Fish killed by red tide litter Sanibel's shores

Sanibel's shores are a haven for those escaping dreary winters, but Thursday they were a mass grave for tens of thousands of rotting fish.

Red tide, caused by Karenia brevis, crept its way to Lee County after festering off Sarasota County for several weeks. Besides killing fish, red tide can cause respiratory irritation in humans and other mammals.

"Some (fish) have been missing their eyes for a while, but you can smell the red tide and cell counts are elevated," said Rick Bartleson, a water quality scientist at the Sanibel-Captiva Conservation Foundation. "The fish probably didn't wash from a distance away. It was most likely pretty close to Sanibel or right at Sanibel."

Recent counts along Sanibel and in Pine Island Sound measured 500,000 to 760,000 cells per liter. It takes about 10,000 cells per liter to start killing fish and be visible from outer space.

Tourists from Toronto, Vermont and Germany alike stepped over piles of dead fish to enjoy the waters of Sanibel.