Bitter cold takes toll on starfish: ISLE OF PALMS — Thousands of dead starfish that littered the beach here last weekend are the first signs of what might become a disastrous winter for coastal sea life. They died because water chilled to a critical, lethal temperature after frigid weather earlier this month.
That didn’t happen last winter until mid-January. This year, coastal waters are already hovering around that critical point, and fisheries’ biologists worry we might face a mass die-off of shrimp, sea trout and red drum as the season gets cold again.
Most of the shrimp trawling water will shut down very early, on Dec. 31, to keep a bigger supply of overwintering shrimp out there, said Mel Bell, fisheries management director.
Along with the starfish, S.C. Department of Natural Resources biologists have heard reports of stunned red drum and sea trout, and weakened or dead shrimp turning up in crabbers’ traps. That’s the kind of reports they were getting last winter when a prolonged cold blast — in mid-January — decimated fish in Florida and threatened fish here.
For that season, DNR closed shrimp trawling on Jan. 10, nearly two weeks earlier than the winter before.
Shrimp and other marine life can die off in mass kills when water temperatures hover in the mid-40s for any length of time. Fisheries biologists watched in alarm earlier this month as water temperature plunged toward that critical point “like it was fixin’ to augur in,” Bell said, and reached it briefly before waters warmed somewhat.
“It’s bouncing right at the critical point right now,” Bell said Wednesday.
In the winter of 2000-01, prolonged water temperatures of about 46 degrees destroyed an estimated 97 percent to 99 percent of the shrimp population, and shrimpers qualified for federal disaster assistance. It took two seasons for the shrimp to recover fully, and five seasons for the sea trout.
Long-range computer modeling calls for a slow moderation of temperatures this winter, with drops to freezing temperatures for at least the next three or four weeks, said Mark Malsick, severe weather liaison for the S.C. Climate Office.
The dead starfish scared Isle of Palms beachwalkers, who have seen a mass die-off for three years in a row now.
“Thousands, maybe tens of thousands” were on the beach on both sides of the mid-island pier, said 30-year resident Jack V. Owens, who walks the beach daily. “I’m relieved it’s temperature related and not something else.” Owens said he hoped the large kills for three years running wouldn’t deplete the population.
Bell said the starfish die-offs probably aren’t frequent or widespread enough to do any serious damage to the population. He said that nearby populations would quickly move in and that the animals reproduce rapidly.
The starfish near the pier got caught by a combination of cold water and rough surf that weakened them so they couldn’t hold their ground on the bottom.
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