Major physico-chemical parameters of four saline lakes (Lake Colac, Modewarre, Bolac and
Tooliorook), in the volcanic plains of western Victoria (Australia), recorded bi-monthly between
November 1999-September 2001 are described. Lakes are permanent, large (surface
area range 3.5-29.6 km 2) and shallow (mean depth range 1.5-3.9 m). Physico-chemical parameters
revealed that lakes were homogenous with few differences between sites within
lakes. Of the four lakes, Lake Modewarre had the highest salinity of 8 ppt with weak seasonal
fluctuations in salinity in all the lakes. All the lakes were turbid (turbidity range 30-659
NTU), with low light penetration (suspended solids range 23-465 mg 1-1) and low Secchi
depth (Secchi depth range 7.7-89 cm). pH of the lakes varied between 8.2-9.3 with low seasonal
variations, indicating well buffered waters. Based on nutrient status, lakes were classified
as eutrophic to highly eutrophic with higher nutrient concentrations. Nitrogen was limiting
in one lake (Lake Colac) and phosphorus in the other three lakes. Meteorological events
probably influence the physico-chemical parameters of these lakes strongly.