An unseasonably strong breeze has been blowing out of the east for almost a week now, keeping the mosquitoes and the no-see-ums off balance and allowing their prey an unusual nocturnal respite. Gusting over and through the hardwood hammock that separates this bayside harbor from the Atlantic, the breeze carries its own reminders. It's a thin echo of the killer wind that tore through those same trees two years ago this month A the wind that stripped leaves and limbs and brought the ocean crashing ashore over most of this island, that drove two-by-sixes through walls and cracked concrete house pilings, that crushed buildings like beer cans, that went on to take 43 lives and do more than $30 billion in damage on the mainland in South Florida and Louisiana. But it's an echo nonetheless, a little cue for the mental-flashback horror film.
Hurricane season has come again to Biscayne National Park. Two years ago the reefs and offshore islands of this mostly marine sanctuary -- the rock and jungle of Elliott, Adams, and Totten Keys, and the sandy anchorage at Boca Chita Key A met the leading edge of Hurricane Andrew, the most devastating storm in American history. Looking down at that moment from the safe vantage of a satellite, you would have seen the storm poised like a giant buzz saw, about to take a bite out of South Dade. Elliott Key would already be turning to sawdust. When the hurricane's eye came ashore a few hours later, the swirling cloud-wall marking its northern boundary passed a quarter mile to the north of the park's northern border; the southern edge of the eye crossed a quarter-mile south of the park's southern boundary. The center of the eye rolled directly over Elliott Key -- ground zero for a natural destructive force more powerful in its own way than a thermonuclear bomb.
After the storm passed, the people who know Biscayne National Park best -- the rangers and researchers who spend their days in the bug-filled hammocks and on or under the waters of the bay and ocean, those who keep an eye on this unique wilderness in the shadow of Miami -- had problems of their own to take care of. Some had been forced to flee homes and labs on the bay's islands; many had lived in Homestead, now a waterless, powerless swath of rubble. Those able to get their lives sufficiently together to think about the park could only expect the worst.
They had good reason to worry. In 1980 a glancing blow from Hurricane Allen had utterly wrecked the coral reefs of Jamaica's Discovery Bay. In 1988 Hurricane Gilbert had stripped whole forests on the Yucatan peninsula, burning with lightning-set fires much of what survived its winds. And in 1989, Hurricane Hugo had decimated the Francis Marion National Forest in South Carolina, turning thousands of acres of trees into toothpicks. Hurricanes aren't gentle with things -- man-made or natural -- that try to stand up to them. For buildings, reefs, and trees alike the rule is simple: If something sticks up, the storm does its powerful best to knock it down.
In Biscayne National Park, there was plenty to get knocked down. Extending fourteen miles into the Atlantic from its eastern boundary on the South Dade mainland, the park encompassed the upper reaches of the 360-mile-long Florida Reef, a fragile ribbon of living coral perched in shallow water at the northernmost limits of their tropical range. Stunningly beautiful and rich in marine life, the Biscayne reefs harbored cultural and historical wealth as well: dozens of shipwreck sites, dating as far back as the Eighteenth Century. On the bay islands -- once reefs themselves 25,000 years ago, and more recently the haunt of Indians, pirates, and pineapple farmers -- dense hammocks of West Indian hardwoods thrived
in one of the United States's few genuinely tropical ecosystems. The islands' western coasts were narrowly fringed with mangroves, their roots swarming with baby fish. Beyond, on the bottom of the bay, a seagrass Serengeti stretched to the horizon. And along the mainland shore, north of the ominous towers of Turkey Point and south of the incongruous mega-midden of the South Dade Landfill, a second, larger mangrove forest rose, rooted in muck that had been supporting its trees for thousands of years.
The park was a natural resource rendered priceless by scarcity, by South Florida's relentless appetite for coastal real estate. And now it seemed Nature had chosen it as a zone of self-mutilation. Instead of blowing through the beachside condos and hotels farther north like an agent of ecological vengeance, Andrew had stomped ashore across one of the last surviving pockets of Old Florida. From a certain perspective -- if you were able to get by the thousands of lives and homes saved by the storm's southern landfall -- it almost didn't seem fair. Not fair to Elliott Key, so blasted by the storm that one researcher wept on returning; not fair to the elkhorn coral offshore, ripped branch from branch; not fair to the big mangroves, their three-foot-diameter trunks snapped like uncooked spaghetti, lying twisted in vast blowdowns on the west side of the bay.
