Tassal, a foreign-owned aquaculture company, has reported another significant fish kill at its barramundi farm located in Cone Bay, on the Kimberley coast of Western Australia. Recent images and videos taken by a whistleblower and shared by a conservation group show numerous dead barramundi floating in the sea pens. Trucks and earthmovers have been seen transporting and burying large quantities of dead fish at local waste facilities.

Martin Pritchard, director of Environs Kimberley, stated, "What we've had is a whistleblower providing us with images from Cone Bay, clearly showing that this is a really serious mass fish kill happening on Tassal's barramundi sea cages up in the Buccaneer Archipelago." He estimated that between 100 to 150 tonnes of fish have died, based on observed truck movements. However, Tassal has not confirmed this estimate, only acknowledging that there were "lower-than-usual survival rates" at the farm in October. The company attributed the issue to a naturally occurring parasite known as a blood fluke, which it claims was influenced by lower ocean temperatures.

The Department of Primary Industries and Regional Development (DPRID) has confirmed that Tassal experienced elevated fish mortality levels at Cone Bay. The department stated that all affected fish have been removed from the sea pens to mitigate environmental impacts, and the dead fish are being disposed of at approved facilities. DPRID inspectors are working with Tassal veterinarians to prevent further mortality.

Despite the department's assessment, neither Tassal nor DPRID classified the incident as a mass mortality event, and they did not clarify the criteria for such a classification. Pritchard disagreed with this assessment, asserting, "For the average person to look at this, you can clearly see this is a mass fish kill." He has called for an independent inquiry into the situation, emphasizing the need for transparency and accountability from the government.

Dr. Stephen Pyecroft, president of the aquatic animal health chapter of the Australian and New Zealand College of Veterinary Scientists, explained that blood fluke is a parasite that does not pose a risk to human health. It can be treated with a drug called Praziquantel, which is safe for marine environments. He noted that intensive aquaculture practices can exacerbate the prevalence of such parasites, leading to higher mortality rates among fish.

Tassal is currently seeking to expand its operations at Cone Bay, aiming to increase production from approximately 2,000 tonnes to 17,500 tonnes annually. The company has scaled back its original proposal from 13 sites to 7, with plans to place the cages in deeper waters to reduce environmental risks. This expansion requires approval from both the state and federal environmental authorities, with a decision expected next year.

David Williams, former chair of Tassal and current chair of a corporate advisory firm, noted that global aquaculture producers are diversifying their offerings beyond salmon. He highlighted the potential for barramundi in the Australian market, estimating that the annual demand for barramundi could reach at least 50,000 tonnes. Williams acknowledged the challenges of operating in the remote Cone Bay area, citing logistical difficulties in transporting staff and supplies.

Pritchard has urged both state and federal governments to reconsider Tassal's expansion plans, arguing that the Kimberley coast is a globally significant area known for its pristine environment. He stated, "It is not appropriate to be putting industrial fish farms in this incredibly important marine biodiversity hotspot on the Kimberley coast."