Despite being hailed as conservation sanctuaries that protect species from hunting and deforestation, reservoir islands created by large dams across the world causing species loss every year, new research has found.
"We found a devastating reduction in species over time in the majority of reservoir islands we studied. On average, islands have 35 per cent fewer species than nearby mainland sites," said lead study author Isabel Jones from University of Stirling in Scotland.
"No matter where the dam is located, the island size, or which species are present, a sustained loss of species was found and potentially facing extinction," Jones noted.
Conservation experts examined research covering changes in species richness of birds, mammals, amphibians, reptiles, invertebrates and plants on more than 200 islands created by large dams.
Loss of species was investigated over a period of less than one year to over 90 years from when islands were created by reservoir filling.
With more than 50,000 large dams operating globally, including in highly biodiverse regions such as the Amazon basin, and many future dams planned to help meet rising energy demands, the researchers believe more needs to be done to account for the long-term loss of species on reservoir islands