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2 Feb 07
Algiers Beach becomes Algae Beach
Water infestation troublesome for Sanibel, Lee
By Kevin Lollar firstname.lastname@example.org
Ruth Higgins was appalled earlier this week by the dense carpet of drift algae at Sanibel's Algiers Beach. Thirty feet wide in places and 2 to 3 feet deep, the algae stretched for miles, clumped and matted like red dreadlocks. Walking on the squishy, springy mass was a little like walking on a water bed.
"I've been coming here since before there was a causeway, and I've never seen anything like this," said Higgins, 86, of Buffalo, N.Y. "I don't like it at all. It's very disappointing. This is not the Sanibel I knew as Sanibel."
Brian Lapointe, of Harbor Branch Oceanographic Institution in Fort Pierce, was more excited about the algae. "I'm fortunate that I came over to Sanibel today. This is by far the worst I've ever seen on Sanibel," said Lapointe, an algae expert.
Sifting through the mass, Lapointe rattled off the names of 15 different species of algae. While green algal species were in the mix, the most by far were red drift algae — informally known as "rolling moss."
County scientists started seeing thick coats of red drift algae on artificial reefs late last spring. Turbulence caused by strong weekend winds probably tore the algae on the beach from the reefs.
Red drift algae should not be confused with red tide: Red drift algae are macroalgae that can be seen with the unaided eye. Red tide is caused by a microalgae and is visible only through a microscope. It produces a powerful toxin that can kill marine life and cause respiratory problems in people.
While scientists don't know what causes red tide, they do know that nutrients, mainly nitrogen and phosphorus, flowing into coastal waters can cause massive blooms such as red drift algae.
Such blooms have been getting worse in Lee County over the past three years. Sources of nutrients include treated sewage and fertilizer from agricultural lands.
"After the hurricanes of 2004, a big slug of nitrogen flowed into coastal waters," Lapointe said. "You have a fast-growing area with a lot of sewage. Also, the Caloosahatchee is draining ag lands, and you have water from Lake Okeechobee, which gets nitrogen-rich water from the Kissimmee Valley. So with the sewage and the ag runoff, you get a double whammy."
Lapointe has been studying the effects of increasing nutrients on algae in the Florida Keys since 1983. He's working with Lee County to determine the sources of the nutrients feeding blooms such as red drift algae. Tarpon Bay Lapointe had come to Sanibel this week to look at Tarpon Bay after he heard that it was suffering from a drift algal bloom.
Ralph Woodring, 70, who was born on Sanibel, said the rolling moss is bad. "Nobody's catching any fish at all," Woodring said. "We had a little bait: Some glass minnows came in and stayed a couple of days and then left. We had a run of mullet a few weeks ago, but they left. There ain't any birds because there's nothing for them to eat.
"We have a lot of shrimp and crabs, because there's nothing to eat them. Everything else is in damn short supply."
Woodring said the bay is crawling with an unusually large number of sea hares — shell-less mollusks that eat drift algae.
Water in the bay should be murky, Woodring said, but it's been surface-to-bottom clear for months, which is a problem: Drift algae need sunlight, and they get plenty of it in clear water.
A main concern in Tarpon Bay, as anywhere during such a bloom, is that the algae smother turtle grass, which is important to fish and other marine life. In addition to the proliferation of drift algae in Tarpon Bay, Lapointe noticed that shoal grass, which flourishes in nutrient-rich water, was replacing the turtle grass.
"It's important how nutrients control the functions of coastal systems," Lapointe said. "You go from a seagrass system to an algae system, which provides a lot of food for herbivores, but the algae grows too fast for the grazers to keep up."
While red drift algae clog Tarpon Bay, which is part of the J.N. "Ding" Darling National Wildlife Refuge, a nasty green alga is fouling much of the refuge's other waterways.
The stuff showed up more than a year ago and never left. "During the growing season, it grows incredibly fast," refuge manager Rob Jess said. "It has established itself, so it takes less nutrients. We've seen our seagrass beds decline by half in the past two years. The fishing is down. The mullet aren't here. The wilderness area has been tremendously devastated."
Jess said the algae is a mess. "We're in a long-term decline," he said. "If this continues, we're going to have a sterile environment out here."
At the beach Lapointe came to Sanibel to see Tarpon Bay but heard that Algiers Beach was awash with algae and had to check it out. He spent 90 minutes at the beach, collecting samples and explaining the phenomenon to curious tourists.
Retiree Doug Hoek, 54, of Grand Rapids, Mich., was interested in the nutrient connection. "Up North we have lakes, and they say, 'Add fertilizer, and you get seaweed,'" he said. "Yeah, we're real disappointed. We like the beach. We don't go swimming, but this sure doesn't look very appetizing."
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