From Revere to beaches all along the north of Boston coast, Lion’s Mane Jellyfish are turning up in great swaths. Not just north of Boston beaches but the South Shore and Cape and Islands, too. We have been seeing some good sized ones, but this morning’s Lion’s Mane takes the cake and was approximately two feet in diameter. It was glowing fiery orange in the morning sun and that color is what tells you it is a Lion’s Mane. Lion’s Mane Jellyfish are the largest in the world and can grow up to three feet in diameter, with mane-like tentacles that can surpass 100 feet long.Lion’s Mane Jellyfish

In Massachusetts we are most likely to see two types of jellyfish. Moon Jellies, which are saucer shaped and cloudyish transparent white, are virtually harmless. Their tentacles are too weak to penetrate human skin.

Lion’s Mane Jellyfish are found in a wide range of sizes in Massachusetts waters and dead or alive, their stinging tentacles can be very painful.They are not poisonous but the sting of a Lion”s Mane can cause a severe allergic reaction. Tell your kids not to touch the dead ones washed up on the beach and keep on the lookout when swimming.

If stung and any tentacles remain on the skin, remove with tweezers, not your bare hands. Flush immediately in seawater and then rinse with white vinegar. Shower in hot water, or even better, soak in the tub with hot water.  If experiencing an allergic reaction such as dizziness, trouble breathing, headache, nausea, fever, or fainting, call your physician.

When my friend Chris Cefalo finds a Lion’s Mane on the beach, he encircles it to help warn folks to keep away.