The lion's mane jellyfish causes most stings in Suffolk County waters, and the common moon jelly can sting too. Two skin conditions get confused with stings: swimmer's itch and sea-bather's eruption, popularly called sea lice.
None of these is common enough to skip the beach, but a quick plan helps. The treatment steps below are the county health department's. For other water-related checks, see the water quality guide.
Jellyfish
The lion’s mane ranges from pink in juveniles to purplish, with a bell from a few inches to over a foot across and tentacles that trail several feet below. The moon jelly is bluish-white with a four-leaf-clover pattern visible through the top of the bell.
Treating a sting:
- Wash the area with seawater or saline. Do not use fresh water, which can make stinging cells fire.
- Apply vinegar or rubbing alcohol to deactivate remaining stinging cells.
- Remove visible tentacles with tweezers.
- Apply shaving cream and scrape off remaining cells with a tongue depressor.
- Use analgesics for pain and antihistamines for itching. See a physician for severe stings.
Sea-bather’s eruption (sea lice)
A rash on covered skin, under swimsuits, shirts and long hair. On Long Island it is believed to be caused by larvae of a sea anemone, trapped under clothing and triggered by pressure. Rinse off and change out of wet clothes soon after swimming.
Packing for it
A rash guard helps. The what to pack guide has the rest, and the calm water beaches guide lists the guarded bay beaches.
Swimmer’s itch
A rash on exposed skin after contact with larvae of bird parasites that cycle through mud snails. It clears on its own, and the county health department takes reports of occurrences.
Questions
Should I use fresh water on a jellyfish sting?
No. Wash with seawater or saline, because fresh water can make stinging cells fire.
What causes sea lice rashes on Long Island?
The rash on covered skin is believed to be caused by larvae of a sea anemone trapped under swimsuits, shirts and long hair.