Posts Tagged ‘mangroves’

A book is born

March 4th, 2011
Let Them Eat Shrimp

Let Them Eat Shrimp

I can’t believe that it was more than 18 months ago that I last updated this blog, saying “See you in September.” Well, that didn’t happen, did it! I was unable to raise the necessary funds to visit the mangroves of Thailand and Indonesia, so I pressed ahead with the book based on the research I had already done. Then came the global recession and a general slowdown in book publishing, and publication of my book was delayed for close to a year.

BUT HERE IT IS! Looking lovely in hardback, and available now from online booksellers such as Amazon and Fishpond. You will notice that the book has a new name—not “Last Stands,” which was my original title, but “Let Them Eat Shrimp,” which the publisher felt would make a stronger connection with American readers. And a great title it is, too, casting shrimp farming as the Marie Antoinette of seafood industries.

For more information about the book, see http://letthemeatshrimp.org/, which redirects to Island Press’s website. The publisher will be putting up reviews and announcements on that site over the coming months. There is the possibility of an author tour of the US later in the year, and I’ll post about that if and when it happens.

Thanks for being part of the journey, and I hope you enjoy the book.

Pelliciera comparison and Belize alert

July 5th, 2009

Having just learned how to put PowerPoint presentations on the blog, I am providing two such slide shows created by Candy Feller. The first concerns Pelliciera rhizophorae mangroves, and the second sounds the alarm re the impact of development on mangroves in Belize.

Wetland or wasteland?

June 28th, 2009

As arranged, Karl, Rosabel and I show up at the camp by the river at Juan Diaz at seven. High tide is heaving the flotsam of trash in slow rhythmic waves. The Bay of Panama should be called the Bay of Garbage. It floats down the rivers and the tide distributes it along the beaches and up into the mangroves. We walk through it up to our knees to get to the canoe, a stumpy dugout that looks in danger of capsizing even before we get in, let alone once we start across the channel.

Wetland or wasteland?

KENNEDY WARNE
Wetland or wasteland?


Viĵil paddles us to the opposite shore, where we set out to find the old crab collector. We follow a trail under the roosting trees of pelicans, cormorants, frigate birds and vultures. The undergrowth is so spattered with guano it looks like someone with a paint gun has run amok. The stench of ammonia is intense. Pelicans hoist themselves off the swaying branches and wing across the bay, rising and falling against the distant skyscrapers of downtown Panama.

We slosh through the mud, the mangrove breathing roots and the trash. We are at least a hundred metres from the shore now, but light bulbs, soft drink bottles and flip-flops lie in drifts amongst the trees. On a patch of higher ground I am surprised to find cactuses growing among the mangrove roots.

Pelicans, mangroves and the highrises of Panama City.

KENNEDY WARNE
Pelicans, mangroves and the highrises of Panama City.


Antonio finds a path that winds through tall canal grass—an introduced species that looks like ordinary grass on steroids, growing head-high on thick stalks—and we reach the crabber’s hut. Embers are smouldering under a cooking pot, but the crabber is nowhere to be seen. Viĵil and Antonio whistle and call, but there is no response. They conclude that he has gone off hunting.

It isn’t possible to wait for his return. So quickly does the tide fall on the Pacific coast that we would be stuck here until evening. Even on the way back to the canoe the sea has retreated by hundreds of metres, leaving a brown silt soup below the wrack line.

Viĵil, Rosabel and Karl negotiate the mangrove trash-heap.

KENNEDY WARNE
Viĵil, Rosabel and Karl negotiate the mangrove trash-heap.


And so ends my visit to the mangroves of Panama and my journey among the mangroves of the Americas. Seven weeks, six countries, dozens of communities visited, hundreds of people met. It seems appropriate to be finishing up in a mangrove forest that is both a cornucopia and a rubbish heap. Juan Diaz epitomises the mangrove problem: treasured by the few, trashed by the many.

