Dams inevitably result in species decline, losses on reservoir islands
Hydropower development is booming, with controversial projects unfolding across the Americas, Africa, Asia and Europe. Though often presented as a green renewable energy option, dams can cause a litany of negative impacts: disrupting the downstream flow of nutrients, interrupting aquatic migration routes and harming fisheries. They flood forests, destroy habitat and increase the release of greenhouse gases as vegetation decomposes. Dams also displace human communities — submerging homes and indigenous territories. A new study adds another impact to the list, one that is widespread but has so far been overlooked by dam developers: “extinction debt” — the incremental but inexorable loss of species and diminishment of biodiversity over time on islands created by reservoirs. Hydropower developers have long claimed reservoir islands as quality habitat and as viable conservation areas — both assertions are false, according to the new research.
