Gulf St Vincent, South Australia (Samarasinghe and Lennon 1987 7; Samarasinghe et al. 2003); Spencer Gulf, South Australia (Nunes and Lennon 1986)) and several smaller ones (e.g. small estuaries in South Australia and Western Australia; dry tropical estuaries of Queensland, wetland pools of the dry tropical–subtropical zone (Sheaves et al. 2007; Sheaves and Johnston 2009)). In South Australia, about onethird of the 33 estuaries sampled by B. M. Gillanders and T. S. Elsdon (unpubl. data) showed inverse salinity gradients during summer when precipitation and freshwater input declined relative to winter. The classic example of extreme inverse salinity gradients with reduced freshwater input is the Coorong estuary (see below).