Oyster and clam beds in Broad Creek and Jenkins Creek are temporarily closed after a storm pounded Beaufort County on Wednesday.
S.C. Department of Health and Environmental Control spokesman Adam Myrick confirmed the decision was caused by the thunderstorm.
"This is something we do routinely when it rains," he said. "It's in the interest of public health." Broad Creek is off Hilton Head Island, and Jenkins Creek is off St. Helena Island.
Rainfall can wash contaminants such as pesticides and fertilizer, as well as organic matter and the bacteria it carries, into nearby waterways. Because clams and oysters are filter-feeders, they can contain unsafe levels of the contaminants after downpours.
The beds will reopen when "water-quality sampling indicates bacteria levels are suitable for shellfish harvesting," said Mike Pearson of the DHEC shellfish sanitation program.
"This is something that happens a half-dozen to a dozen times a season," said Tonya Desalve of Benny Hudson Seafood on Hilton Head. "It usually reopens in two or three days."
Charles Gay of Gay Fish Co., near where Jenkins Creek flows into St. Helena Sound, said the closure would not affect his business.
"We're not getting anything from that creek right now, so this isn't a big deal at all," he said.
The rainfall might have put a slight damper on shellfish harvests, but it was welcomed for other reasons: Only 0.53 inches of rain fell in the county last month, making it the second-driest April on record, dating to 1893.
Exactly 6 inches more than that total fell during Wednesday's storm, according to measurements taken at the Marine Corps Air Station in Beaufort.