Published: Oct 27, 2010 3:25 PM EDT
Updated: Oct 27, 2010 12:51 AM EDT

BONITA SPRINGS, Fla. - Thousands of fighting conchs are washing up and dying out on the beach. Now, marine biologists are looking into a possible cause for the massive wash up.

It's a sight drawing crowds of people shore-side on Tuesday - Florida Fighting Conchs washing up in numbers, just north of Bonita Beach Access Point 10.

"Never seen anything like this before," Bonita Beach vacationer Rick Hamlin said Tuesday.

Thousands of picturesque shells washed up along a 500 foot span of Bonita Beach, the giant clusters of Florida Fighting Conchs twisting and turning in the sand.

"At first I was pretty excited about it because I come down here looking for shells every year,but then I realized there was something wrong," Hamlin said.

The cause behind the colonies dying out remains a mystery on Tuesday. Marine biologists are waiting on new water samples to shed light on what's causing the massive number of mollusks to wash up.

"I think it's kind of sad to see them all wash up on shore and die out and dry out here on the beach," Bonita Beach vacationer Jeremy Prues said Tuesday.

Marine biologists with Sanibel-Captiva Conservation Foundation say one possible reasoning behind the wash up could be a bloom in algae in the water. A surge in algae activity can soak up oxygen in the water, and lead to problems for some marine life.

Sanibel-Captiva Conservation Foundation's Marine Lab says there were high levels of algae about a month ago, creating undesirable conditions for the conchs. Still, for the past two weeks, they say water samples at Bonita Beach have turned up clear. As they wait for answers, those shore-side are left at a loss at what's causing the sand to be spotted with the picture-perfect shells.

"I wondered if it didn't have something to do with the oil spill, especially after I smelled the soap odor on the shells," Hamlin said.

Inspectors from the Lee County Environmental Engineering Division are scheduled to take water samples at Bonita Beach on Wednesday. Marine biologists can then test the water for different kinds of pathogens.