LEWES, Del. — More beachgoers have been getting an unexpected shock this summer as jellyfish numbers bloom along the Delaware coast, interrupting — but not stopping — the summer fun.
Beach patrol captains reported a dramatic increase in jellyfish activity and stings in July, the most they’ve seen in recent memory. Lewes Beach reported a fourfold increase in stings compared to 2024.
Lion’s manes, which can have 100-foot (30-meter) tentacles, sea nettles and moon jellyfish are some varieties that frequent Delaware’s summertime waters.
Jellyfish blooms have become common from Maine to Florida in recent years. Warming waters can create ideal conditions for jellyfish growth.
Normally, Delaware’s five state parks may report a handful of summer jellyfish stings, said Bailey Noel, a beach patrol captain. But Fenwick Island State Park recently reported 92 stings on a single July day. Three lifeguards were taken to urgent care after swimming in jellyfish-infested waters, Noel said.
The jellyfish at Delaware’s Towers Beach surprised Philadelphia resident Christina Jones, whose two daughters refused to wade back into the water after being stung, she said.
“The jellyfish are pretty bad,” Jones said. “And not only are they a lot in number, but they’re pretty big.” Delaware State Beach Patrol started tracking jellyfish stings this year due to the rise in cases, said Noel. Most patrol teams do not track the data.
Lewes Beach Patrol treated 295 stings in 2024, the first year the data was collected, but reported over 1,200 cases so far in 2025, said Capt. Strohm Edwards. Lifeguards started carrying vinegar solutions, which can neutralize the venom agents, to help ease pain, he said.
But vinegar solutions may cause microscopic venom-coated barbs known as nematocysts to discharge, according to some research. Those experts recommend a baking soda slurry.