Mystery ‘Grease Balls’ Washing Ashore in Australia Are Prompting Beach Closures

Strolling along a shoreline may lead to the discovery of seashells, sandcastles, and the occasional crab. It can also result in stumbling across mystery blobs of grease that concern environmental groups and prompt beach closures.

According to The Guardian, several marble-sized balls have washed ashore on nine beaches located in Sydney, Australia. The debris is peculiar in appearance, with a white or grey exterior and a flaky, dark-colored center. Other than appearing organic in nature, they aren’t easily identifiable.

Concerned over that ambiguity, the Northern Beaches Council instructed people earlier this week to avoid Manly, Long Reef, Freshwater, North and South Curl Curl, Dee Why, North Steyne, North Narrabeen, and Queenscliff beaches. They’ve since permitted seven of the nine beaches to reopen.

Regulators, including the New South Wales Environment Protection Authority, are removing the balls and conducting tests to help determine what they are and where they came from.

“We don’t know at the moment what it is and that makes it even more concerning,” Northern Beaches mayor Sue Heins said while addressing the issue on Tuesday. “There’s something that’s obviously leaking or dropping or whatever and floating out there and being tossed around. But who’s actually dropped it or lost it or leaked it is something none of us know.”

One possibility? Disgusting waste. Similar mystery balls appeared on other Australian beaches in late 2024. Testing indicated they were “fatbergs,” lumps of coagulated goo that often include cooking grease, drugs, wet wipes, and excrement found in wastewater discharge. Some fatbergs have grown to sewer-clogging proportions, with one in the UK similar in size to a passenger plane.

At the time, Sydney Water denied that the mini-fatbergs were formed by wastewater discharge and instead suggested they may have been “tar balls” that absorbed some pre-existing waste.

Locals have speculated on the balls. “I saw a few of these balls on our Saturday morning walk on Dee Why beach,” one brave resident posted on the Northern Beaches Council Facebook page. “I dug my thumbnail into one and it smelled a bit like tar.”

“Heard the lifeguards saying it is sewage and oil together that has created these marbles,” another wrote. “That got the swimmers out [but] surfers didn’t seem to mind.”

Test results of these newer Australian grease balls are still pending. In the meantime, Australian authorities have one piece of advice for beachgoers: Don’t touch them.

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