, and richness, as well as location, size, head and turbine type of hydropower projects. Results show that the projects located in reaches with information about species compile 45% of the exploitable potential, with 69.8% located in the Andean range, and 58.7% in reaches with low Strahler order (≤3). 75.5% have installed capacities less than 20 MW and 88.1% consider low head dams (< 20 m). 22.6% of the species are not exposed to planned plants, 54.8% are exposed to a small number of plants (< 5), and 22.6% are frequently exposed to plants (> 60). The latter species pertain to genera Trichomycterus, Percilia, and Diplomystes, defining a critical fish assemblage that facilitates the management of an important part of the cases (40.4%) through mitigation technologies.