Unhealthy Port Phillip Bay fish

Latest News - February 8, 2008

Continuing investigations by EPA Victoria have ruled out pollution as the cause of fish with lesions being caught in Port Phillip Bay.

Investigations to date have found flathead, flounder, puffer fish and cobbler with head lesions. Reports from the public indicate that there may be other species affected (including ludrick, bream, trevally and pike).

EPA will continue to support Department of Primary Industries in their endeavor to identify causes however it is unlikely that there is a single cause.

Previous Department of Human Services advice that people should avoid touching or eating any fish that have lesions is still current.

Background

In January 2008 EPA Victoria and Fisheries Victoria investigated reports of fish with lesions being caught in Port Phillip Bay.

The investigation following several species of fish, including flathead, blowfish, whiting and trevally bearing the lesions being caught across a large area.

Department of Human Services advised that as a precautionary measure people should avoid touching or eating any fish that have lesions, or are lethargic and looking generally unwell.

Photos of affected fish (click to enlarge)

The event is similar to incidents which have occurred in the past. Historically these events have passed and fish stocks have recovered.

More information

If you catch a fish with lesions please contact the Department of Primary Industries 24 hour Emergency Animal Disease Hotline on 1800 675 888.

General questions from the public about unhealthy bay fish should be directed to the Department of Primary Industries by calling 13 61 86.

EPA Media Releases

• Investigations underway into unhealthy bay fish. - 17 Jan 2008
• Update Unhealthy Bay Fish - 8 Feb 2008
  

Frequently Asked Questions

Q. What is wrong with the fish?
A. The fish have open sores on the skin (in this case, only on the head region), which is referred to as “chronic ulcerative dermatitis”. Some also have cloudy eyes. This disease can result from a range of toxic, traumatic, bacterial or fungi causes. EPA and Department of Primary Industries looking at each of these origins for a cause.

Q. Has it happened before?
A. Yes it has happened before. Similar diseased fish were found in 1984 and 1992 in areas across Port Phillip Bay.

Q. Did you find out the cause in those cases?
No. Intensive investigations by Department of Primary Industries could find no specific cause. Fish stocks and fish health recovered after each event.

Q. What causes have been investigated this time?
EPA and Department of Primary Industries have investigated water quality parameters (including pH, salinity, dissolved oxygen etc), pollutants (including metals and organic compounds) and toxic phytoplankton (i.e., algae) with the potential to impact on fish in the Bay. The metals that have been assessed include arsenic, mercury, lead, cadmium etc. The organic pollutants assessed included pesticides, polychlorinated biphenyls (PCBs) and poly aromatic hydrocarbons (PAHs) etc. The phytoplankton assessed included known toxic diatoms and dinoflagellates. During these investigations, sampling for fish and phytoplankton occurred from beaches and off boats in an area stretching from Williamstown to Werribee South. All sampling for pollutants and water parameters occurred over the same area and was beach-based.

Q. What do you know about those possible causes?
There is no evidence that any of the pollutants investigated caused the disease in the fish. The key parameters relating to pollution and algal impacts were within normal range. There is no evidence for toxic phytoplankton causing the disease. Although the water is slightly warm and saltier at this time of the year, all water quality parameters are within normal ranges and are highly unlikely to be the cause of the fish disease.

Q. So have you looked at other causes?
Yes. Department of Primary Industries have investigated bacterial, fungal and parasitic causes. Extensive pathology and histology studies of the fish coordinated by Department of Primary Industries showed that no specific causes of the disease was identified.

Q. Will you continue to look for a cause?
As pollution has been ruled out as a specific cause, EPA will continue to support Department of Primary Industries in their endeavour to identify causes. It is unlikely that there is a single cause in a disease like this.

Q. Can I eat the fish?
As a precaution the Department of Human Services (DHS) have advised not to touch or eat fish that have lesions or appear sick in any way.

Q. Is it safe to swim in the bay?
There is no evidence to suggest that the sick fish cause the bay to be unsuitable for swimming.

Q. What if I catch a fish with lesions in Port Phillip Bay?

If you catch a fish with lesions please contact the Department of Primary Industries 24 hour Emergency Animal Disease Hotline on 1800 675 888.

Preferably wrap it in a plastic bag and dispose of the fish in a rubbish bin. If you have a camera, please take a photo of fish at time of capture. Please note the fish species, where you catch (or saw) it and contact the above . Please wash your hands thoroughly in warm water after touching any sick fish.

General questions from the public about unhealthy bay fish should be directed to the Department of Primary Industries by calling 13 61 86.

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