I don’t see much hope for the rainforests of the sea until their true value gains wider recognition. I don’t mean just a price per hectare, but their intrinsic worth. Karl Kaufmann mentioned something that has stuck with me: the need for a new narrative about land use. It is no longer legitimate, he said, for us to think of land as private, discrete assets. “From the point of view of the earth, my plot of land isn’t separate from everyone else’s. We all have a stake in what’s left.” This is a big topic of discussion, one I have I only started to get my head around. Smarter minds than mine have written about the need for a transition from an environmental metaphor of infinite wilderness, inexhaustible and impervious to human desecration, to one of the “house of nature,” finite and vulnerable, which each resident shares with everyone else.

An unusual sight: cacti among the mangrove pneumatophores.

KENNEDY WARNE
An unusual sight: cacti among the mangrove pneumatophores.


As I see it, my task with Last Stands is to help establish and promote the intrinsic worth of mangroves, and to make connections between one resident in the house (eg the consumer of unsustainably farmed shrimp) and another (eg the cockle collector who relies on healthy mangrove stands). A shared sense of values surely leads to a shared desire to preserve. Or as Jacques Cousteau once put it: people protect what they love.

Beside the canal

June 27th, 2009

With the afternoon high tide lapping at our ankles, Rosabel’s husband Karl Kaufmann and I are poking around in a patch of mangroves in a suburb of Panama City called Diablo. It’s in the former Canal Zone, a corridor of land that extended five miles on either side of the Panama Canal and was controlled by the US until 1979. It’s a leafy neighbourhood of spacious weatherboard duplex houses that were characteristic of the zone—an entity that ended in 1999 when the canal passed to Panamanian control.

Panama's cash cow: the canal.

KENNEDY WARNE
Panama's cash cow: the canal.


Karl, who has lived in Panama for 30 years and works as data manager at the Smithsonian lab, tells an amusing story about the city being unhappy with the name Diablo and changing it to Altos de Jesus, “Jesus Heights.” But the residents objected, and signs with the new name kept disappearing, until eventually the name change was given up as a lost cause. (So it is now accurate to say that the Panama Canal lies between the devil and the deep blue sea.)

We’re in an area of boatyards, boatsheds and rickety wharves. Karl remembers seeing Pelliciera here in the past, and, sure enough, as soon as we start looking we spot the distinctive pointy leaves and star-shaped flowers. Here on the Pacific coast, the flowers of Pelliciera are much pinker than they are on the Atlantic. Candy Feller wonders if they are distinct species.

A fly discovers the nectar riches of an unopened Pelliciera flower in Diablo.

KENNEDY WARNE
A fly discovers the nectar riches of an unopened Pelliciera flower in Diablo.


There’s something special about finding a treasure like Pelliciera in a neglected backwater in a place called Diablo. It’s partly why I became interested in mangroves in the first place. They’re maligned, they’re marginalised, they’re considered uncharismatic. Documentary makers aren’t beating a path to the mangroves. Their eyes are on terrestrial rainforests and coral reefs. I’ve got nothing against those habitats, but they’ve become ecological celebrities. Mangroves are underdogs. I like the idea of showing what they’re made of.

I turn to see a container ship slipping past, leaving the canal. The canal is being expanded at the moment, with the predictable attendant loss of mangrove forest. Karl asks me a question: Is there anywhere I’ve been on this journey where mangroves are held in high esteem by a majority of people? I can’t think of any.

In the evening Karl and Rosabel take me to the visitor centre at Miraflores Locks, where we watch the electrified “mules”—vehicles on rails on each side of the locks—towing ships through the canal. “The next TV you buy may have spent some time on an old mangrove site,” he says. “Panama grew up on the edge of mangroves, but today’s city is turning its back on them in favour of golf courses and recreational areas.”

A five-billion-dollar expansion will give the canal two new flights of locks and allow larger ships to pass through.

KENNEDY WARNE
A five-billion-dollar expansion will give the canal two new flights of locks and allow larger ships to pass through.


