Health
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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)

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

3 Composite sample comprising 100 g of mussels collected from each site

Chief Health Officer Alert Blue - green algae in seafood from the Gippsland Lakes 23 January 2013

The department's Chief Health Officer has issued a Health Alert in relation to the algal toxin affected seafood in the Gippsland Lakes.

Useful resources

NHMRC, 2008, Guidelines for Managing Risks in Recreational Water.National Health and Medical Research Council.

Water Quality Research Australia, 2010, Management Strategies for Cyanobacteria (blue-green algae): A Guide for Water Utilities.

Victorian Government health information on blue-green algae.

Mulvenna et al. 2012 Health Risk Assessment for Cyanobacterial Toxins in Seafood International Journal of Environmental Research and Public Health