AN invasive jellyfish that normally lives in tropical waters has been found in Lake Macquarie, raising concerns about its potential impact on the local ecosystem.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
The Australian Museum this week confirmed the creature shown in our photograph was, indeed, an upside-down jellyfish (cassiopea).
The picture was one of three sent to the Lakes Mail by concerned resident Steve Jones, of Windermere Park, who recently encountered large numbers of the jellyfish in the water near his home.
“My son Darshan and I were just heading out onto the lake in our kayaks when we saw what we thought was a plastic bag floating near the jetty,” Mr Jones said.
“It was only when we lifted it out of the water with an oar that we saw it was a jellyfish.”
Mr Jones said he’d never before encountered such a jellyfish in the lake.
“So when we got home I Googled it,” he said.
“At first I was relieved to read that it wasn’t dangerous. Then I saw that it was invasive, so I was concerned it could cause problems in the lake, and maybe crowd out fish and other wildlife.”
Dr Stephen Keable of the Australian Museum told the Lakes Mail the upside-down jellyfish had the potential to cause problems in Lake Macquarie.
But he said it was too soon to speculate about what, if anything, should be done.
“We need to understand the situation better,” he said.
“Populations of jellyfish are notoriously variable with some crashing completely, so no control may actually be required. However, it would be prudent to investigate.”
He said taking a genetic sample of the specimens found in Lake Macquarie would be the starting point.
“The answer will give us a better understanding of how it may have arrived, and what if any control is necessary and possible, bearing in mind that we don’t discount the prospect of natural events driving a change in a species distribution range,” he said.
This is not the first upside-down jellyfish found in NSW waters.
Dr Keable and his colleague Dr Shane Ahyong have written papers about large blooms of the jellyfish in Wallis Lake, near Forster, and even Lake Illawarra.
“The finding in Lake Macquarie is another piece of the puzzle and will stimulate us to do more [research],” Dr Keable said.
