Lion’s mane jellyfish return to Gulf of Maine
Lion’s mane and moon jellyfish have returned to the Gulf of Maine, with sightings reported in New Hampshire waters according to the Seacoast Science Center and the New Hampshire State Beach Patrol. These creatures, including the large lion’s mane with tentacles exceeding 100 feet, may wash ashore through the end of fall.
Why are jellyfish appearing on New Hampshire shores?
According to Sam Rutka, lead aquarist at the Seacoast Science Center, several species inhabit the Gulf of Maine, including the moon jelly and the lion’s mane. Rutka notes that while these creatures typically stay in deeper, colder water, winds and currents can push them toward the coast.

The moon jelly is characterized by a classic bell shape with small internal circles. In contrast, the lion’s mane is among the largest jellyfish species, featuring tentacles that can grow more than 100 feet long.
What are the operational risks for beach management?
Pat Murphy, chief of the New Hampshire State Beach Patrol, stated that the presence of jellyfish is “one of the things we have to deal with,” though he characterized the current situation as “not a huge issue.”
The primary risk stems from nematocysts, which Rutka describes as tiny stinging cells that act like “little harpoons.” While Rutka stated the animals do not intentionally seek interaction with humans, accidental contact can occur.
How should jellyfish stings be treated?
Experts advise washing the affected area with salt water and applying white vinegar or a heat pack. This treatment addresses the rash and itching sensation, which is compared to contact with fiberglass insulation.
Officials explicitly warn against using urine to treat stings, despite depictions in some television shows. Murphy advised that swimmers should avoid contact with floating jellyfish, though there is no need to alert lifeguards unless a jellyfish has washed ashore.
What may happen next in the Gulf of Maine?
The jellyfish are likely to remain in the ocean through the end of the fall season. Because jellyfish can still sting after death, any creatures washing ashore may pose a continuing risk to pedestrians.
Beachgoers could see continued sightings as weather patterns shift. Lifeguards may need to manage reports of stranded jellyfish to ensure public safety on the sand.
Frequently Asked Questions
What is the best way to treat a jellyfish sting?
Experts recommend washing the area with salt water and applying a heat pack or white vinegar.
Are the jellyfish in the Gulf of Maine aggressive?
No. According to Sam Rutka, they do not want to interact with humans and any stings are simply accidents.
Should I notify a lifeguard if I see a jellyfish in the water?
Pat Murphy stated there is no need to alert lifeguards for jellyfish floating in the ocean, but you should notify them if a jellyfish washes ashore.
How do you handle wildlife encounters during your beach trips?