Fire retardants and the dying Lakes

Who ever stops to consider what might be in those bright pink fire retardants the DSE dumps by the thousands of tonnes all over our forests, water catchments, houses, bridges and streams almost every summer? In the desperate situation of a bushfire, who wants to know? Certainly not the government.

The plight of the Gippsland Lakes after the ’03 and ’06 fires could well be related to the weeks of retardant dumping in the catchments. After the ’09 fires, Melbourne’s water catchments will be similarly polluted with the unknown hot-pink cocktail. But any impacts will be blamed on the ash and of course “greenies”.

Toxic algae connection

Fire retardants vary slightly in their composition but they all contain fish-killing ammonia compounds. In the US, ammonia compounds make up to 90% of the product, with thickeners, dyes, corrosion inhibiters and attapulgite clay added. This clay compound could well harbour the new type of year-round marine algae, Noctiluca scintillans, which is blooming across the Gippsland Lakes.

This species feeds on detritus, phytoplankton, protozoans and fish eggs. Although this species does not produce a toxin, it has been found to accumulate toxic levels of ammonia which is then excreted into the surrounding waters, possibly acting as the killing agent in blooms. This ammonia stench has made residents feel sick during the height of the blooms.

In the US, federal and state agencies drop between 15 – 40 million gallons of retardant annually and environmentalists and the Firefighters United for Safety, Ethics and Ecology are questioning the over-use of the retardant. A US federal lawsuit is demanding that the fire agency conduct a study of the impact of fire retardant under the Endangered Species Act. In 2002, 20,000 fish were killed after one dump. Endangered salmon are often killed.

Could the ongoing deaths of molluscs and aquatic life in the Gippsland Lakes be connected to the same problem?

Jill/New York Times


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