The mangrove outlook isn’t all bad. Along with the recent protection of coastal land along the Bay of Panama, resolutions have been passed that attempt to put a price on mangrove loss. Where mangrove removal is deemed a “public necessity” the land is valued at $20,000/ha. If part of a commercial project the price goes up to $150,000/ha. If mangroves are removed illegally, the fine is $300,000/ha.

Karl sees a problem with this approach. “If you put a dollar value on mangroves it’s an incentive to sell. You’re taking a public asset—the goods and services that mangroves have provided for hundreds of years—and putting it up for grabs in a one-time sale. And it isn’t even the people who get reimbursed for the loss of the asset, it’s the government.”

The correct approach, Karl thinks, is that for every hectare of mangroves taken, a hectare should be replanted. That way the public good is perpetuated for future generations.

Canalside mangroves of Diablo.

KENNEDY WARNE
Canalside mangroves of Diablo.


Rosabel and her colleagues are working to develop a conservation strategy for the Bay of Panama protected area, which they hope will be incorporated into the management plan. They expect battles ahead. Nearly half a million hectares of land near the protected area is under consideration for mining, and a further 40,000 ha just offshore is subject to applications for the extraction of rock and sand. The protected area is going to need sharp legal teeth to fend off developers. It will be interesting to see how the city balances its commitments.

A city and its mangroves

June 27th, 2009

How does a city live with its mangroves? How does it accommodate growth without irreparably damaging its natural assets? Or is that an impossibility? These are questions I am trying to address while in Panama.

Panama's dilemma: burgeoning city, declining mangroves, and a mountain of trash.

KENNEDY WARNE
Panama's dilemma: burgeoning city, declining mangroves, and a mountain of trash.


Today Rosabel Miró wants to show me a new area of coastal development, at a place called Juan Diaz, on the eastern fringe of the city. To get there we drive past the crumbling rock walls of Panama Viejo, Old Panama, sacked by the pirate Henry Morgan in 1671. Then through the upscale residential area of Costa del Este, then past a sign announcing “Santa Maria Golf and Country Club” to the development site itself, where bulldozers are at work.

Rosabel has shown me a newspaper article with an aerial photograph of the site. It shows a dramatic juxtaposition of intact mangrove forest, a recent residential development and a great scar of development in progress.

The city's advance is the mangroves' retreat.

CAVU
The city's advance is the mangroves' retreat.


She is concerned about this new development because it is within an area that was declared a protected area in February of this year, and because the continued nibbling away of mangroves poses a threat to shorebirds. As director of the Panama Audubon Society, she has a vital interest in the welfare of those birds.

“The Bay of Panama is the most important stopover for migratory shorebirds in Central America,” she told me. Two million shorebirds of more than 30 species, including plovers, sandpipers and whimbrels, use the area. One reason they stop here are the huge tides on the Pacific coast—up to seven metres difference between high and low. When the tide goes out it exposes up to 70 km of mudflat—a huge open-air buffet.

Two million shorebirds use the mudflats of the Bay of Panama as a migratory stopover.

KARL KAUFMANN
Two million shorebirds use the mudflats of the Bay of Panama as a migratory stopover.


Mangroves are important to shorebird ecology not just because of biological interactions between mudflat and mangrove forest but also as safe roosting areas at high tide and a security buffer between the birds and urban areas inland.

After looking at the site we drive to the end of the road, where a cluster of ramshackle huts stands on a scrap of land between the mangroves and a sheetmetal works that is turning out sections of tailrace tunnel for a hydroelectric project.

We brush past banana palms and papaya trees and introduce ourselves to Antonio, Magdalena, Lisbeth and Viĵil. They’ve drifted together, along with a few others, by happenstance and word of mouth. They have fashioned a simple, if not entirely idyllic, existence on the shores of the bay, drawing from land and sea for their sustenance. The fact that they wake in the morning to the sound of arc welders and angle grinders is a small price to pay for a life close to nature.

