MERCURY in the Gippsland Lakes and Catchment

In 1978-79 the Fisheries and Wildlife Division of Arthur Rylah Institute carried out a study into heavy metals in the biota and sediment of the Gippsland Lakes. The research was published in 1980.

They found that the concentrations of mercury in the sediment of the lakes had increased to the point where lakes King and Victoria were significantly higher than tests reported from other parts of the world. The study found relatively high concentrations of mercury throughout the lakes sediment and biota, and authorities were alerted to the risk of redissolving or resuspending mercury by dredging or by increasing pH (salinity).

The study identified the load of mercury in the catchment from historic sources to be in the order of 130 tonne. Goldmining (76t); Australian Paper Mill (14t) and coal fired power stations (40t) that also have a continuing input at more than 2 tonnes per annum into the lakes’ catchment.

No action was taken on the report recommendations.

Mercury laden fish has been a long lived political hot potato

In 1998 Gippsland Coastal Board retained the CSIRO to review the water quality of the Gippsland Lakes. The Audit reported that; “The mercury problem does require further investigation, as the evidence indicates rising mercury levels in fish; and sediment concentrations are approaching alarmingly high levels”. Later the report recommended, “Further investigation and research on mercury sources, sinks and cycling is required to enable more effective management of what might be a public health problem”.

Again no action was taken by responsible authorities.

In 1999 a study was published by Fabris titled “Mercury and organochlorins in black bream; Gippsland Lakes”. Fabris stated “The main concentration of mercury in black bream is now 58% higher than that recorded in 1978”.

He further reported “Mercury emissions from coal fired power stations is now thought to be responsible for the elevated levels in methyl mercury detected since 1980. Investigation is required as there is potential for mercury levels in black bream to increase further if atmospheric deposition from coal burning is the major source of mercury to the Gippsland lakes”.

In 2007, nine dolphins were reported to have died of mercury poisoning. Another seven dolphins are known to have since died. The total dolphin deaths are now approximately 30% of the lakes dolphin population, considered to be around 50. In 2010 the lakes’ dolphins were identified as a new species. Now sadly the responsible scientist has lost her funding to continue her dolphin research in the Gippsland Lakes.

The results of these studies highlight potentially serious human health risks, and it is of concern that the recommendations to conduct further investigation have been ignored. The risk of mercury exposure during pregnancy is of great concern because the unborn baby is particularly vulnerable to brain damage and various other health related issues from the toxic effects of mercury.

Possibly the new Ministerial Advisory Committee will have the resources and commitment to constructively manage these issues.

 

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