Thousands of dead starfish that littered a beach near Charleston last weekend are the first signs of what might become a disastrous winter for coastal sea life. They died because water was chilled to a lethal temperature by frigid weather earlier this month.

With coastal waters already hovering near critical lows, biologists worry there might be a mass die-off of shrimp, sea trout and red drum as the season turns cold again.

William Gay, owner of Port Royal Seafood, said he has heard Beaufort crab trappers talk about dead shrimp showing up in their crab pots, but said the cold water hasn't yet affected his business.

S.C. Department of Natural Resources biologists also heard reports of stunned red drum and sea trout.

Though Beaufort County is only about 50 miles south of the starfish die-off, water temperatures have been a bit warmer, and the extra warmth has helped.

"It still gets a lot colder there than it does here," said Larry Toomer, owner of Bluffton Oyster Co. "I don't see any signs that would say it's damaged anything or killed anything so far."

Shrimp and other marine life can die off en masse when water temperatures remain in the mid-40s for any length of time. Fisheries biologists watched in alarm earlier this month as water temperature plunged toward that temperature before warming a bit.

"According to my meter, it's 47 degrees," Toomer said. "When we get some sunshiny days, it rises back up."

Computer models predict a few instances of freezing temperatures during the next three or four weeks, said Mark Malsick, severe weather liaison for the S.C. Climate Office.

"We've got to see what these next two months bring, because January and February can be brutal," Toomer said.

How can we reconcile this? The not-so-obvious short answer is that the overall warming of the atmosphere is actually creating cold-weather extremes. Last winter, too, was exceptionally snowy and cold across the Eastern United States and Eurasia, as were seven of the previous nine winters.