Woodside and fishing lobby planned to dump structure with toxic chemicals near Ningaloo

A plan to use old oilfield equipment for an artificial reef near Ningaloo Reef in Western Australia could have endangered the health of people who ate fish caught there, according to a federal government assessment.

WA recreational fishing lobby group Recfishwest wanted to sink an 83-metre-long floating steel structure from a shuttered Woodside oilfield 1.7 kilometres from Ningaloo World Heritage Area to be the centrepiece of an artificial reef but later abandoned the plan.

Ningaloo Reef is host to the world’s largest congregation of whale sharks. Credit: Via David Whitley / How Good is Australia

However, the structure, a riser turret mooring, most likely contained dangerous amounts of toxic fire retardant chemicals called PBDEs.

Ningaloo has the world’s largest concentrations of whale sharks, when up to 500 gather as coral spawns. Aside from the more than 700 species of fish, the coast is home to about 10,000 marine turtle nests every year.

The plan was expected to “present a material risk to the marine ecosystems” and “risks to human health cannot be ruled out”, according to Department of Agriculture, Water and the Environment documents obtained with a freedom of information request by the Australian Conservation Foundation.

If the reef was used for recreational fishing as intended, “it would be difficult to exclude potential risks to humans through ingestion,” a January 2021 assessment by DAWE said.

“PentaBDE is known to have associations with loss of IQ.”

Woodside had planned to tow the structure from its Enfield oil field off the north-west coast to shore when production ended in 2018. However, offshore safety regulator NOPSEMA found Woodside had skipped on maintenance and the ballast tanks needed to allow the structure to float horizontally for a long tow no longer worked.

The alternative method of disposal was to tow the 2452-tonne structure a much shorter distance and sink it in deep water where together with 48 smaller purpose-made structures it would form an artificial reef to create a habitat for fish.

Recfishwest, a non-profit lobby group for WA recreational fishers that has supported other artificial reefs, applied to the federal government for a sea dumping licence for Woodside’s structure.

One compartment of the structure is filled with 65 cubic metres of polyurethane foam, which Recfishwest estimated was likely to contain up to 120 kilograms of PBDEs as it was built before an international agreement restricted their use in 2009.

DAWE expected all the foam and flame retarding chemicals would eventually be released to the environment, although it could take many hundreds of years.

The department concluded Recfishwest’s proposal had “substantial uncertainties” and it provided no assessment of the risk to the environment or humans from the contaminants in the structure. A Recfishwest spokesman said it was responsible for the content in the proposal relating to artificial reefs in general and Woodside provided information on its structure.

The proposed use of a Woodside-developed “plastics offset program” described as a “beach clean-up” to remove plastic from the ocean equivalent to the amount in the structure was described by the department as “questionable”.

ACF campaigner Nathaniel Pelle said stronger laws were needed to govern decommissioning.

“We know the industry will try to cut costs at the expense of the environment and the community every time,” Pelle said.

”Woodside has made the mess – and billions of dollars –now it needs to be made to clean up after itself.′

The Recfishwest spokesman said when it became more aware of risks from the foam its support became conditional on its complete removal.

The group submitted a new proposal to cut out the section of the structure containing the foam after it had been laid on the seabed but withdrew it in September 2021 as the project was becoming increasingly complex.

A Woodside spokeswoman said the local fishing community had advocated for a deepwater reef for many years and selected the location and the permit application was by Recfishwest.

A NOPSEMA spokesman said it was investigating whether Woodside had breached the law by not properly maintaining the riser turret mooring. The regulator said Woodside planned to remove the structure to shore by early 2023. It is likely it will be lifted onto a heavy construction vessel.