Australia: The Land Where Time Began

A biography of the Australian continent 

Dangerous Jellyfish Blooms are Predictable

Irukandji syndrome, which is potentially fatal (Bames, 1964; Southcott, 1967; Williamson, Fenner, Burnett & Rifkin (eds), 1996; Gershwin et al., 2013), is relatively common in tropical waters throughout the world. The Irukandji jellyfish, a family of box jellyfish, the cause of this syndrome, is nearly impossible to detect in the water because of their small size and transparency. In this paper Gershwin et al. used collated medical records of stings and local weather conditions to show that the presence of Irukandji blooms in coastal waters can be forecast on the basis of wind conditions. Blooms largely coincide with relaxation of the prevailing southeasterly trade winds, on the Great Barrier Reef, with average conditions corresponding to near zero alongshore wind on the day before the sting. According to Gershwin et al. these conditions are consistent with hypotheses that have been held by local communities for a long time and are a basis for designing management interventions that could potentially eliminate the majority of stings.

Irukandji stings cause a debilitation illness, with some patients requiring life support, and a significant number of which experience recurring symptoms (Little & Mulcahy, 1998; Macrokanis, Hall & Mein, 2004; Nickson, Waugh, Jacups & Currie, 2009; Fenner & Carney, 1999). There are at least 14 known species of Irukandji, and stings have been confirmed throughout coastal, reef, and island tropical and subtropical waters globally (Gershwin, 2005; Fenner, Lippmann & Gershwin, 2010; Lippmann, Fenner, Winkel & Gershwin, 2011; Gershwin, De Nardi, Fenner & Winkel, 2009) and may increase further with climate change (Richardson, Bakun, Hays & Gibbons, 2009). [Irukandji jellyfish have been found to be moving further south from tropical Australian waters in the East Australian Current as the water warms due to climate change. (MHM)]. Though most stings remain undiagnosed Fenner, Lippmann & Gershwin, 2010; Lippmann, Fenner, Winkel & Gershwin, 2011; Gershwin, Nardi, Fenner & Winkel, 2009 Fenner, Lippmann & Gershwin, 2010; Lippmann, Fenner, Winkel & Gershwin, 2011; Gershwin, De Nardi, Fenner & Winkel, 2009 Fenner, Lippmann & Gershwin, 2010; Lippmann, Fenner, Winkel & Gershwin, 2011; Gershwin, De Nardi, Fenner & Winkel, 2009; Fenner, Lippmann & Gershwin, 2010; Lippmann, Fenner, Winkel & Gershwin, 2011; Gershwin, De Nardi, Fenner & Winkel, 2009, particularly in the developing world, in Australia reported hospitalisations are typically 50-100 per year. The financial impact on tourism and the practical safety implications for marine-based industries, such as fisheries and commercial diving, can be enormous (Gershwin et al, 2013; Anonymous, 2013). An example is the cost of cancelled tourism bookings  following 2 fatalities on the Great Barrier Reef in 2012 have been estimated at more than $US65M (Gershwin, De Nardi, Fenner & Winkel, 2009).

Over many years there have been anecdotal accounts from lifeguards and other beach-users and it was these that raised the hypothesis that stings coincide with periods when northeasterly winds are weakened. This hypothesis was tested by combining medical and environmental data, and this demonstrated significant capacity for forecasting Irukandji blooms.

Sources & Further reading

1. Gershwin, L.-a., S. A. Condie, J. V. Mansbridge and A. J. Richardson (2014). "Dangerous jellyfish blooms are predictable." Journal of The Royal Society Interface 11(96).