When Sea Creatures and Swimmers Meet in the Summer Waves

July 19, 2010— -- With the unforgiving summer sun bearing down on many parts of the country, hundreds are flocking to their nearest beach or coastline for relief. But they are being met by an frightening array of sea creatures, including sharks, jellyfish and sting rays.

The latest encounter happened this past weekend when 13-year-old Kendall Parker was attacked by what doctors at Cape Fear Hospital believe was a sand tiger shark near Wrightsville Beach, North Carolina. She reportedly had to get 40 stitches along her arm and may still need surgery to repair a damaged tendon.

"We probably get one or two [patients] a summer," said Carolyn Fisher, a spokeswoman for New Hanover Regional Medical Center, of which Cape Fear Hospital is a part. "I wouldn't say it's common."

Up the coast in Massachusetts, a fisherman caught and tagged a 15-foot great white shark, while in New Jersey, there were five shark sightings in three days.

"The ocean is a vast wilderness, home to thousands of awesome and wonderful wild creatures, and when you visit the beach this summer, you are a guest in their environment," the National Oceanic and Atmospheric Administration (NOAA) says on its website. It also notes that "the majority of ocean creatures are harmless to people, but some animals can and occasionally do injure humans."

Do the Stingray Shuffle?

While injuries can be rare, they have been surfacing this summer caused by a variety of marine life. Over the course of just two days last week, about 80 swimmers were stung by stingrays along La Jolla Shores in California.

"[It] may be an effect where [the stingrays are] not used to the folks in the water like they are right now," said Sgt. John Sandmeyer, a San Diego lifeguard.

The fish, which are named for the barbed stinger on their tails, have venom glands on their underbelly. Though rarely fatal, stingray attacks can be very painful, with several of last week's victims needing to be hospitalized.

"It's pretty bad right between my toes," said one victim.

Stingrays, which normally are not aggressive, do tend to lash out if stepped on, which is why beachgoers are being advised to do the "stingray shuffle," in which they shuffle their feet through the sand to scare off stingrays.

There are an estimated 1,500 stingray injuries reported each year, but California officials say they expect many more this summer as stingrays approach the shore to feed on crabs.

Sea Nettles at Bay

Also making their way up to eat is the sea nettle, which is a type of jellyfish. Warmer temperatures attract zooplankton, which is common in the jellyfish diet. Also, these sea jellies tend to emerge when the water temperature reaches anywhere from 78 to 86 degrees, despite also having the capabilities of living in extremely cold temperatures.

One of the more popular regions for the sea nettle during this time of year is Chesapeake Bay. The Chesapeake Bay Office of NOAA has even created a map on its website that shows visitors where the highest concentrations of sea nettles are.

Elsewhere, there have been so many jellyfish that they've clogged cooling equipment at nuclear power plants, partially disabled an aircraft carrier, and even sunk a fishing trawler whose net was weighed down by them.

Some scientists are attributing the recent outbreak of jellyfish to water temperatures. If the temperature of the ocean rises just a fraction of a degree, the jellyfish will begin reproducing.

"They can produce thousands [of jellyfish] at a time," said Liz Haan, a marine biologist at the Adventure Aquarium in Camen, New Jersey.

Jellyfish are remarkably hardy creatures. They have no bones, blood or brain, yet have survivied for half a billion years. With no claws or teeth, their strength lies in their tentacles, which are packed with venom. That venom can explode with the speed of a bullet.

And because they are so adaptable, able to survive in extremely cold or hot temperatures, scientists say they are quite possibly taking over the ocean.