Then again, Nature doesn't know from fair. Nature knows systems, checks and balances, feedback loops. And in these latitudes, Nature -- at least that part of Nature that builds and sustains coral reefs, tropical hammocks, and mangrove forests -- knows the hurricane intimately. The two have a long history together. So it should come as no surprise that the story of the meeting between Biscayne National Park and Hurricane Andrew doesn't end in devastation, that these two systems, one creative and one destructive, might interact in a manner more complicated than simple collision.
That interaction continues today. Wildly, chaotically, the park is recovering, at a pace that amazes those who remember the wreckage of two years ago. Once skeleton-bare, Elliott Key's upland hammocks now look like the resting-place of a giant green amoeba. An entire new forest of mangrove seedlings has shot up head-high between the rotting hulks of Andrew's victims. And offshore the elkhorn coral reefs have shown amazing resilience -- not only surviving the storm but actually thriving in its wake. For biologists and park visitors alike, Andrew's impact on Biscayne has ceased to be a disaster and has become an opportunity -- a chance to watch natural South Florida at work, renewing and rebuilding. Divided but not quite conquered by development, down but not quite out, its restorative power retains the ability to awe. Hurricanes, at least, it knows how to handle.
Nowhere is that more apparent than from the elevated deck of the Elliott Key visitors' center. Looking down at the verdancy of the resurgent trees, festooned with fast-growing vines and leaves springing straight out from limbless trunks, it's hard to imagine the battlefield desolation that park maintenance machinist Fred Kopf found when he returned to the island after the storm. Kopf had battened down the buildings on the Keys only hours before Andrew hit. Out at the Elliott center two years later to continue with hurricane repairs, he remembers that afternoon as pretty much like this one, a bright, calm summer day without the slightest hint of approaching danger. The only problems he and his boss, Mike Jester, ran into were on Adams Key, at the building called the Casino. Built by Carl Fisher in 1917 and once part of the Cocolobo Club, favorite fishing hideaway of Richard Nixon and Bebe Rebozo, the Casino housed artifacts recovered from shipwrecks on the Biscayne reef -- cannonballs, swords, and other piratical swag. Kopf and Jester had planned to remove the exhibits from their cases and bring them back to the mainland for safekeeping. But there was one hitch: They had the wrong keys for the cases. With the storm bearing down on them and buildings still to be boarded up, they left the cannonballs in the Casino.
Had they had any idea what would happen at Adams Key, Kopf says, they would have broken the cases to rescue the artifacts. But with blue skies overhead, who could have predicted the wind would smash down so hard early the next morning, perhaps reaching 175 miles per hour in a vertical "microburst"? Or that park employees would return to find flimsy generator and laundry sheds intact, but the Casino and a nearby ranger's residence spread all over the southern end of the key and washed into Caesar's Creek?
"What we did, we doubled up the plywood on the doors thinking of looting, not thinking of the building not being there," Kopf recalls. "Big deal. We didn't even have a building, let alone looting. All there was was all the sewer pipes, water pipes, and electric sticking out of the ground, and a lot of chimney, big pieces of chimney."
Removing a pen from his pocket, he sketches the outline of the Casino on a cardboard box. One wing of the structure housed a classroom for environmental education; the other held the exhibits. In between was a breezeway where Kopf used to sit and eat his lunch, imagining the place was his. Now only a bare white patch on the ground remains to show where the Casino stood. Disintegrated by wind, scattered by tides that flowed at least kneedeep across Adams Key, the last remnants of the Cocolobo Club had to be picked out of the defoliated mangroves.
It could have been worse.
Again sketching on the cardboard box (holding new door handles for the Elliott Key visitors' center), Kopf shows me how, at Adams Key, the wind for the most part blew against the direction of the storm surge. At Boca Chita Key the two combined forces, ripping palms and Australian pines out by the roots and obliterating a set of 1930s-vintage concrete bungalows. "No sign of 'em, no idea where they went. Any one 'em," Kopf says, his amazement at the sight still evident. At age 60 a veteran of three decades of life and storms on the Keys -- including Hurricane Donna in 1960 -- Kopf remains fascinated by Andrew. "A different thing happened there," he continues, referring to the structures on Boca Chita Key. "It got undermined. The water crossed that land with such velocity that -- when you're standing at a beach, you feel the sand eroding under your heels? That's what happened there. It washed out from under them."
