San San River (IMAGE) Smithsonian Tropical Research Institute Caption In the Bocas del Toro region of Panama, manatees occur in turbid brackish waters, so visual counting methods are ineffective for calculating their population sizes. Credit Sean Mattson/STRI Usage Restrictions None License Licensed 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.