Mysterious dark spheres on Sydney beaches identified

Black grimy spheres washed up on several Sydney beaches have been confirmed to be “tar balls” – toxic lumps of congealed oil and debris – that possibly came from an oil spill or seepage from a ship.

Randwick City Council said preliminary test results from samples collected from Coogee Beach on Tuesday afternoon revealed the material was a hydrocarbon-based pollutant consistent with the makeup of tar balls. Hydrocarbons are the main components of petroleum-based products.

Coogee Beach and nearby Gordons Bay remain closed while a clean-up operation is under way for what council said were thousands of tar balls.

Coogee Beach is closed after mysterious dark balls washed ashore on Tuesday.Credit: Janie Barrett

The lumps, which the council described on Instagram as “mysterious, black, ball-shaped debris” and “dark spheres”, were about the size of golf balls and were spotted by council lifeguards at Coogee on Tuesday afternoon.

On Wednesday, similar balls were found at Gordons Bay, a popular swimming and snorkelling area north of Coogee, and Maroubra Beach to the south of Coogee. Only a few balls were found at the northern end of Maroubra and the beach has remained open.

Randwick Mayor Dylan Parker said the council had engaged an expert occupational hygienist and a specialist waste removal contractor who started removing the debris on Wednesday afternoon, a process that would stretch into Thursday.

“Our community is rightfully very protective of our natural environment and this has been a very concerning incident,” Parker said.

Council lifeguards at Coogee Beach found a small oil slick on Wednesday morning.Credit: Janie Barrett

“Our priority as a local council is to keep people safe and protect as far as possible our coastal and marine environment.”

Council workers collected the black balls into piles above the high-tide line on Tuesday evening and onto the back of a truck on Wednesday following advice from the NSW Environment Protection Authority. The Ports Authority and Transport for NSW are also part of the response.

An EPA spokesperson also took samples for testing on Wednesday, and a spokesperson said this was not yet complete.

While the scale or origin of the pollution incident is not yet known, lifeguards on jet-skis found what they believed to be a small dispersed oil slick off Coogee Beach on Wednesday morning. This masthead later saw a Port Authority vessel in the area.

Black balls have also been washed ashore at Gordons Bay.Credit: Janie Barrett / SMH

Further north, Waverley Council beaches remained open and there were no reports of black balls. The NSW government’s Beachwatch website reported that the water was polluted and unsuitable for swimming at Bronte and Tamarama, but this was because of stormwater run-off.

Northern Beaches Council and Sutherland Shire Council both confirmed nothing had been washed up on their beaches.

A close-up of the black balls on the back of a truck as the clean-up operation progresses.Credit: Janie Barrett

Australian Marine Conservation Society oil and gas campaign manager Louise Morris said oil pollution in the ocean came from both offshore oil rigs and ships. Some petroleum products formed tar balls, while others were more likely to dissipate, but in either form it was a toxic pollutant that harmed marine life.

“We only see a small amount of what is going on because most of it will fall to the bottom of the ocean,” Morris said. “It’s out of sight, out of mind, but it’s being absorbed by marine life, some of which humans eat.”

Professor Ian Wright, a water scientist at Western Sydney University, said the source could be discharge from a ship, which burns diesel, or “an oilier, sludgier sort of fuel that’s more like asphalt”.

He said similar pollution incidents could occur through the stormwater or sewerage systems, for example, if hot asphalt fell into a drain or if people put oil or grease down the sink and it formed “fatbergs” with solids in the wastewater.

The closure of Coogee on Wednesday interrupted daily swimmers and a PE class for Brigidine College Randwick.

Hans Visch, 76, is part of a group of swimmers who normally swim to Wedding Cake Island every morning. Visch saw news of the balls being washed up, but tried his luck on Wednesday morning, hoping it had reopened.

He was horrified by the pollution, given there were whales and other marine life in the area.

“It makes me really sad to see this happening,” he said.

Members of the public who find these balls in other locations should call the NSW Environment Line on 131 555.

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