Downstairs, under the elevated visitors' center, Kopf shows me a half-dollar-size black disk about two inches up on the base of the building's central pillar. Placed there by the U.S. Geological Survey, it records the high-water mark during Hurricane Andrew. That may not seem to be much of a storm surge, but the water had to travel about one-third of a mile overland from the Atlantic to get there, a substantial distance.
Following that trail into the woods at high noon, a time calculated to find the bugs asleep in the bushes, is like wandering into Jurassic Park two years after the dinosaurs have taken over. Only in this case it's the vinosaurs -- fast-creeping native and exotic vines that have thrown a green shroud over the tumbled casualties of the hurricane. About a hundred yards in, a north-south track crosses the trail. Almost swallowed by overgrowth, it offers an object lesson in the explosive recuperative powers of the tropical hammock. Bulldozed six lanes wide in 1968 by developers seeking to forestall creation of the park, this was to be Main Street for the imaginary city of Islandia, its link to Key Biscayne via an eight-mile causeway through the Ragged Keys to the north. When the park service took over Elliott Key and environs in 1968, most of the roadcut, like the developers' dreams of Islandia, was allowed to fade back into the forest. Enough still survives -- kept open by the park service -- to allow golf-cart passage, no more.
A short tromp north on Main Street (or, as the rangers call it, "Spite Highway") brings you to another east-west trail, the outbound leg of a mile-long interpretive loop. Nearby, one of a few surviving concrete interpretive signs poses an out-of-date question from the center of a still-devastated jumble of dead wood: "Can you imagine any kind of order in the bewildering, tangled, jungle-like green growth around you?" With the exception of a single surviving tree, leafing directly out from its delimbed trunk A this is how Elliott Key must have looked just after Andrew, like the shell-pounded island target of a World War II amphibious landing. Here, too, there have been invaders, ready to exploit any toehold they could seize. Air-dropped by birds that ate its orange berries, an exotic shrub called Colubrina asiatica has dug in along Spite Highway. Down along the beaches crawls Itomoae alba, a native but out-of-control variety of morning glory also known as "moonvine," throttling small trees trying to re-establish a diverse pioneer community. More familiar exotics such as papaya and pineapple have taken advantage of the destruction of the forest canopy to spring up, like a fruity fifth column, from seeds that possibly date back to the settlers who farmed the key decades ago.
One of Elliott Key's exotic invaders gives park personnel more headaches than any other. The air-mobile, deep-rooting Colubrina -- described by biology technician Diane Riggs as "actually a very pretty plant [with] green, shiny leaves" Acovers ground quickly and clings tenaciously to what it has taken, shading out any resistance. When the park launches its planned counter-Colubrina-insurgency campaign this fall, workers will have to carry out search-and-destroy missions in the tangled terrain of a blown-down hammock. The mosquitoes will take no prisoners. And the insidious shrub itself will prove a maddening adversary, its continuous berry-producing capabilities making even the act of extermination (hacking, followed by herbicide) a means of seed deployment.
Walking along the rocky Atlantic shore of Elliott Key at dusk, I come upon an artifact straight out of a surrealist's dream. Beached on its back at the high-tide mark, surrounded by foul-smelling seaweed, is a white refrigerator that suggests nothing so much as the castaway concert grand of The Piano. Half-expecting to see Holly Hunter pop out of the bushes to berate me in sign language, I open its door for a furtive peek inside. No light comes on, but otherwise it seems in working order -- less rusted than the one in my kitchen, and stocked with tossed seaweed-and-coconut salad, accented by silverfish and live snails.
A few yards away from this culinary treat, my feet crunch on broken fragments of elkhorn coral, washed in from the reef by centuries of pounding surf. Even without the added muscle of a hurricane this is what biologists would call a "high-energy environment"; it tosses around heavy kitchen appliances and pulverizes coral as a matter of course. When it really wants to exert itself, it chucks big boulders dozens of yards inland into the woods. I have this on good authority from associate research scientist Jack Meeder of Florida International University's Southeast Environmental Research Program.
