Jellyfish, Stingrays Abound; Bathers Urged to Do the Shuffle

Lifeguards at San Diego beaches have some old but appropriate advice for summer visitors to the surf and sand: Stay on your toes, keep your head above water--and do the stingray shuffle.

Beach-goers this summer are sharing the shores with higher-than-usual numbers of jellyfish and stingrays, and the three aren’t always compatible, lifeguards say.

At least 125 swimmers, waders and surfers at San Diego city beaches last weekend were stung by jellyfish. About 79 of those became victims Sunday at La Jolla Shores. As many as 31 people visiting Ocean Beach last week surprised a few stingrays, authorities reported.

On Monday, as many as 15 people at Mission Beach were stung by jellyfish in a two-hour period. During a typical Saturday or Sunday, about 20 visitors to that beach get a rude reception from the invertebrate.

Jellyfish Are Back

“Years ago, there were a lot, but, for a long time, jellyfish just disappeared. Now, all of a sudden, we’ve had lots of them,” said Darrell Esparza, a lifeguard at Mission Beach. “Stingrays always seem to be around.”

While people are driven to the sand and surf by warm weather, so too are stingrays, who migrate in summer toward warm-water currents near the sand and the hatching ground of sand crabs, their favorite food. The rays, flat and about the size of a frying pan, rest on the sand floor and feed in the currents--and aren’t threatening until stepped on.

Then the barbed tail of the stingray whips into action, usually hitting a person’s ankle or foot.

“You can virtually walk right into the water and into a (feeding area), maybe 5 to 10 feet off the sand,” said Bruce Robinson, a lifeguard at Ocean Beach. “It only takes a millisecond for the tail to come up.”

The increased presence of jellyfish is more difficult to explain, authorities say. Small, clear jellyfish, marked by a clover-leaf pattern in their centers, normally are seen in shallow beach waters or washed up on shore by waves or tides. Common also are pelagia, bluish, bell-shaped jellyfish.

But beach-goers this summer also are being stung by another type of invertebrate: rhopilema, jellyfish with a deep purple or maroon color that are sometimes one-third bigger than their more usual cousins.

“We’re not sure why they’re here. They are really not well understood,” said Bob Snodgrass, head aquarist for Scripps Institution of Oceanography. The number of jellyfish, which commonly live in cold water, could be increased near the shore or on the beach because of more forceful waves and tides, or more nutrients in the warmer surface waters, he said.

Pelagia and rhopilema, like most jellyfish, have tentacles with small, stinging cells at the end, Snodgrass said. When a swimmer or wader steps on or brushes by the invertebrate, the cells, as a natural defense mechanism that also is used to sting prey, act like arrows connected to a spring, injecting poison into the surface of the person’s skin.

“They can sting for a long time even after they’re dead,” Snodgrass said.

The effects of the often tumultuous relationship between man, jellyfish and stingray are not alarming, lifeguards say. Jellyfish stings usually cause an itchy rash or small red bumps on the skin, but can be treated quickly by dabbing the area with alcohol or ammonia. The rash shouldn’t be rubbed or scratched, because that could activate more poisonous cells.

Stingray stings usually cause a single puncture on the ankle or foot and must be washed out with very hot water--a painful but short and necessary process to flush the poison from the wound. Barbs from the tail occasionally become embedded in the skin and must be removed carefully, Mission Bay lifeguard Esparza said.

Neither kind of wound is overly threatening. But beach-goers allergic to bee stings, if stung by a jellyfish or stingray, should seek treatment immediately to avoid more serious reactions, lifeguards warn.

Run-ins and run-ons with the marine life can be avoided, they say. To escape the stinging tentacles of jellyfish, surfers and swimmers should watch for jellyfish floating on the water’s surface or tangled in kelp. Beach-goers also should avoid dead jellyfish on the sand, whose tentacles are still active.

The strategy for avoiding stingrays?

“The stingray shuffle,” said Ocean Beach lifeguard Robinson. “We advise people to shuffle their feet as they go into the water, and that stirs the rays from the sand. People usually march right into the ocean and step on stingrays. If they did the stingray shuffle, they wouldn’t have that problem.”