1 ABSTRACT A combination of modern genetics techniques and microscopy were used to identify which species of blue-green algae (cyanobacteria) can produce the toxin cylindrospermopsin in water storages used by the coal mining industry. Prior to this research project, the only known toxin producing cyanobacterium found in relation to industrial sites in Central Queensland was Cylindrospermopsis raciborskii. Large culture collections were established in both Adelaide (AWQC) and Rockhampton (CQU) to facilitate detailed research on problematic species from the Central Queensland region. However, the species isolated are known to occur throughout Australia, including the Hunter Valley. During this project, the toxins cylindrospermopsin and oxycylindrospermopsin were always identified when Cylindrospermopsis raciborskii was present. Total cylindrospermopsin concentrations ranged from 0.2 to 22.1 μg L-1. Aphanizomenon ovalisporum was also found to produce this group of toxins. A highly toxic strain of A. ovalisporum was identified from the Isaacs River region. During intensive genetic survey in the field, the toxin microcystin was also identified and this was associated with the presence of Microcystis. Microcystin concentrations ranged between 1.7 to 3200 μg L-1. The species present was genetically not Microcystis aeruginosa but was morphologically similar to Microcystis panniformis. Following unusual genetic results associated with Aphanizomenon and Limnothrix- like material early in the research, additional testing for unknown protein synthesis inhibiting toxins was added to the protocol. The presence of new toxins was identified as a result. This report details the new toxin producing species and includes a photographic guide to their identification.