JACKSONVILLE, Fla. – Countless hoards of dead cannonball jellyfish are washing onshore near Heckscher Drive. While it’s an unsettling sight, it’s not that uncommon or any real cause for concern.
Jellyfish typically do stay together in large groups, called blooms. Blooms are moved around by large waves, strong winds, and currents. Onshore winds push these blooms closer to our shoreline, and an incoming tide can pull them into the St Johns River.
Cannonball jellyfish have a high water content, and will die if stranded out of water- whether by a dropping tide or a strong wind. Cannonball jellyfish can also be immobilized or killed by cold water temperatures. Our water temperatures locally have dipped into the mid to upper 50s for the last week.
This particular species of jellyfish will not sting you, in fact if harvested while alive is part of the menu in some parts of Asia. There’s no real need to clean up the piles of dead jellyfish, they join the food chain and will be taken care of quickly by crabs, birds, and small fish that can get to them. Leatherback sea turtles make cannonball jellyfish a quick snack.