‘Irukandji’ jellyfishes pose a major risk to human health and enterprise. These mostly small and venomous cubozoans cause Irukandji syndrome, which can be fatal. At Ningaloo, a fringing reef in Western Australia, Irukandji jellyfishes interfere with a significant whale shark tourism industry. Anecdotally, sightings and stings are more common in offshore waters beyond the Ningaloo reef slope, and are most numerous from February to May. Tools and strategies to address the risks of these species are paramount; however, their size, transparency, irregular distribution, and potent venom make them difficult to study using traditional methods. This project is using quantitative PCR to investigate spatial and temporal distributions of Irukandji jellyfishes at Ningaloo and tests the hypothesis that they are most prevalent offshore and in Autumn. Water samples are being collected at multiple locations, at four distances from shore, including sites within the lagoon and up to 9kms offshore. Samples are being collected three days in each calendar season, over two consecutive years. This project will also confirm which cubozoan species are present and new species-specific primers and probes will be developed and tested. Target species have been collected, their DNA extracted, and the 16S genome partially sequenced using existing universal primers.