Meeder and his colleague Mike Ross found the boulders ten days after Andrew, when they undertook a quick survey of the storm's damage to Elliott Key. At the time, they had just completed a preliminary writeup for a study of a mangrove site on the mainland directly across the bay from Elliott Key, a mature forest with 60-foot-tall trees, some of them perhaps 80 years old. Then the hurricane arrived, Meeder says, and "changed our whole attitude."
A tour of Meeder's now-decimated mainland mangrove site tells you his attitude change wasn't for the worse. Balanced on a downed mangrove inside a muddy chaos-zone of crushed and twisted limbs, a shock of dark hair exploding from the back of his Jamaican Red Stripe cap, he positively glories in the devastation of the hurricane. "Right after the storm, there was essentially no green at all out here," he says, his voice teetering on the edge of surfspeak. "It looked like a death scene from Hell, man, it was really incredible. You ever read the trilogy The Hobbit and all that? Going through the dead swamp to get to the castle? You know, that's what this reminded me of."
Ten yards north, the smaller and more agile Ross clambers nimbly from tree to fallen tree, easily staying ahead of us. Meeder moves comfortably over and through the broken mess; I pick my way like a particularly clumsy orangutan. Meeder and Ross know this ground well. Over the last year and a half, they've surveyed its topography to the centimeter, painstakingly dissecting a two-kilometer stretch of terrain along Biscayne Bay. All around us an instant mini-jungle of red-mangrove saplings has sprung up. A year or less old, some reach heights of six or seven feet, their bright-green leaves standing out like fresh paint against the drab gray-brown of dead and decaying wood. "After the storm there was no green," Meeder says, repeating himself for emphasis. "We had a few trees survive, and then we had this understory growing. All the big stuff dead, except one or two, and now we have all this young stuff growin' like crazy."
It's a tale that has replayed itself throughout coastal South Dade, but nowhere so dramatically as here, just north of Biscayne's mainland headquarters at Convoy Point, directly east of Homestead. Patterns of mangrove destruction vary, depending on position relative to the center of the storm and the height of the trees involved. In some places, Andrew's tides actually acted to protect mangroves. Heading north by boat from Card Sound Bridge along the back side of the Keys a few days after the hurricane, Meeder says, you would have seen the high-water mark recorded on the mangroves as a green line that ascended as you approached the storm's eye. Starting at two feet above the normal high-tide line, the green line would rise to perhaps eight feet, eventually climbing above the trees' highest branches. Mangroves and parts of mangroves submerged by the hurricane tide kept their leaves and lived; those exposed to the leaf-stripping wind died. But in the hardest-hit areas, including Meeder and Ross's study section, the storm surge itself became lethal. Twisting and tearing the trees, it enthusiastically threw its efforts into what Meeder light-heartedly refers to as "serious structural damage and instant death."
At the same time it was destroying the mangroves, however, the hurricane literally carried with it the seeds of this mainland forest's reconstruction. Mixed in with the piles of debris brought to the bay's western shore by the storm A known to those in the coastal ecology trade as the "wrack" A were thousands and thousands of six-inch-long red-mangrove propagules, or seeds. Powered up by direct sunlight, sucking nutrients from a year's worth of leaf-litter and almost a century's worth of rotting wood knocked down by the storm, a multitude of seedlings exploded from the wreckage about a year after Andrew. Today, where we are standing, they've formed a low canopy of their own. Meanwhile, the decomposition process continues all around, turning their predecessors into one more layer of the nine-foot-deep muck beneath us. "The microbes in this wood would boggle your imagination," Meeder says. "They're just eating that wood up. Some of these trees -- the reds rot real fast. You couldn't stand on a red this big around now in most cases. It'd break on you it's so rotted."
I look down at the tree on which Meeder and I are standing. Perhaps seven inches in diameter, dead and thus (to my untrained eye) unspecifiable as a red, white, or black mangrove, its solidity suddenly seems questionable. Then again, Meeder wouldn't lead me onto a bad mangrove, would he?
"You're on a red," Ross says.
"Is that a red?"
"This is white."
"I'm sorry," Meeder says as we step onto a safer perch. "I got mixed up."
