Twenty four bottlenose dolphins, almost all juveniles, have died in Adelaide’s Gulf St Vincent in the past six weeks. At the same time, thousands of inshore reef fish have washed up on local beaches. The reason for these deaths remains unknown with initial analysis of some of the dead dolphins unable to determine their cause of death. Laboratory tests of tissue samples will not be completed for another two weeks.
Local waters are up to five degrees centigrade above normal for this time of the year. At this stage the most widely accepted theory for the deaths is a toxic build up of plant-like organisms called phytoplankton, often called a ‘red tide’. Although no such tide has been observed to date, it would be the first time such a toxic build up has affected dolphins in this part of the world.