FISH AND MARINE ANIMAL DEATHS

The Hon. R.P. WORTLEY (14:59): I seek leave to make a brief explanation before asking the Minister for Agriculture, Food and Fisheries a question about the fish and marine animal deaths in South Australia.

Leave granted.

The Hon. R.P. WORTLEY: In response to the fish and marine animal deaths in South Australia, the government has set up a team of experts to investigate the reasons for these deaths. Will the minister update the chamber on recent developments identified by this team of experts?

The Hon. G.E. GAGO (Minister for Agriculture, Food and Fisheries, Minister for Forests, Minister for Regional Development, Minister for the Status of Women, Minister for State/Local Government Relations) (14:59): I thank the honourable member for his most important question. As I have previously advised honourable members in this place, a team of experts has been working extremely hard to get to the bottom of the fish and marine animal deaths in South Australian waters—this fishy problem, Mr President.

I am pleased to advise that recently-obtained satellite images sourced from NASA have confirmed that the fish kills across South Australian waters are most likely caused by increased water temperatures and naturally occurring algal blooms. Scientists who formed part of the team of experts sourced these images to confirm their original theory based on satellite imagery from the CSIRO.

The NASA satellite data confirms the presence of unusually warm water and high chlorophyll levels, which indicates the presence of algal blooms, and it identified those in both gulfs during March, coinciding with fish deaths. In addition, the government's expert team has advised me that analysis of sea surface temperature indicated that the water is 3° to 5° warmer than climatologically average for March.

Working from their preliminary data, the government's expert team continued to persist in narrowing down the causes of these fish and marine deaths, and all reports of fish and marine animal deaths were investigated. Where possible, fresh fish were collected for diagnostic testing, with samples sent to the state's veterinary lab at Glenside (VETLAB) for pathology and histology testing.

The pathologist looked for evidence of disease and pathogens such as bacteria, parasites and viruses that may explain the deaths. The diagnostic tests for the fish samples collected have ruled out infectious fish diseases. Further to this, pathology results have indicated gill irritation consistent with unusually high water temperatures and algal blooms. Water samples were also collected by staff from Primary Industries and Regions SA (PIRSA) at each fish kill location to gain more information on water quality and phytoplankton.

I understand that no known toxic alga have been identified; however, a well-known algae that is harmful to fish, Chaetoceros, has been observed in water samples, and I am advised that this is a known cause of fish kills around the world. Apparently it attaches to the gills, particularly of small fish, and irritates the tissue. The tissue then inflames, and the effect that it has is that the fish suffocates.

Mr President, we do know that the majority of the dead fish are bottom-dwelling small-bodied species which are unlikely to be able to move out of their territory when water conditions deteriorate. Scientists have also been able to rule out that these fish and dolphin deaths are related to a point source pollution event. This is due to the geographical spread of mortalities and the fact that the deaths have been ongoing over several weeks over a very wide range of areas.

I am advised that any pollution event associated with this activities would likely dilute to the point where they have no impact before travelling any significant distance, let alone the hundreds of kilometres over which these kills have taken place. In addition, the EPA has categorically ruled out—categorically ruled out—any link to the desal plant. The outlets of the desal plant and surrounding water are monitored multiple times of the day, and the results demonstrate full compliance with EPA licence conditions. In fact, I don't think it is just the day; I think it is over a 24-hour cycle every single day. I am advised that this data is publicly available on the EPA website.

In relation to the death of other marine animals, I can advise that most of the dolphins that have been recovered have received a post mortem at the South Australian Museum by a collaborative group of pathologists, veterinarians and biologists. The dolphins examined at the museum are photographed and measured, and then undergo a full post mortem. Many samples are collected, including liver, kidney, brain, muscle, heart, etc. The samples are collected for pathology and are studied immediately using a variety of tests such as histology, bacteriology and toxicology.

The results received to date show that the cause of death in five cases was a virus called the morbillivirus, which is specific to dolphins. I understand that this is a natural virus and outbreaks occur from time to time, with surviving animals developing immunity. Obviously, the young animals are particularly vulnerable because their immune systems are not as highly developed as adults', and of course most of these deaths have in fact been babies or juveniles.

I am advised that this virus is transmitted by close contact between dolphins, particularly between mothers and newborns, and this virus cannot be transmitted to humans. I am further advised that it is unlikely that the disease would be able to survive in the environment outside of an animal for any significant length of time. PIRSA and DEWNR advise that this virus has previously been found in overseas dolphin populations and in Queensland and Western Australia. Further test results will be returned in batches over this week and next, and the results obviously will be made public as they become available.

I would like to take this opportunity to thank the government's team of experts, led by chief executives of PIRSA and DEWNR, who through their extreme hard work and dedication over this last month or so have been working tirelessly to get to the bottom of these fish and marine deaths. I would also like to make some special thanks to Vic Neverauskas, a fellow who has spent more of his time under the water in these last number of weeks than above it. He is the manager of aquatic health at Biosecurity SA, and I want to thank him very much for his extremely valuable contribution.

Since the first fish deaths were reported, Vic has been out there collecting samples right across the state. He has been in the water, diving to collect evidence of fish behaviours and responding wherever he possibly could to public concerns. In addition, in conjunction with my parliamentary colleague the Hon. Mr Hunter, I would also like to thank the SA Museum and the University of Adelaide for their contribution and all their agencies and organisations who have contributed to the work of the government's expert panel.