Largest known population of manta rays (IMAGE) Oregon State University Caption The largest known population of oceanic manta rays aggregates around Isla de la Plata off the coast of Ecuador. Credit Oliver Day, Oregon State University Usage Restrictions none 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.