Motions

West Beach Marine Life Deaths

The Hon. N.J. CENTOFANTI (Leader of the Opposition) (16:21): I move:

That this council—

1. Notes the multiple and significant deaths of larvae and oyster spat at South Australia Research and Development Institute (West Beach) facility in October and November 2024;

2. Recognises also the significant deaths of both barramundi fingerlings and broodstock from an adjacent private business during the same period;

3. Notes that the operational phase of the Labor government’s Adelaide Beach Management Review Implementation Project began on 3 October and ended on 30 November;

4. Acknowledges that internal pathology testing revealed no pathological explanation for the deaths; and

5. Calls on the Minister for Primary Industries to appoint an independent investigator to thoroughly examine all aspects of the fish deaths, including the private business and SARDI facility inlet pipe location, and any possible seawater quality impacts.

The loss of fish at the SARDI facility in West Beach late last year was widely reported. Approximately 300,000 juvenile snapper and between 75 per cent and 100 per cent of the stock of POMS-resistant oyster spat was lost. Documents released under FOI revealed that a private company, which was a tenant on the site, lost at least 180,000 young fish and brood stock.

There is significant public interest in this issue, as the lost snapper was destined for the snapper restocking program. The loss of 300,000 juvenile snapper represents approximately nine months of restocking, given the numbers being released at that time. The snapper restocking program plays a vital role in sustaining the fish population, supporting the health of marine ecosystems and ensuring the long-term viability of both commercial and recreational fisheries.

By replenishing depleted stocks, such programs help maintain biodiversity, protect the balance of marine food webs, and support the livelihoods of communities that depend on fishing. However the success of these efforts hinges on the survival of snapper larvae, which are highly vulnerable during their early developmental stages. High mortality rates amongst larvae—which can be caused by factors such as environmental changes, predation or disease—can significantly undermine restocking efforts, reducing the number of juveniles that reach maturity and ultimately threatening the program's ability to restore healthy population levels. Ensuring the survival of larvae is therefore critical to achieving the ecological and economic goals of snapper restocking initiatives.

South Australian oyster growers say that the mass deaths of marine life at the SARDI research facility will set their breeding lines back by approximately 12 months. The spat in the breeding lines were being developed to be resistant to Pacific Oyster Mortality Syndrome (otherwise known as POMS), a disease that kills oysters in a matter of hours and which was first discovered in Australia in 2010.

The POMS-resistant breeding line at SARDI is crucial for safeguarding the oyster industry against POMS. This breeding program represents years of dedicated research aimed at developing oyster strains that enhance resilience to POMS, ensuring the sustainability and economic viability of the industry. However, the recent deaths of oyster spat at SARDI poses a significant setback to this vital work. The loss not only delays progress in strengthening disease resistance but also threatens the availability of recent stock for oyster farmers, particularly exposing the industry to renewed vulnerability. Rebuilding these breeding lines will require time and resources, highlighting the critical need for robust biosecurity matters and continued investment in research to protect against future disruptions.

There has been no clear reason given yet for these fish deaths. Laboratory pathology reports recovered under FOI show that there was no evidence of a pathogen. Water testing records did not reveal any abnormal changes in water properties and the absence of an obvious pathogen leads to conjecture in the documents that some type of 'unknown toxic insult' has occurred.

Whilst the snapper, barramundi and oyster are individually managed within the facility, all tanks are supplied via a common water supply. As all tanks are small and juvenile fish were similarly impacted, it seems likely that a common factor caused the fish mortality, and the only factor in common was the water supply.

We cannot ignore the fact that the timing of these fish deaths correlates with the government's beach dredging trial that was conducted between 3 October and 30 November. Part of the trial was conducted along the coast offshore of the SARDI aquaculture facility. Email conversations recovered under the FOI process reveal conversations with SARDI staff clearly questioning DEW staff about the timing and location of this dredging trial at West Beach, where both the dredging site and the sand deposition sites were close to the water inlets for the SARDI facility.

It is clear through that correspondence that people within the department are questioning whether the dredging trial may have had a role in these deaths. It has been stated to the opposition through whistleblowers that an odour of rotten egg gas was evident at this time, which often suggests the presence of hydrogen sulphide.

Hydrogen sulphide can be toxic to small and juvenile fish in low concentrations in water, and hydrogen sulphide can be released from decomposing anaerobic plant matter, such as seaweed. All of the above factors suggest that some sort of influence from the dredging trial conducted by DEW at West Beach that led to fish mortality cannot be ruled out.

The public cost and delay to the fish and oyster restocking program means that it is in the public interest to find the cause of these fish kills. Given the scale of the losses and the potential implications for South Australia's marine industries, an independent investigation into the deaths of larvae and oyster spat at SARDI is essential.

The snapper restocking program and the POMS-resistant oyster breeding lines are critical to the sustainability and economic health of the fishing and aquaculture sectors. The unexplained deaths of these vital juvenile stocks, compounded by similar losses in an adjacent private business, raise serious concerns that cannot be adequately addressed through internal reviews alone.

The correlation between the timing of these deaths and the government's own dredging trial near the SARDI facility further underscores the need for the impartial inquiry. It is important to find out what went wrong and that will not happen with a government department investigating itself, or with one government department investigating another government department.

An independent investigation will ensure transparency, hold relevant parties accountable and help identify any environmental or operational factors that contributed to this incident. This is not only necessary to restore confidence among industry, stakeholders and the public but also to safeguard the future of vital restocking programs that support South Australia's marine ecosystems and its economy.

Debate adjourned on motion of Hon. I.K. Hunter.