Countering algal blooms

Australian scientists have discovered a clay-like compound that has the potential to dissipate algal blooms and lower the risk of poisons entering the water supply and environment. The clay is a cheap, naturally occurring material which, after special treatment, acts to soak up nutrients, especially phosphorus, on which algae depend. Experiments have shown that if a thin layer of clay is spread across the bed of a river or lake, it locks up enough essential phosphorus to prevent algae from blooming. Other laboratory and field trials show that if the clay is sprinkled into a water body in which an algal bloom has already developed, it will strip out enough phosphorus to starve the algae. This technique might allow drinking water storages to be cleansed of algae before they have a chance to bloom _ a method better than the present one, which involves chemical treatment and can leave behind potent algal toxins in the water.