Tiny, invasive jellyfish have been spotted in a Saanich lake but, according to experts, there’s no risk to the public.
A non-indigenous species of warm-water jellyfish native to China has made itself at home in Killarney Lake in Mount Work Regional Park, explained Florian Lueskow, a researcher and PhD candidate at the University of British Columbia.He studies soft-bodied zooplankton in the north pacific and, this spring, he used social media to enlist the public’s help searching lakes across B.C. for freshwater jellyfish.
In early August, a student from the University of Victoria reached out about a possible sighting at Killarney Lake and Lueskow was quick to reply. After searching the water, they found several small, translucent jellyfish widely distributed through the lake.
At first glance, these jellyfish look like tiny, circular pieces of plant, he said, but a closer look reveals active, thumbnail-sized jellyfish with long tentacles, Lueskow explained. This species – which has yet to be named – was first reported in B.C. in the ’90s and has been seen at Killarney Lake annually since at least 2017.
He noted not only is it “very special” to see jellyfish in lakes – there are only about 40 known species of freshwater jellyfish compared to thousands of saltwater species – it’s rare to find this particular species this far north as they only bloom when water temperatures reach about 21 C.
It’s unclear how these jellyfish arrived at Killarney Lake as they’re native to one river in China. Lueskow wonders if they were transported on the surface of a boat, a waterbird’s foot or even with fish during a lake restock.
No matter their origins, these jellyfish are harmless to people as their sting can’t penetrate human skin, Lueskow explained. However, their effect on the Killarney Lake ecosystem remains unclear and that’s what he’s hoping to find out.
The Capital Regional District confirmed there is no risk to people or pets but emphasized there are several other invasive species in parks throughout the region that may pose a health risk.
Park-users are asked to abide by the North American aquatic invasive species prevention program, Clean Drain Dry, which asks that everyone wash any plants, animals or mud off their watercraft, drain all water from boats and gear and dry everything off while on land.
Anyone who spots freshwater jellyfish in B.C. is invited to contact Lueskow and his PhD supervisor, Evgeny Pakhomov. Information and photos can be sent to firstname.lastname@example.org.