Magdalena with pumpkin.

KENNEDY WARNE
Magdalena with pumpkin.


We swing in hammocks in the shade of an almond tree and they talk about their life here. A crocodile tried to eat one of their dogs so they shot it and dined on crocodile for a good while after that. They grow vegetables in what looks like pretty fertile soil. Magdalena shows off a huge pumpkin which will be used as crab bait in the ingenious spring-door traps they set out at low tide.

Rosabel is enjoying herself, singing to a parakeet that is perched on her finger. She grew up with parakeets—“they were all called Juanito or Juanita”—and she and the neighbouring kids used to go adventuring in the mangroves next door to the house. So she has a warm feeling for this little band of outcasts living their Swiss Family Robinson life. (When I offer the bird my finger as a perch, it pecks me with a grip that could crack a macadamia.)

Rosabel Miró with friend in Juan Diaz.

KENNEDY WARNE
Rosabel Miró with friend in Juan Diaz.


Like all subsistence communities, they know the bounty that each season brings. November is when the iguanas come, for instance—“cooking time,” Viĵil says with a grin. Antonio walks a few steps into the mangroves and uses a table knife to show how he digs up shellfish from around the trunks of the trees. It isn’t the mangrove cockle, but a much smaller bivalve that lives in sandy conditions. It looks like you would need a lot of them for a meal.

Mounds of empty soft drink and beer cans are scattered through the camp. When the scrap metal merchant comes they’ll get a few dollars for the aluminium. Lisbeth, an older woman, says she collects parakeet chicks in the mangroves during the breeding season, raises them to fledging size and sells them in the city, three dollars each.

Antonio with mangrove molluscs.

KENNEDY WARNE
Antonio with mangrove molluscs.


They tell us there’s an old crab collector living alone, deep in the mangroves on other side of the river, and offer to take us to meet him at high tide the next morning. It’s a deal, we say. We’ll show up with breakfast and they’ll paddle us across the river to meet him.

Before we leave I ask if anyone from the new development has visited them, perhaps to tell them they’ll have to leave. They say no, and clearly hope that it stays that way. I hope for their sakes it does.

Ecologist at large

June 23rd, 2009

When I was at university, involved in the cutting-edge discipline of sponge classification, I regarded ecology as “soft” science, suited to those who lacked the intellectual molars to chew more demanding meat. Ecologists, I liked to think, were the ones Mark Twain had in mind when he wrote, “There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.”

Candy Feller and team exploring a new river.

KENNEDY WARNE
Candy Feller and team exploring a new river.


Now I think differently. Ecology is about getting the big picture. And today, with the extinction rate in overdrive and ecosystems in crisis, how sorely humankind needs that perspective. Candy Feller’s CV calls her an insect ecologist, but this really means she’s interested in everything that has to do with an insect’s world of interactions, which is a wide world indeed. Tracking those interactions may entail analysing the sugar content of flower nectar or making aerial surveys of mangrove deforestation as much as it involves slicing open twigs to see what’s living inside.

Candy is part of an ecological subdiscipline called biocomplexity, the study of the mechanisms—physical, chemical, biological—that determine ecosystem structure and function. She came to mangrove ecology in an unusual way. She was a scientific illustrator, and was assigned to draw the underwater component of a mangrove ecosystem. Actually to draw under water, using waterproof materials and a scuba tank.

Pelliciera reflections.

KENNEDY WARNE
Pelliciera reflections.


She found she liked mangroves. They reminded her of the rhododendron forests of her youth—the feeling of being enclosed and embraced by nature. These days Candy lives in Maryland, but at heart she’s a Carolina gal. I asked her what her favourite southern comfort food was. “Squirrel,” she said, without missing a beat. When she was little she and her brothers used to go out and shoot squirrels for breakfast. It was pretty much a no-brainer to find out she liked bluegrass music as much as I do. We swapped stories—I’d backed Emmylou Harris on a New Zealand TV show; she’d met Gid Tanner of the legendary Skillet Lickers. Then she opened up the iTunes playlist on her laptop and we spent an hour getting high and lonesome on four-part harmony.
Candy and Anne Chamberlain team up to trap tree crabs lurking in liverworts.

