I'm off to Coogee today, where tar balls have been washing up on the beach.
My oceanography colleague Matt England was interviewed and explains where they might have come from:
Hundreds of tar balls have surfaced on Sydney beaches. But what are they? - ABC News
https://www.abc.net.au/news/2024-10-17/coogee-beach-tar-balls-everything-you-need-to-know/104482828


