Microcystins associated with Microcystis dominated blooms in the Southwest wetlands, Western Australia
Kemp, A., & John, J. (2006). Microcystins associated with Microcystis dominated blooms in the Southwest wetlands, Western Australia. Environmental Toxicology, 21(2), 125-130. doi:10.1002/tox.20164
Potentially toxic cyanobacterial blooms are becoming common in the freshwater wetlands on the Swan Coastal Plain, Western Australia. During summer the dominant bloom-causing species belong to the genera Microcystis and Anabaena and to a lesser extent Aphanizomenon and Nodularia. Although toxic cyanobacteria have been recorded in the Swan-Canning and Peel-Harvey estuaries in Western Australia, very little is known about the blooms in the surrounding freshwater lakes. In this study, a total of 32 natural bloom samples representing 13 lakes were analyzed by HPLC for microcystin (MC)-LR, -RR, and -YR. Twenty-eight samples proved to be toxic. The highest total microcystin concentration ranged from 1645 to 8428.6 μg L-1, and the lowest concentrations were less than 10 μg L-1 with some below the detection limit (< 0.05 μg L-1). MC-LR (100%) was the predominant microcystin, followed by MC-YR (71.4%) and MC-RR (60.7%). The presence of a Nodularia spumigena bloom in the freshwater Lake Yangebup was associated with the detection of nodularins (1664 μg L-1). This is the first study to demonstrate the presence of microcystins and nodularins in urban lakes on the Swan Coastal Plain, Western Australia.
peer-reviewed, cyanobacterial blooms, Microcystis aeruginosa, Nodularia spumigena, microcystin, nodularin, freshwater lakes, Western Australia