"Study finds a little more than one-third of the longest rivers on the planet remain unobstructed by human-made changes "

"Only 37 percent of the world's longest rivers remain unimpeded and free-flowing from their source to where they empty, according to a study published today in Nature.

Free-flowing rivers are ecologically crucial — replenishing groundwater, bolstering biodiversity, and reducing the impacts of droughts and floods.

The study is the first to pinpoint the remaining free-flowing rivers on the planet and suggests economic development via dams, reservoirs, roads and hydropower is leading to decreased connectivity via rivers, which can harm freshwater species and reduce rivers' ability to mitigate floods and drought impacts.

'Rivers are the lifeblood of our planet,' said Michele Thieme, lead freshwater scientist at World Wildlife Fund and coauthor of the study, in a statement. 'They provide diverse benefits that are often overlooked and undervalued.'"

Brian Bienkowski reports for Environmental Health News May 8, 2019. [2]