Blue-green algae in Rio Negro river (IMAGE) Université Laval Caption The scientists demonstrated this using data from 464 lakes in North and South America, including the Rio Negro river in Uruguay. Credit Luis Aubriot Usage Restrictions Only use with this news, give credit to Luis Aubriot. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.