The Whale Protection Institute reported an increase in the number of whales found dead in southern Argentina to 30. The institute stated, "The number of (dead) whales has risen to 30." It added that 26 of the whales were large and 4 were small. Local media had previously reported the deaths of 18 whales. The first carcass was discovered on September 24. Experts are currently working to determine the causes of the incident, particularly investigating the possibility that the whales were poisoned due to harmful algal blooms, as very high levels of biotoxins were found in samples of plankton and bivalves from the area.