150 to 200 stings a day have been recorded since late July at Rehoboth Beach, while Lewes Beach is averaging about 100, as heavy jellyfish concentrations keep many swimmers and even lifeguards out of the water.
Warmer air and water, drought-driven higher salinity, seasonal winds and favorable circulation created a “perfect storm” for jellyfish, Delaware Sea Grant said, with a quiet hurricane season also allowing more jellies to accumulate near shore.
Rehoboth lifeguards say this summer’s stings are harsher than in past years—pain can last a full day, and some small children have vomited after being stung.
Lion’s mane, Atlantic sea nettle, moon jellyfish and sea walnut are among the species officials are tracking; they advise vinegar and hot water treatment and urgent care for stings to the face or neck.
The surge has emptied stretches of beach and may foreshadow more frequent outbreaks as rising temperatures and droughts increasingly favor summertime jellyfish.