KENNEDY WARNE
Candy and Anne Chamberlain team up to trap tree crabs lurking in liverworts.


When she retires she says she’s going to work on a plant called Jack-in-the-pulpit, which was found recently to be pollinated by thrips. She finds that an interesting interaction—thrips are normally thought of as pests, not beneficial pollinators. “I don’t want to publish, just to know,” she says. “I like the idea of pushing my walking frame into the garden and studying wildflowers.”

Watching Candy in the field, I’m pretty sure the walking frame is a long way in the future. By midday I’m wilting in the heat, with Noel Coward’s lyrics about mad dogs and Englishmen running through my head, but Candy, mud-spattered and sweating, presses ahead with the work. She doesn’t miss much, either. Today she found a fish I had been hoping to see: the mangrove killifish, or Rivulus. It was swimming in a shallow puddle in the Pelliciera forest, darting down fiddler crab burrows when it was disturbed.

We bought the sweetest pineapples I've ever tasted from these paddlers passing our research site.

KENNEDY WARNE
We bought the sweetest pineapples I've ever tasted from these paddlers passing our research site.


Rivulus is the only known vertebrate capable of breeding without a mate. It can develop male and female sex organs and fertilise its own eggs. What’s more, it can breathe air through its skin, like a frog, and one specimen spent 66 consecutive days out of water, living in a hole in a tree. The fish’s ability to survive out of water comes in handy for Rivulus researchers, Candy said—they swap live specimens through the post.

When the field work was over for the day we explored a new river system. We passed groves of Pelliciera where the buttress roots and their reflections produced rows of diamonds at the waterline. Candy stood in the bow of the boat, surveying the forest, enthusing about the epiphytic orchids, wondering out loud why the Pelliciera on this coast seem to reach a certain height and then stop growing. The birders in the group had eyes only for trogons, toucans and other avian exotica, but I suspected that Candy’s mind was on the mangroves, pondering how they fit into the complex ecological pattern she is helping define.

When the collecting finishes, the analysing begins.

KENNEDY WARNE
When the collecting finishes, the analysing begins.


I came across a statement from the late great US writer John Updike. His goal as a writer, he said, was “to give the mundane its beautiful due.” It seems to me that this is what Candy Feller is doing for mangroves, and I admire her for it.

Among the Pelliciera

June 21st, 2009

Here are a few more glimpses of the magic forest. (Click on photograph to start slide sequence.)

Bromeliad on a Pelliciera trunk.

KENNEDY WARNE
Bromeliad on a Pelliciera trunk.

Forest of flowers

June 21st, 2009

We’re off again, as Candy Feller says, “like a herd of turtles.”

Emily Dangremond (right) with Pelliciera blooms. Anne Chamberlain looks on.

KENNEDY WARNE
Emily Dangremond (right) with Pelliciera blooms. Anne Chamberlain looks on.


With us today are a couple of Smithsonian communications people, filming a documentary piece on Candy, and David Luther, a bird expert who works on the conservation of endangered species at the University of Maryland. A paper of David’s on vertebrates which rely on mangroves is about to be published in the journal Bioscience. This is good news for me, because I was hoping to find a list of mangrove-dependent creatures, and David has produced that very list—for vertebrates, at least. David says that almost half of these mangrove endemics—48 birds, 14 reptiles, 1 amphibian and 6 mammals—are endangered, many of them critically so.

One of his mangrove species is chattering in the branches as we wheelbarrow our gear to the boat: the mangrove yellow warbler, a canary-sized bird with canary-coloured plumage. The male has a rusty red head, as if it had been dipped in paprika.

Village in Peninsula Valiente.

KENNEDY WARNE
Village in Peninsula Valiente.


