When a stingray took a swipe at a swimmer off Island Beach State Park this week, a park official likened it to the ocean's version of a dog bite.

"The ocean is filled with sea life. I think a lot of people have lost the concept that the ocean is a living room for thousands of marine species," said Bob Schoelkopf, director of the Marine Mammal Stranding Center in Brigantine, N.J., explaining the official's comment. "People aren't the only things out there."

Indeed, at this time of year with the beaches packed with swimmers, sometimes it's hard to remember the deep blue Atlantic is an ocean, not a pool.

Nearly every summer - just about the time the Jaws musical theme creeps into the idle mind of a sunbather taking a break from a trashy beach read to stare at the sea - someone spots an ominous fin along the Jersey Shore.

Sometimes it's even a real shark.

Locals usually just yawn. But a sighting can send tourists - and the media - into a frenzy, despite the fact that there are plenty of sharks (of several types) swimming out there all the time. Usually they mind their own business, migrating and feeding on other fish.

So on Wednesday, when officials determined that a possible shark sighting in Seaside Heights was likely only a school of stingrays, anxious bathers in the vicinity were relieved.

Then on Thursday, when the New Jersey Department of Environmental Protection reported that a 22-year-old man was taken to a hospital after being stung by a stingray in the shallows of the inlet on the southern end of the park in Berkeley Township. Stingrays have serrated tails that can cause painful lacerations.

Slightly warmer-than-average water might be bringing a greater number of stingrays into the shallows earlier than usual to feed on baby surf clams, which wash up with the tides, Schoelkopf said.

Stingray sightings are not unusual since two species - the southern and the Bluenose - are native to the New Jersey coast and usually congregate there by the hundreds every August, he said.

Besides the stingrays and sharks, a menagerie of other creatures is out there, too: whales, dolphins, crabs, clams, and fish so abundant they could fill millions of aquariums.

Luckily most of the species - including the stingrays - are usually OK with sharing their space with humans.

"But I wouldn't want to step on one," said Schoelkopf, who recommends that swimmers wear wet boots or surf shoes.

And use common sense, he recommends. If you see fins, don't rush out into the surf.

"You wouldn't run into the woods to pet a bear," Schoelkopf said.

Contact staff writer Jacqueline L. Urgo at 609-652-8382 or jurgo@phillynews.com.