An anomalous cluster of Irukandji jelly stings (Cnidaria: Cubozoa: Carybdeida) at Ningaloo Reef

WA Museum Records and Supplements | Updated 7 years ago

INTRODUCTION – An unusually large number of cases of Irukandji syndrome were reported in the northern regions of Ningaloo Marine Park (north of Coral Bay) and into Exmouth Gulf in the period March to June 2013. Seven confi rmed sightings of three species of Irukandji jellies were also made during this event (Figure 1, Table 1). The purpose of this communication is to document this event and to provide preliminary information on the ecological context and medical implications.

Irukandji is the common name for numerous types of cubozoan jellies, and for the systemic illness caused by their stings (Williamson et al. 1996; Gershwin et al. 2013). The initial sting is typically mild, but after a delay of some 5–40 minutes, the syndrome onsets with a number of debilitating symptoms including severe lower back pain, nausea and vomiting, diffi culty breathing, cramps and spasms, a feeling of impending doom; some cases also include life threatening hypertension.

Two species of Irukandji are currently known from Western Australia, both from the Broome region (Gershwin 2005). Seasonal clusters of stings have occurred in the Broome region for many decades, typically reported from inside Roebuck Bay through December each year, and then from the more exposed Cable Beach from February to June (Macrokanis et al. 2004; Gershwin et al. 2013).

The earliest cases of Irukandji syndrome reported in Australia were from Onslow in 1927 (Stenning 1928), long before the syndrome was named. Ningaloo Reef, however, typically has few or no sting reports each year. It was therefore unexpected when 23 people were hospitalised with Irukandji syndrome from this region in April–June 2013. A comprehensive study on the drivers and implications of high latitude stings is warranted to determine if this novel event is likely to recur.