Florida’s Red Tide Crisis: Which Dive Spots Are Affected

A red tide is devastating southwest Florida's marine life, and thus the state's dive industry. Scientists believe the red tide, comprised of the plankton karenia brevis, is the culprit behind hundreds of dead sea turtles found along Florida's Gulf Coast. The bloom has varied in intensity and distribution, but at times it has stretched from Tampa Bay down to the Florida Keys, and is now threatening to move northwards to St. Petersburg. Governor Rick Scott declared a state of emergency in seven counties on August 13.

A common annual occurrence, red tide is caused by an overgrowth or accumulation of microscopic algae and often occurs in brackish or marine water, but not freshwater. The organism occurs naturally, but many water-quality scientists believe blooms now last longer and with more intensity, thanks to activities like farming and coastal development. It's the 11th month of Florida's red tide event and the state's longest continual bloom since 2006. The scientists think the cause of this red tide is water flowing from Lake Okeechobee, which formerly drained naturally through the Everglades, but is now being redirected to the coast through land reclaimed for sugar production.

More than 200 dead sea turtles, including loggerhead and Kemp's ridley, were found in Sarasota and Collier County waters in July; the Associated Press reported a tally of 300 a month later. The numbers are probably much higher, because most dead turtles decompose and sink in the ocean before they are washed ashore.

Other casualties include thousands of fish, goliath groupers, rays and even manatees - in early August, police in Venice pulled the 80th dead manatee found in local waters this year. Florida wildlife officials say the bloom also killed a 26-foot whale shark that washed up on Sanibel Island.

So how is it affecting the diving? Mark Maddox of Scubavice Dive Center in Fort Myers told Undercurrent business was down about 20 percent. "It's really miserable, a really horrible time," he said. "We don't know how it's going to affect business in the long run."

Maddox says Scubavice sometimes organizes shore dives from Venice Beach but, "It's like a bouillabaisse out there, with so much dead fish and the occasional dead turtle, too."

Troy Sorensen of Dive Florida in Bradenton told us that they currently have to travel four to five miles offshore to find clear water, and they're unable to do shore dives, thanks to the stench of dead fish. Scuba Outfitters in Naples are taking their divers down to the Florida Keys or the Atlantic coast.

Conditions aren't as bad farther north, apparently. At Jim's Dive Shop in St. Petersburg, Teresa Hattaway said there was no sign of the red tide in their area. Further north, Narcosis Scuba in Tarpon Springs said it has not really affected them.

The general consensus is toxic algal blooms are harmless to divers underwater, especially if you are diving offshore. Shore dives can be more difficult. The stench of dead critters, not to mention dead plankton itself, can affect smell-sensitive divers, who may have trouble breathing.

Researchers are experimenting with various ways of killing the toxic algae but are proceeding cautiously because they don't know what effects it could have on the ecosystem.