More jellyfish on our beaches could be due to warming seas
Jellyfish. Theyre one of our planets strangest and most beautiful creatures. Famed naturalist and broadcaster Sir David Attenborough once called them the masters of nomadic existence. And in 2022, he was honoured as namesake for a fossil which is thought to be one of the earliest members of the species group that inclues jellyfish and coral: Auroralumina attenboroughii. So its no surprise that when a particularly large or kooky specimen washes up on an Auckland beach, this newsroom hears about it. READ MORE: * TV producers worried Sir David Attenborough would catch bird flu and die during filming * Sir David Attenborough's new UK series, Wild Isles, likely to be last on location * Wellington coast hosts scores of jellyfish as water temperatures rise The biggest and kookiest of the lot? The Lions Mane jellyfish, or Cyanea rosea. Its the largest species that frequents the entire coast of New Zealand and even reaches the eastern Australian coastline. Auckland man Dave Fleming was walking at Bayswater Marina when he spotted a jellyfish. He estimates it measured between 500 and 600 mm across its body. When he got home he researched to see what kind of jellyfish it was, and found old reports that while its common to see Lions Mane around during warm months, a September spotting was unusual. So I thought well, July, August is earlier still. I wonder if the sea is warmer than normal. Hes been wondering that for a while as a regular fisher, Fleming has noticed the sea hasnt been as cold as it typically gets this time of year. In July, the United Nations chief Antonio Guterres warned that the climate change situation has escalated, saying: The era of global warming has ended; the era of global boiling has arrived. July has already seen the hottest three-week period ever recorded; the three hottest days on record; and the highest-ever ocean temperatures for this time of year, he said. The Lions Mane jellyfish sports a bright brownish-pink colour, and the outside of its bell which can get to 2 metres is covered in colourless raised warts, or papillae. Inside the bell there are eight clusters of tentacles, each with hundreds of translucent to whitish, short, curly tentacles arranged in several rows. Individuals occasionally swarm in large numbers in warm summer months in bays and harbours when there is an abundance of plankton to feed on. It is found all over the world in polar, subpolar and temperate seas, and less commonly in tropical seas. Professor Simon Thrush , the University of Aucklands Head of the Institute.of Marine Science said its very normal to find these jellyfish in the ocean, and how many there are partially depends on the climate. With our oceans being warmer than they often are this time of year, and with fewer south-westerlies than typically present in winter, its more likely to see jellyfish on or near our shoreline. Thrush said another factor is how often, and how many humans disturb the sea floor where some species spend much of their lives. That can be one factor that can lead to explosions of abundant jellies, he said. Others can be oceanographic conditions and the kinds of animals that are in the zooplankton, whether they are predating on the jellies or whether the jellyfish are dominant. We do see oscillations over time, [but] there isnt really any good time series on this stuff, its not easy to be definitive about.