Irukandji on the move

I was first alerted to the potential southern migration of Irukandji jelly fish during hearings before the House of Representatives inquiry on climate change and the coastal zone in 2008. It was quite a startling revelation to think that what was one of the most poisonous creatures on the planet was on the move from its northern Queensland base towards southern areas. Is this one of the key indicators of climate change around the Australian coast?

Alan Millar of the NSW Botanical Gardens has documented the southern migration of a range of marine algal species for many years. Species that once had a home in SE Queensland now have their northern limits in Northern NSW. There are changes to the species mix extending into Victoria and Tasmania. CSIRO scientists are also familiar with these trends and there has been an association with warming of the East Australian Current (EAC). Coastal waters offer no barriers to natural migration. Observations of changes in distribution are very useful in testing hypotheses of impacts of changing ocean temperatures and other factors on marine and nearshore biota.

Jamie Seymour of James Cook University has been at the forefront of research on Irukandji. Jamie has forcefully argued that we must take seriously the issue of southern migration of this animal given that its sting can not only cause great pain but also death. He has associated its more frequent appearance near Fraser Island to warming trends of the EAC which he attributes to climate change. There is little doubt in his mind that more research is needed on the biology of Irukandji, especially links to critical water temperatures at which it can survive or die.

What is alarming is the recent incidence of people being stung near Fraser Island. The shallow and somewhat warmer waters to the west of the Island now appear to favour the species. John Sinclair has noted these incidents in his regular Fraser Island reports. The concern is of course how much farther south will this tiny deadly animal migrate. When will we see it in the waters of the Sunshine Coast? This is a question that may have serious consequences for the tourist industry of the region. It appears obvious to me that we urgently need to know more about Irukandji biology. But we should also improve methods on how we treat the effects of being stung. As Jamie has said, just as we know more now on how to treat snake bite than we did 30 or some years ago, we must find better ways to reduce the pain and suffering from the stings of this jellyfish.

Words by Prof Bruce Thom. Please respect Bruce Thom’s thoughts and reference where appropriately: (c) ACS, 2017, posted 12th January 2017, for correspondence about this blog post please email admin@australiancoastalsociety.org