Water: Blue-green algae in the Gippsland Lakes - January 2013 - Department of Health, Victoria, Australia

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Blue-green algae in the Gippsland Lakes - January 2013

Blue-green algae in the Gippsland Lakes - January 2013

Blue-green algae (cyanobacteria) species Nodularia spumigena has been detected at some locations in the Gippsland Lakes. This species produces nodularin toxin which can be taken up by seafood.

Health guideline values for blue-green algal toxin in fish and seafood have been derived by an independent Scientific Advisory Group. Human ingestion of seafood with toxins above health guideline values can adversely affect liver function and may cause cancer.

The Chief Health Officer has lifted the advisory warning people not to eat whole fish and seafood (prawns, mussels and crabs) caught in the Gippsland Lakes system.
Test results show that the toxins in whole fish and seafood caused by low levels of the blue-green algae Nodularia in the Lakes at the end of last year have declined to levels that will no longer affect human health.
There is now no risk from blue-green algae toxins in fish and seafood taken from the Gippsland Lakes and all seafood advisory signs around the Lakes will be removed.

Monitoring of algae types and levels in the Gippsland Lakes continue on a regular basis. The Department of Sustainability and Environment provides weekly updates on blue-green algae levels in the Gippsland Lakes.

Further information

Health Risk Assessment for Cyanobacterial Toxins in Seafood

This paper estimates risk from seafood contaminated by cyanobacterial toxins, and provides guidelines for safe human consumption.

The following table provides a summary of the nodularin health guideline values derived for seafood from the Gippsland Lakes.

Health guideline values for nodularin in seafood from the Gippsland Lakes*

Toxin	Health guideline value for nodularin toxin is seafood from the Gippsland Lakes (ug/kg of whole organism sample)
Toxin	Fish	Prawns	Mussels (Molluscs)
Microcystin-LR or equivalent toxins, i.e. Nodularin	24	32	51

* For further information refer to the Factsheet - Health risk assessment for cyanobacterial toxins in seafood from the Gippsland Lakes

Factsheet - Health risk assessment for blue-green algae in seafood from the Gippsland Lakes

Seafood samples are being regularly collected from within the Gippsland Lakes and tested for toxins. The following seafood testing results have been obtained to date:

Results from laboratory analysis of Black Bream fish samples

Date of collection	Sample Location	Level of nodularin toxin in whole fish samples (ug/kg)1	Level of nodularin toxin in gilled & gutted fish samples (ug/kg) 2
24-12-12	Jones Bay	< 16	< 16
27-12-12	Eagle Bay	< 16	< 16
27-12-12	Metung	< 16	< 16
27-12-12	Tambo Bay	< 16	< 16
31-12-12	Eagle Bay	< 16	< 16
31-12-12	Tambo Bay	< 16	< 16
3-1-13	Jones Bay	< 16	< 16
3-1-13	Metung	37	< 16
7-1-13	Eagle Bay	< 16	< 16
7-1-13	Tambo Bay	< 16	< 16
9-1-13	Metung	27.2	< 16
10-1-13	Jones Bay	< 16	< 16
10-1-13	Waddy Point	< 16	< 16
14-1-13	Eagle Bay	< 16	< 16
14-1-13	Tambo Bay	< 16	< 16
18-1-13	Jones Bay	< 16	< 16
18-1-13	Metung	< 16	< 16
18-1-13	Waddy Point	< 16	< 16
21-1-13	Eagle Bay	< 16	< 16
21-1-13	Tambo Bay	< 16	< 16
21-1-13	Metung	< 16	< 16
21-1-13	Jones Bay	< 16	< 16

1 Result derived from composite sample comprised of three whole fish collected from each site
2 Result derived from composite sample comprised of three gilled and gutted fish collected from each site

Results from laboratory analysis of whole mussel samples

Date of collection	Sample Location	Level of nodularin toxin (ug/kg)3
16-1-13	Kalimna Jetty	39.7
16-1-13	Nungurner Jetty	< 30
22-1-13	Kalimna Jetty	< 30