Massive Florida Algae Bloom Leads to Accusations
Melissa Block, host:
From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.
There is an environmental whodunit playing out in the Florida Keys. State agencies and environmental groups are working on the case. Their mission, to figure out the source of a huge algae bloom that's threatening to turn 100 square miles of Florida Bay into a marine dead zone.
Here's NPR's Greg Allen in Miami.
GREG ALLEN: Few people spend more time on the water in Florida Bay than Tad Burke. Burke's a fishing guide, in fact the president of the Florida Keys Fishing Guides Association. On this day, the sun is just coming up as he prepares to take Herb Catknacker(ph) and his family out for a day fishing for snook and red fish.
Mr. TAD BURKE (Florida Keys Fishing Guides Association): I'm going to run through the central part of the bay most of the way so we should be fine. (Unintelligible) it's unbelievable.
ALLEN: About a year and a half ago, fishing guides like Tad Burke were among the first to notice that something wasn't right at the northern end of Florida Bay. The normally crystal clear water had turned dark green and cloudy. Scientists confirmed that a huge bloom of blue green algae had taken over a large section of the bay in the area where U.S. 1 crosses from the mainland to the Keys. Burke says for fishermen, the bloom damaged what had been fine fishing waters.
Mr. BURKE: There's not a lot of life in that area. The algae is so thick it actually kind of clogs out the photosynthesis that takes place with the sea grasses. That kind of kills off all of your lower food chain, you know, the small larva crab, larva seahorse, fish larva. And that's kind of what the small fish eat and the bigger fish eat on up the chain.
ALLEN: Environmental groups think they've found a smoking gun, and it's here along the section of U.S. 1 that stretches from the mainland to Key Largo. The Florida Department of Transportation is widening the old two lane road into four lanes. As part of the project, they chopped up dozens of acres of mangrove swamp and turned it into fill.
Peter Freza of the Audubon Society says that fill is a big part of the problem.
Mr. PETER FREZA (Audubon Society): Well, the reason that's a problem is because mangrove leaves are, they're very rich in nutrients - phosphorus, nitrogen. They really pack a lot of nutrients into those leaves. And what that does, you just put all these nutrients into the soil, which is going to leech out into these waters. So that right there, again, you could point the finger at that and say this big release - that could definitely cause an algae bloom.
ALLEN: Florida Bay is beautiful, but it's also a body of water that has long been under stress, the result of agriculture and booming development in south Florida. When environmental groups raised questions about the construction on U.S. 1, Transportation Department officials did measurements and concluded their project couldn't product enough excess nitrogen and phosphorus to account for the bloom. They point instead to a nearby canal under the authority of another state agency that has long been known to carry large amounts of nutrient rich runoff.
For that reason, Transportation Department engineer Alice Bravo sys the agency never considered halting the road project.
Ms. ALICE BRAVO (Department of Transportation): Any possibility of nutrients from the project causing the boom is so small in comparison to other factors, such as the (unintelligible) canal, that I don't think there would be enough cause to take an action like that.
ALLEN: The Transportation Department has agreed, though, to no longer use the mangrove muck in sensitive coastal areas. Jerry Lorenz, a marine ecologist with the Audubon Society, says out in Florida Bay, the algae bloom is smaller now than it was a few months ago. But he says that doesn't mean that it's going away.
Mr. JERRY LORENZ (Audubon Society): It's not really dissipating. We're not seeing it really get any smaller. And now that daylight starts to get longer, I think we're going to see this thing come back with a vengeance.
ALLEN: Lorenz says a big concern is that sea grasses are beginning to die off. Sea grasses are the base on which the marine ecology rests. Once they're gone, he says, sponges, fish and anemone aren't far behind.
Lorenz speaks from experience. Another similar die off occurred in the late-‘80s, in another part of Florida Bay that he says had been glorious.
Mr. LORENZ: It was crystal clear water over these lush sea grass beds. Within a year, that entire basin had been denuded with a mud bottom. The water was discolored. And this persisted to today. It's still - although some of the sea grass is coming back in that area, it's not nearly the way it was in 1989.
ALLEN: At least five federal and state agencies are now investigating their current algae bloom, trying to determine what to do about it. There was one positive development from the last dead zone in Florida Bay. It helped form a consensus to safeguard water quality, leading eventually to the massive Everglades restoration plan.
But among environmentalists and sportsmen, there's a frustration that so far, that federal state agreement has done little to actually improve water quality in Florida Bay and that six years after it was approved by Congress, not one major project has yet begun.
Greg Allen, NPR News, Miami.