Manatee 2 (IMAGE) Smithsonian Tropical Research Institute Caption Health authorities believed manatees could help control the proliferation of water hyacinth in Gatun Lake, which were potential breeding grounds for disease-transmitting mosquitoes. Credit Unidad de Memoria Histórica del Canal de Panamá Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND 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.