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. AP Video shot by Mingson Lau