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.
TAD BURKE: 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.
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: Peter Freza of the Audubon Society says that fill is a big part of the problem.
PETER FREZA: 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: For that reason, Transportation Department engineer Alice Bravo sys the agency never considered halting the road project.
ALICE BRAVO: 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.
JERRY LORENZ: 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 speaks from experience. Another similar die off occurred in the late- '80s, in another part of Florida Bay that he says had been glorious.
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: Greg Allen, NPR News, Miami.
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