Fluoride cycles in an estuarine ecosystem.

The environment of the south eastern section of Kooragang Island shows visible evidence of injury, some of which is attributable to fluorides. Measurements of fluoride concentrations in mangrove, glasswort, seablite, pigface, water couch, house mouse, slaters, insects and soil indicated elevated fluoride concentrations in these components of the Kooragang Island environment, when compared with values obtained at an ecologically similar but relatively unpolluted environment at Karuah. Evidence is presented which indicates that fluorides are transmitted from vegetation to herbivores and on to carnivores along food chains. The possibility of fluoride cycling from vegetation to soils and from vegetation and soils to some elements of the wildlife is discussed. The fluoride concentrations reported are generally in agreement with earlier reports in other studies of fluorides in wildlife in similarly polluted, but climatically different environments, in various parts of the world.