Experts gather to monitor the cleaning process after authorities closed down Coogee Beach to the public in Sydney on October 16, 2024. Hundreds of mysterious black tar-like balls have washed up on a popular Sydney beach, prompting lifeguards to close the strand to swimmers. "Mysterious, black, ball-shaped debris" began appearing on Coogee Beach on October 15 in the afternoon the local mayor said, leaving flummoxed authorities scrambling to find out what they might be, and where they may have come from. (Photo by Saeed KHAN / AFP)