"A potentially harmful algae bloom covered more than 700 square miles in the western basin of Lake Erie last week, turning the lake bright green and alarming residents and local officials.

Scientists say that algae blooms have been a growing problem for Lake Erie since the 2000s, mostly because of the extensive use of fertilizer on the region’s farmland.

The algae blooms contain cyanobacteria, which, under certain conditions, can produce toxins that contaminate drinking water and cause harm to the local ecosystem."

Jugal K. Patel and Yuliya Parshina-Kottas report for the New York Times October 3, 2017. [2]