Ocean Watch

Here's a recent e-mail from an "Oceanwatch" reader in Liverpool, England:

"I have just come back from holiday in Rhodes, Greece. ... I was snorkeling in a beautiful rocky bay and pulled myself through a narrow space between some rocks. ... I felt a stinging sensation on my face. ... My lips swelled up, blisters appeared in three other places and my face felt numb.

"I rinsed in sea water, which did no good, but then I noticed three small, brown, lacy tentacles about one-half inch long, which looked as if they had broken off. Do you think it was a sea anemone? I've been rather concerned about what would have happened if I'd swallowed them or if they had gone in my eye."

Yes, this sting was almost surely from a sea anemone.

Sea anemones look like fleshy flowers and got their name from the European flower Anemone nemorosa, a poisonous, white-flowered plant that causes blisters.

Closer to home is a similar plant, the Japanese anemone, Anemone hupehensis.

People in Hawaii (and other areas) grow this Japanese native for its showy white, pink, red or purple flowers. Like its European cousin, it can also blister skin.

So, too, can sea anemones. They are close relatives of jellyfish and corals and bear similar stinging tentacles.

Some sea anemones move around freely, and some hitch rides on the backs of crabs, but most anchor their backsides to rocks and then wave their tentacles around to sting and eat passing prey. Small anemones eat plankton and tiny bottom dwellers, and large anemones eat fish and crustaceans. None eat people, but these creatures don't discriminate: Touch an anemone and you will be stung.

Not much is known about sea anemone stings. I do know firsthand, however, that some sea anemone-induced blisters can last up to six weeks.

Several years ago, my husband and I hosted a medical student, Maggie, for two months while she studied here. She immediately signed up for scuba-diving classes.

After her open-water dive on the Waianae Coast, Maggie came home with a red, raised hive on her calf the size of a compact disk. In the center of this inflamed spot rose several painful, oozing blisters.

"I brushed against something on a rock," she said, wincing. "What should I do?"

We called my husband, an emergency doctor interested in marine medicine. He knew of no proven treatment. His advice: "Take a picture of it."

Maggie and I proceeded to apply everything we could think of to ease her symptoms, including vinegar, hydrocortisone and antihistamines. Nothing helped. After six weeks she still had scars, and we had some good sting pictures.

People with jellyfish stings to the eyes have recovered with no permanent damage, and hopefully, the same goes for sea anemone stings to the eyes. The treatment is to rinse stung eyes with large amounts of room-temperature tap water for 15 minutes. If symptoms persist, see a doctor.

Swallowing anemone tentacles can be dangerous because of the swelling they can cause. If anemone tentacles get in your mouth and you have difficulty breathing, get to an E.R.

In her e-mail, my Liverpool reader adds, "This won't stop me from snorkeling because I love it, but I'll be more careful around rocks in the future."

Good idea. Wherever you are, on land or underwater, steer clear of anything that contains the word anemone.