Incoming weather has brought an increased presence of the Portuguese Man o’ War jellyfish into Horseshoe Bay, the Department of Parks has advised.

Swimmers are advised to take extreme care: the jellyfish, the tentacles of which can trail quite far from the floating blue or purple bladder, cause intensely painful stings.

Portuguese Man o’ War should be avoided when they wash up as well, as their stings remain potent for a significant length of time outside of the water.

A purple flag will be flown at the popular beach, with lifeguards also posting signs.