Forget Sharks, Watch Out for Stingrays, Jellies

LONG BEACH, California, July 23, 2002 (ENS) - The greatest threats to California beachgoers in these warm months are jellyfish and stingrays. Sharks are a distant third, says Dr. Christopher Lowe, assistant professor of biological sciences at California State University, Long Beach.

A marine biologist, Lowe specializes in elasmobranchs - sharks, skates and rays - as well as game fishes. He says these sea creatures often move closer to shore during warmer months.

jellyfish

This purple striped jelly fish is one of the many types of jellies that appear and vanish throughout the year along the California coast. (Photo by Kip Evans courtesy Monterey Bay National Marine Sanctuary)
Jellyfish pose particular problems because they can be hard to see. "They get stirred up in the waves and the person gets stung and never sees the jellyfish," says Lowe. "Generally, its sting is characterized by a light, tingly sensation that gradually builds into a burning sensation that tends to be localized where the tentacles make contact with the person's skin."

Jellies "can have tentacles that can be very, very long - 30 to 40 feet when they're extended - so a person can be swimming along, get stung by a tentacle and never actually see the jellyfish," explained Lowe.

As for treatment, "Often when people get stung, they have a tendency to rub their skin, and quite often when they do that, they just smear the tentacle over more of their skin surface. If you see the jellyfish, the best thing to do is to try to gently grab the tentacle - ideally with something other than fingers - lift it off and flick it away. People recommend trying to use a credit card or piece of cardboard to scrape it off without smearing it over the skin," Lowe said.

Because the toxin is topical, vinegar is a good treatment, Lowe recommends. "You can use ammonia as well as Adolph's Meat Tenderizer. These will neutralize the toxin and take away the burn," he says.

Getting stung by a ray is a more serious matter, especially if encountering a congregation of them. During the summer, stingrays move inshore and are most commonly found in estuaries, bays and along calm sand beaches, Lowe explains. "So the most likely places people encounter them would be if they were swimming at a bay beach or along a calm, sandy, muddy shoreline. They can aggregate in very, very large densities."

When stepped on, a stingray whips up its long, barb-tipped tail.

"A quarter of all stingray-related injuries reported in the United States occur at little tiny Seal Beach," says Lowe. "For locals who have lived here for a long time, it's commonly called Ray Bay."

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Seal Beach attracts thousands of people to its annual sandcastle building contest. Summer 2000. (Photo courtesy Seal Beach Chamber of Commerce)
Lowe researches the reasons for the high stingray population at Seal Beach. It may result from the breakwater off the Long Beach coast, which reduces shoreline wave action from around Seal Beach to San Pedro.

The San Gabriel River has several power plants that dump warm water effluent into that river, and that warms the water at Seal Beach, making it attractive for these rays, Lowe says.

Development of many of our bays and estuaries into marinas has reduced the natural habitat for the four types of stingrays found along California's nearshore - diamond ray, round ray, butterfly ray and bat ray.

"So what we've done at Seal Beach," Lowe says, "is, that through urban development, we've created a super habitat for some of these stingrays, and unfortunately, it just happens to be the same super habitat that humans like to go surf and swim and play in."

"In summer, we believe the rays are coming in to mate, and later in the summer, females are probably giving birth to their pups; rays give birth to live young," said Lowe.

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Bat ray in California waters (Photo credit unknown)
"The females might be staying in the warm water to speed up their gestation rate so their pups will develop faster. So the places where people are most likely to encounter them are when they're walking around a shallow bay area through water that might only be a meter deep."

The best way to avoid getting stung is to do what Lowe calls the "stingray shuffle" sliding one's feet through the sand and under a ray. This will generally cause it to swim away without lashing its tail.

Stingrays are found right in the surf, and they also congregate just beyond the breakers. "A lot depends on the surf," said Lowe. At places with milder waves, "we found stingrays right into the surf zone. By having that flat body, they kind of stick to the bottom and don't get tumbled around. But that's right in the place where people can't see very well and as they're walking through, that's probably when they'll accidentally step on one. But once you're just beyond that zone is where we tend to find the greatest densities."

Unlike the gradual sting of a jellyfish, "As soon as somebody gets stung, they're going to know it, because it's a barb that actually penetrates the skin and creates a wound," said Lowe.

"Something has actually poked into your skin and there is mucus that covers the barb. Embedded in that mucus covering are toxin cells, so as the barb punctures the skin, it causes those cells to rupture and the toxin leaches into the individual's skin," is how he explained the pain.

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Dr. Chris Lowe (Photo courtesy California State University)
"The first thing the individual should do when they're stung is to do their shuffle back out of the water and try not to get stung again," Lowe advises, "because quite often people hobble and when they do that, they take the chance of being stung again. You've got to think of it like going through a minefield. These animals are very social and tend to congregate. People ought to try to go back out the way they came in."

"The general treatment is, first of all, make sure the wound is clean," he said. "They should make sure the barb is no longer in there. The little barbs allow it to get wedged in, but when it pulls out, it pulls out a little bit of flesh and that helps rupture those toxin cells."

In rare case, if the puncture is deep, the spine will actually pull out of the ray and get embedded in the individual's skin. Then a medical dcotor should remove it.

"In most cases it's just maybe a quarter of an inch or smaller that penetrates the skin - just a quick poke is all it takes. It's extremely painful. It's not uncommon to see the toughest surfer dude weeping," Lowe observed.

"As long as it's clean and there are no bits of spine left in there, the best treatment is hot water - as hot as they can stand it. That helps denature the toxin. The general treatment should last an hour or more."

For any type of beach injury, it's best to seek medical attention from lifeguards who have the necessary training and equipment. The greatest concern is for individuals with severe allergies to stings. "Those people can go into anaphylactic shock and that's why for some people, getting treatment right away is important," said Lowe.

He advises such people to carry their anti-sting epinephrine medication. "It's something people don't think of taking to the beach."

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Stingray (Photo credit unknown)
Lowe and his team of student researchers have been involved in discovering ways to help reduce stingray injuries. "In Seal Beach, the city has been looking at ways of reducing injuries to the public, and they've tried everything from eradication to translocation - trying to move as many as they could.

Since none of these efforts were successful or were considered to be ecologically reasonable, so Lowe proposed was stingray barb-clipping program. "The barb is similar to a fingernail; it's basically a modified scale," Lowe said. "It doesn't have any nerves leading to it, so you can clip off the pointy end."

But after two years of clipping the barbs of about 2,000 stingrays, Lowe and his student team found that these rays replace their spines every late summer to early fall. A new spine grows in, the original spine falls off, so at no point are these rays really without a spine.

Lowe has concluded that the barb-clipping technique will not work at the scale that they were doing it. He now believes that "the answer is better education."

For more information on Lowe's research, visit: http://www.csulb.edu/web/labs/sharklab