Impact of aluminium on marine life unknown
WHAT level of aluminium is safe, or dangerous, for marine animals? Apparently nobody knows.
CSIRO scientist Dr Simon Apte is one of Australia's leading experts on dissolved metals in waterways.
The Observer recently asked Dr Apte whether the recent levels of dissolved aluminium in South Trees Inlet could be harmful to fish health.
He said there was no reliable data to form an accurate judgment and more research was urgently needed.
"There are only a couple of studies in the scientific literature that have looked at (the impact of) aluminium toxicity to marine fish," Dr Apte said.
"They point to low toxicity (having an impact) but we think there is insufficient data to make a definitive statement on the concentrations of aluminium that would trigger toxic effects in marine fish."
The current "trigger level" for further investigation of aluminium levels is 0.5 ug/L, but Dr Apte says that number is extremely conservative.
In fact, Gladstone Harbour often naturally has levels well above that trigger level.
"The current Environmental Concern Level for aluminium in marine waters (0.5 ug/L) is based on very limited data and is likely to be overprotective," he said.
"Further work is required to conduct more toxicity tests and develop a scientifically defensible guideline for aluminium in marine waters.
"We see this as an urgent need and we are currently doing some of this work at CSIRO.
"We currently don't have the knowledge to say what symptoms a marine fish would display if exposed to toxic levels of aluminium.
"More fundamental research work (is) needed."