The red/black/white distinction has more importance than keeping us from plunging into the muck. White and black mangroves, which prefer slightly higher ground than that occupied by the more common red variety, are able to resprout leaves when defoliated A an ability the reds lack. Where we are, perhaps five percent of the white mangroves survived, and Meeder estimates they now form 90 percent of the uppermost canopy. Where the smaller, more numerous reds are still too young to produce propagules, the whites are loaded with seeds that fall off easily when touched. "Now, what's gonna happen in the next ten years is these things are gonna compete with each other," Meeder explains, speaking of the forest as a whole. "And some of 'em are gonna survive into big trees and the other ones are gonna be shaded out by those and just die back, and we're gonna end up with a mosaic -- a highly patchy mosaic of mangrove forest coming back."
That it will come back seems unquestionable, a happy outcome that accounts at least in part for Meeder's drollery in the face of disaster. He and Ross got to watch Nature rip Meeder's Homestead house to pieces around them (Ross came up from his home in the Keys to what by rights should have been the safety of the mainland). Now they've got a chance to watch that same Nature put something back together.
Among the most dramatic photographs of Hurricane Andrew's destructive power were those that depicted the remnants of South Dade's mobile homes A hundreds of them smashed to bits. On Elliott Key, the storm got an early start in its macabre attraction to these fragile abodes. Fourteen hours before Andrew came ashore, such a trailer had been home to coral-reef ecologist James W. Porter and three other researchers from the University of Georgia. Warned by rangers to prepare for evacuation, Porter was hurriedly packing materials into the relative safety of the visitors' center when a strange and possibly quite crazy thought came to him. "I believed that the visitors' center structure would survive, and I actually toyed with the idea of staying there to try and film the storm," Porter says by phone from his new base at the Key Largo Marine Research Laboratory. "One thing that weighed against my doing that actually was not logic or safety or anything else, but the fact that it appeared the storm would hit at night, so one probably couldn't see very much. And I wasn't into sounds that much, so since the sights were going be gone, I figured the best thing to do would be to leave."
Three weeks passed before Porter was able to get back to Elliott Key. When he and his team returned, they found the visitors' center still standing -- Porter had been right about that -- but virtually everything else was decimated. Their living quarters were simply gone, blown away. What trees remained had no leaves. After four summers on the jungle island, the sudden desolation was hard to take, and Porter expected no less a catastrophe offshore, in the forests of shallow-water corals whose health was his prime concern. He had written papers about the reefs of Jamaica's northern coast, where 50- to 90-percent coral mortality followed a brush with Hurricane Allen, which pounded corals to a depth of 60 feet. He had no doubt that Biscayne's shallow reefs, only four feet deep at low tide, would have crumbled under a direct hit from Andrew. He was in for quite a surprise.
"Based upon that experience, I had expected complete and total destruction of all of the coral reefs in Biscayne National Park," Porter recalls. "So when we came back three weeks after the storm, I was utterly stunned to look at the shallow-water formations such as at Ball Buoy Reef and discover that very, very little damage had been done to those reefs in the southern end of the park."
Any speculation on his part about how Biscayne's reefs survived Andrew, Porter says, has to start by acknowledging the absurdity of their survival in light of all the data available at the time. That said, he moves quickly to two mitigating factors, the first of which -- the storm's arrival at high tide -- seems of less importance than the second: the fact that these reefs, unlike those of Jamaica's Discovery Bay, had weathered and been shaped by other hurricanes in the last 50 years.
"So what we're seeing here I think is twofold, and the first [point] is that reefs that are subject to frequent hurricane-force winds and waves are fairly well-adapted to withstand those natural disturbances," Porter says, expounding on a subject he's clearly considered carefully since recovering from his shock. "And the second thing is that the individual oceanography of a reef will either predispose it to be damaged by hurricanes or will minimize the damage. So that even within a broad spectrum of destructive capability, some reefs will survive and some will not. Reefs toward the middle and northern end of the park, which received the northeast wall of Hurricane Andrew's winds, suffered much higher mortality and destruction."
