Dolphins in Fremantle inner Harbour (IMAGE) Edith Cowan University Caption Researchers are developing a new approach to monitor individual dolphin activity through matching unique sounds, known as signature whistles Credit Chandra Salgado Kent Usage Restrictions This image is only to be used accompanying this story with appropriate caption and credit. 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.