We weave our way through the Bocas archipelago and cross the bay to the Peninsula Valiente. The sea is silky calm and dotted with the canoes of the Ngöbe Buglé people native to this area. They are fishing, diving or just commuting; rivers and sea are the only roads in this area.

We stop at a village which looks like a film set: rough timber buildings on stilts at the water´s edge, blue smoke drifting through almond trees, jungle rising thickly behind. Half an hour further on and we come to Candy’s site: a forest which includes the mangrove species known as Pelliciera rhizophorae.

Candy Feller takes nectar from a Pelliciera flower.

KENNEDY WARNE
Candy Feller takes nectar from a Pelliciera flower.


Candy has a special affection for Pelliciera, which has one of the most restricted distributions of any mangrove. It occurs on the Pacific coast of Latin America from Costa Rica to northern Ecuador, and in just a few spots on the Caribbean coast. The trees have elegant fluted buttresses, straightish trunks and long spindle-shaped leaves. But their flowers are what set them apart. Almost all mangroves have small, unspectacular flowers—except Pelliciera, which breaks ranks by producing flamboyant, star-shaped, nectar-filled blooms. The nectar attracts hummingbirds (believed to be the main pollinator) as well as many insects. We even find tree crabs taking a dram. Pelliciera blooms year-round, but when flowering is at its peak the forest is alive with the whirring wingbeats and squeaking calls of hummingbirds. “Imagine being strafed by hummingbirds,” Candy says.

On a previous trip Candy discovered something unusual: when she shone a UV light on the flowers the nectar fluoresced. Today she wants to take nectar samples and have them analysed in a lab that specialises in fluorescence. This turns out to be too easy. The flowers produce so much nectar that she can fill a glass capillary tube in seconds—if, that is, she beats me to it. I’ve been in a sugar desert lately, and am making up for it by licking Pelliciera nectar (it has a delicate caramel flavour).

The fabulous blue morpho, with the fabulous blue hidden inside folded wings.

KENNEDY WARNE
The fabulous blue morpho, with the fabulous blue hidden inside folded wings.


I walk through the forest, scouting for flowers and for the peacock flash of blue morpho butterflies, whose seemingly random fluttering always seems to be out of camera range. For a while, the best I can achieve photographically is a morpho at rest on a mangrove leaf, when the heavenly blue is hidden, and all you see are an eye-patterned grey and black. Then I find a butterfly trapped in a golden orb spider’s web, with the spider feeding on its dead body. It seems unsporting to photograph the iconic creature’s demise, but it could be my only chance to record the wing colour, so I shoot a few frames. “Frames”—the old film terminology lingers. “Files” doesn’t have the same magic.
Blue morpho, golden orb.

KENNEDY WARNE
Blue morpho, golden orb.


We eat lunch of boiled eggs, tomatoes and bread, and are treated to the sight of a basilisk, or “Jesus Christ lizard” running across the river and up a mangrove tree. “Basilisk,” I learn, comes from the Greek for “little king,” a name bestowed by none other than Carl Linnaeus, father of taxonomy.

Candy, Emily and Anne follow a similar collecting pattern as yesterday, gathering seedlings, twigs and flowers, collecting crabs and, on this occasion, measuring the salinity of the peaty mud in which the trees are growing. I help with the fiddler crabs, whose large claw has an off-puttingly wide set of pincers at the tip. I find that their posture is worse than their pinch, and manage to collect several without being nipped.

Young basilisk, or Jesus Christ lizard.

KENNEDY WARNE
Young basilisk, or Jesus Christ lizard.


We arrive back at the lab at sunset, and though it’s been a long, hot day Candy can’t resist putting in a couple of hours in the lab, slicing into the twigs and seedlings with a knife to see what’s living inside.

In front of the main building two bat researchers have set up a mist net and are catching bats at a rate of one every couple of minutes. Just as in nature, institutions like the Smithsonian have their diurnal and nocturnal residents. We mangrovistas are winding down, thinking of gin and tonics and what’s for dinner, while the bat brigade is gearing up for a night of excitement. The main researcher thinks he may have captured a new species.

