CHARLESTON - Don't look now, but they're out there. Sharks. A lot of them.

They're sneaking up behind shrimping nets in swarms, biting head-size holes in the nets to chomp away on the free lunch of shining, silvery crustaceans. Shrimpers up and down the coast are reporting a slew of them, particularly good-size blacktip sharks, which can grow to 6 feet long.

They're so thick that sportfishing boats are following the shrimp boats around to get their clients a catch, said Shem Creek shrimper Wayne Magwood.

"They're the worst I've seen it in my 50 years of shrimping," Magwood said. "They're just eating the nets all apart."

Meanwhile, pier anglers all along the coast say blacktips are so prevalent that it's sometimes tough to catch anything else, said Mel Bell, S.C. Natural Resources Department fisheries management director.

The numbers are such that shrimpers returning to the Carolina Seafood dock in McCellanville are repeating the old saw "Don't get near the edge," meaning don't stand so close to the boat rail that you might go over, said dock owner Rutledge Leland.

He doesn't know if it's worse than it's ever been, but "they're saying (sharks) are really bad out there. I guess there's nothing out there particularly to thin them out."

Bell tends to concur. It's the time of year when sharks linger offshore, feasting in a warm, food-rich ocean. The fish has become a federally managed species, and its population has been steadily rebuilding after a dive in numbers from fishing pressure in the early 1990s.

It's just hypothesis, he said, but years of tighter and tighter restrictions on catching sharks have thinned out one of their only two predators -- humans. The other predator on sharks is sharks, and in the earlier years of overfishing, larger species might well have thinned out the biggest of that predator too, leaving more young sharks room to grow.

The minimum catch size of blacktips, for example, is 54 inches.

This year, in particular, there was a six-month shutdown on the catch of small, coastal shark species that ended in June, and a six-month shutdown of larger species like the blacktips that didn't end until Thursday.

Sharks aren't strangers to the Lowcountry. The most common shark in the Lowcountry is the relatively small, 3-foot-long Atlantic sharpnose. But some 39 species roam here -- sandbar sharks, blacknose sharks, finetooth sharks, bull sharks, tiger sharks. Even the dreaded great white has been caught as close to shore as the Charleston jetties.

"Seems like it gets worse every year," Magwood said about sharks damaging shrimp nets. Because the boats usually work in sight of the beach, "I can't believe there aren't more accidental bites (of swimmers)."

There have been at least two bites reported so far this year, off Fripp and Otter islands south of Charleston. A small number of bite incidents is reported each year, Bell said.

Reach Bo Petersen at bpetersen@postandcourier.com or 937-5744.