The Stingers of La Niña
Tropical Cyclones Anthony and Yasi, passed over Hayman Island on 30 January and 2 February, 2011. One year on and trees that were stripped of their leaves and bark remain a ghostly reminder of nature’s fury. Cyclones and La Niña events that have affected us on the Sunshine Coast have filled Lake Eyre, flushed the ailing Coorong and rejuvenated Australia’s largest river ecosystems. Were it not for the alternating fortunes of La Niña and El Niño events, eastern colonization of the Pacific Ocean from Asia to Easter Island would have been improbable by ocean going outriggers.
On Hayman Island, there was the wow factor from 33,000 plants and 327 new species landscaped by Jamie Durie. Irene and I had taken a Jetstar deal to celebrate our 14th wedding anniversary and we did our bit for the recovery of tourism in tropical Queensland. We donned our obligatory stinger suits, spent 2 hours snorkeling around Blue Pearl Bay and watched the return of scuba divers being followed by hundreds of fish like pied pipers of Hayman. My stinger suit was the brightest thing in the water on the day.
Highlight for the day? A 250 – 300 kg Queensland groper at the Hayman marina is familiar with the return of the boats and we were witness to a raised awareness as the fishing charter boat came in at 4:00 pm. The morning fish feeding uses barramundi pellets but the fishing charter crew offer the real deal and the groper and giant trevally are attuned to the difference.
With the stinger season coming to a close in March, I was curious to know if La Niña events of recent years have affected the distribution of Irukandji. Sustained northwesterly winds off the Coral Sea deliver bluebottles (Physalia utriculus) and by-the-wind sailors (Velella velella) that sting swimmers and surfers. They can be in numbers enough to leave the high tide line blue on Sunshine Coast beaches and Fraser Island. In 2002, 58-year-old British tourist, Richard Jordon, was stung by Irukandji while swimming near Hamilton Island. He died several days later. The tiny but deadly Irukandji jellyfish was believed not to stray further south than Gladstone but they were discovered in the waters of Hervey Bay in March 2007 and caused Warner Bros to stop filming a movie.
I asked Jamie Seymour of James Cook University for some images of Irukandji and if La Niña events have had any influence on the southern limit of their distribution. Jamie has documented his own envenomation and recovery while researching the stinger, but he has no data to suggest an impact on the distribution of Irukandji by La Niña related events. Jamie suspects that they are further south than the confirmed presence off Fraser Island. I invite you to do your own research while continuing to wear my stinger suit until sunshine fades the fluoro.
Meanwhile, the 2011-12 La Niña event is nearing its end. According to the Bureau of Meteorology, sea surface temperatures across the central tropical Pacific Ocean are now near-normal and the Southern Oscillation Index (SOI) has been in the neutral range since late February. Central Pacific trade winds weakened mid March and cloudiness near the Date Line has returned to more normal levels. The beginning of the “classic” La Niña events were 1910, 1916, 1917, 1938, 1950, 1955, 1956, 1971, 1973, 1975, 1988 and 1998. I need only look at the call on me as a dive leader to know that we are in the third successive La Niña year. The stinger for me is that La Niña events have kept me out of the water. When life is diving and all the rest is surface interval, I can say that I am genuinely grateful for the three week series on THE GREAT BARRIER REEF. It had me dreaming of dives to come and there was the rush from spotting the sequences when I was actually there with Richard Fitzpatrick and the BBC team as scene scout and safety watch.
Let’s go diving this autumn and winter.