Night belongs to the bats . . . and their captors.

KENNEDY WARNE
Night belongs to the bats . . . and their captors.


I take a torch down to the boat ramp and spotlight the mangroves, watching tree crabs chomping leaves and flowers. Howler monkeys are making a racket in the jungle beyond the lab, while poison dart frogs keep up a constant chirruping. It’s a great life, and tomorrow I get to do it all over again!

The nutrient economy

June 20th, 2009

It takes an hour by speedboat from Isla Colón, where the Smithsonian research station is located, to reach Isla Popa, where Candy Feller has one of her experimental sites.

Anne Chamberlain (left) and Emily Dangremont tickle the mangrove roots for crabs on Isla Popa.

KENNEDY WARNE
Anne Chamberlain (left) and Emily Dangremont tickle the mangrove roots for crabs on Isla Popa.


Candy’s main project in Bocas is to look at how nutrients affect mangrove growth. “Nutrients are the currency of food webs,” she says. She studies how that currency moves through a mangrove ecosystem in the same way that economists study how money moves through an economy. The three major elements she’s interested in (the dollars and cents) are carbon, nitrogen and phosphorus. She compares the ratios of each element in the mangrove trees in her study plots, and also in the herbivores that eat mangroves. Those consumers include everything from tree-climbing crabs to twig-boring miners. Candy has found more than 100 species which feed on mangrove twigs alone.

Some of the associations are intricate and fascinating. For example, the exit hole of one borer may be the entrance way of the next species in the chain. One of Candy’s favourites is a nemertine worm which takes up residence in an empty beetle gallery. The worm traps its prey by everting its insides. Charming!

Candy Feller in the dwarf mangrove forest.

KENNEDY WARNE
Candy Feller in the dwarf mangrove forest.


So thoroughly do creatures use the mangrove habitat that a seedling with its leaves in the air and its roots in the water will have terrestrial borers burrowing down from the top and marine borers burrowing up from the bottom.

As well as measuring the nutrients in an undisturbed system, Candy has added nutrients in the form of fertilisers to see how the mangroves and their associated flora and fauna respond. This is an important line of research because nutrient over-enrichment is a growing problem for marine ecosystems around the world. As fertilisers run off the land and into the sea, the delicate nutrient balance of mangrove and other communities (seagrass beds, coral reefs) can be thrown into disarray.

As we step off the boat there’s a surprise: a golden orb web spider has spun a metre-diameter web at head height just to one side of our access point. I hope I don’t forget its location. The spider is close to 15 cm from leg tip to leg tip, and I don’t fancy the thought of it falling down the back of my shirt. (The spider gets its name from the fact that the silk of its web is a golden colour, not white.)

Golden orb web spider near the boat.

KENNEDY WARNE
Golden orb web spider near the boat.


At Isla Popa there is a marked difference in height between the mangroves on the shore and those inland. The shore mangroves are five or six metres tall, while those inland are a bonsai forest of dwarf trees less than a metre high. Candy has found that the shore mangroves are limited by nitrogen while the dwarf mangroves are limited by phosphorus. Adding phosphorus to the dwarf trees results in dramatic growth increases, but adding nitrogen to the shore trees has much less impact.

I head into the dwarf forest with Candy while Emily Dangremont, a graduate student from Berkeley, and Anne Chamberlain, one of Candy’s associates at the Smithsonian, work on the shoreline mangroves. Our tasks include counting seedlings (living and dead) and collecting leaves, seedlings, winkles and two sizes of crab from around the fertilised trees. These will all be physically and chemically analysed back at the lab.

Leaf scars provide an estimate of the age of the dwarf mangroves—as much as 300 years old.

KENNEDY WARNE
Leaf scars provide an estimate of the age of the dwarf mangroves—as much as 300 years old.


