by Mike Gaworecki on 8 May 2019
- Just one-third of the planet’s 242 longest rivers still flow uninterrupted along their entire length, most of them located in remote regions of the Arctic, the Amazon Basin, and the Congo Basin, according to a study to be published in Nature tomorrow.
- The international team of researchers behind the study, led by Günther Grill of Canada’s McGill University, determined that, of the 91 rivers longer than 1,000 kilometers (about 600 miles) that once emptied out into an ocean, only 21 are still unobstructed from their source to the sea.
- Dams and associated reservoirs are the biggest causes of river obstruction, the researchers say. There are nearly 60,000 large dams in the world already, and as many as 3,700 more large hydroelectric dams are currently in the planning stages or under construction.
- Healthy rivers provide a number of benefits to mankind, from recreation to food security. Ensuring the connectivity of the world’s remaining free-flowing rivers is also critical if we’re to preserve biodiversity in freshwater systems.