From Malcolm Robb
In the article on killing algae with clay spray it is stated that the clay sticks to itself
(15 January, p 16).
This is in fact incorrect. The modified clay does not have the stickiness of the unmodified
clay and therefore does not form a cap on the bottom of the river.
A cap on the bottom is undesirable since bioturbation by benthic organisms is
important to move the PhosLock clay through the porewater zone of the sediments.
The clay does not act as a barrier but as an active phosphorus scavenging agent
in the sediment and will hold the bound phosphorus even under anoxic conditions
with no disruption to benthic organisms.
Western Australia