Not all the southern reefs came through as smoothly as Ball Buoy, though. Senior research associate Peggy Fong and graduate student Diego Lirman of the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences have been studying the recovery of heavily damaged Elkhorn Reef, which lies about four and a half miles east of Old Rhodes Key. A single kind of coral dominates Elkhorn; appropriately, it is Acropora palmata, the elkhorn coral, a fragile, branching, shallow-water species that looks something like an underwater tree made of stone. Its apparent frailty is deceptive. Unable to stand up to the whiplash of hurricane waves and the more massive corals that they hurl like giant bowling balls into its midst (30 percent of A. palmata colonies on Elkhorn Reef were completely shattered, and more than 90 percent suffered broken branches and other wounds), the elkhorn takes a different approach.
"One of the studies we did looked at three different adaptations that the elkhorn coral has to hurricane damage," Fong says, her blue eyes sparkling as she warms to her subject. "It heals wounds very quickly, so if you have a broken-off spot, it grows back over it. We have some photos of that. The second thing it can do to regenerate after a hurricane is that live pieces of coral -- especially A. palmata -- will settle down onto the [the sea bottom]. It'll excrete carbonate and do what we call 'cement down.' And then it'll start growing upward."
In one of Lirman's photos, an upended elkhorn branch cemented down to the bottom takes on the appearance of a fungi-encrusted stump, with new growths poking up like miniature mirror-images from what had been the base of their larger ancestor. Lirman, who arrived at the Rosenstiel School from California a few weeks before Andrew, points out that by scattering elkhorn fragments, the hurricane in fact increased the total coral cover of the reef. "[Andrew] may actually have improved it somewhat," he says. "In the long run I think it's going to be a net benefit."
Not all is sweetness and light on the reef, however. A year ago Fong and Lirman were witnesses to disturbing evidence that the corals might have suffered hidden, lingering trauma from Andrew. "Just by happenstance we happened to be out on the reef when it started bleaching," Fong says. "Bleaching," a stress-induced condition that has struck local reefs repeatedly in the last decade, occurs when coral polyps expel the single-celled symbiotic algae that help them survive. Without algae the coral turns bone-white; often it dies. "We found out from another scientist at work further south that the reef there had the same temperature and salinity regime and didn't bleach, but the hurricane-damaged one did; 25 percent of the coral cover was bleached," Fong recalls. "That was pretty significant. It was all sublethal, though; it didn't cause any death. Recovered very well. But this summer the water is heating up pretty quickly, and we're going to see how things go."
The University of Georgia's James Porter has drawn his own conclusions from the Biscayne reefs' rebound. Comparing observations made in relatively healthy Biscayne National Park with data he's obtained elsewhere in the Keys over the past eight years, Porter believes he's found evidence that salty, poor-quality Florida Bay water is responsible for the dramatic coral deaths he has recorded farther south on the Florida Reef. Drawing their water from other sources, the Biscayne reefs are shielded from Florida Bay's effects. "We believe that that is the explanation for why the reefs of Biscayne National Park are growing," Porter says. "Despite Hurricane Andrew, they're doing just fine. It is because they are removed from Florida Bay water and protected from it by nature of the oceanography and the presence of Elliott Key and Key Largo, which are the two longest keys in the Florida Keys. They protect those reefs in the north from Florida Bay water."
The irony can't escape Porter -- that the reefs he expected to be thoroughly demolished by Andrew are in fact doing better than reefs untouched by the storm. But he prefers to point out a larger irony, one arising from the surprising toughness and adaptability that South Florida's natural systems -- so long in retreat from man's intrusions, so often portrayed as enfeebled -- showed under attack by the ultimate heavyweight. That strength throws into sharp relief the collapse of man-made, urbanized South Dade. It also offers what Porter thinks is one of the most critical lessons of Hurricane Andrew. "It's important to emphasize that the natural communities of South Florida were well-adapted to withstand hurricanes," he says. "And in fact we've been back to Elliott Key this year, and you can still see signs of destruction. But it looks like a beautiful place, and unless you knew there was a hurricane, you might not be impressed with the destruction. In fact you'd be impressed with the opposite, impressed with how lush the plant communities on the island look. To my mind this is in contrast to the human communities of South Florida, which were so horribly damaged by these hurricanes. And I think again, the problem that occurred within the human communities of South Florida is that they were not built with the idea that this would be a natural and recurring phenomenon."
A natural and recurring phenomenon. Now, that's something to think about.