The dwarf mangroves (which Candy refers to affectionately as “Charlie Brown trees”) are a revelation. Candy points to the leaf scars on the branches. Each time a leaf falls, a permanent record of its existence is left on the branch. Between two and three leaves fall off per year, so the number of leaf scars gives an estimate of the age of the tree. (You can’t use the normal method of counting rings because mangroves don’t lay down rings annually, but on a more irregular basis.) Though these dwarf trees are smaller than a metre in height, it turns out they are several hundred years old. They grow in a layer of peat that is close to two metres thick, which has formed from the fine roots of generation upon generation of mangroves.

In Bimini, similar dwarf mangrove forests were denigrated as “stunted mangroves” by the Bimini Bay Resort development company, which justified its plan to destroy such stands on the grounds that they were biological rejects—losers in the game of life. Seeing these ancient forests in Bocas, collecting the crabs that nestled in their leaf bases and the molluscs that clung to their branches, underscored the crassness of the developer’s rhetoric. Who can say how much life owes its existence to these trees? And who has the right to deny it?

Further inland still, where the mangroves mudflats meet the terrestrial soils of the jungle, the mangroves are much higher—10 metres or more—and festooned with epiphytes. Bromeliads, orchids and arum lilies perch and twine on trunks that are felted with moss, liverwort and filmy fern. Candy thinks of the epiphytic community as a separate freshwater ecosystem suspended over the saltwater mangrove one. It is sustained by the high humidity and rainfall of Panama. (Bocas receives up to five metres of rainfall annually, spread throughout the year—but, luckily for us, not on the days we are in the field.) The epiphytes provide yet another level of complexity in an already complex system.

Epiphytes on the mangroves are a feature of Panama.

KENNEDY WARNE
Epiphytes on the mangroves are a feature of Panama.


I walk back to the shore mangroves to help Emily and Anne catch crabs. The most effective method is to “tickle” the algae-covered roots at the water line with your fingers, hoping to flush the crabs from their hiding places and cause them to climb up the tree. If you’re quick enough, you can grab the crab before it realises its danger and jumps into the water.

Aratus, the tree-climbing crab we’re going after, has an infuriating knack of staying on the opposite side of the branch to the side its pursuer is on. This isn’t such a problem if the branch is narrow, but on a thick trunk I sometimes circled round and round (with occasional feints in the opposite direction) and only glimpsed bits of disappearing leg or pincer as the crab kept deftly out of sight.

It’s great to be in the company of scientists again, sharing a quest for knowledge. Je ne regrette rien, but at times like this the scientific career path I set aside for journalism has the allure of the road not taken.

Battling for Bimini

June 16th, 2009

Young lemon sharks use mangroves as a nursery area.

MATTHEW POTENSKI
Young lemon sharks use mangroves as a nursery area.

Photographer Matt Potenski from the Bimini shark lab and I are snorkeling among the mangrove roots in the Duckpond, an embayment a short boat ride from the lab. The prop roots of red mangroves (the primary species here) form cloisters and grottoes through which fish glide like birds through a woodland. In a place like this you can understand how effective mangroves are as a nursery area. Fish simply melt into the forest.

The roots themselves are thickly encrusted with brick red fire sponge and other filter-feeders. Clusters of mangrove oyster grow at low-tide level. Many roots are not attached to the seabed, and bob and sway gently in the current, as if the mangroves were dangling their toes in the tide.

On the seagrass beds beside the mangroves are hundreds of upside-down jellyfish of the genus Cassiopea—a type of jellyfish which appears to wish it were a sea anemone, because it lies on its “back” (the bell) with its frilly tentacles pointing upwards.

The red mangrove's labyrinth of roots makes it an ideal fish refuge.

MATTHEW POTENSKI
The red mangrove's labyrinth of roots makes it an ideal fish refuge.


In some areas the seabed has been turned into volcanoes of sand, each about the diameter of a football. These mini-Vesuviuses are the excavations of a tubeworm which burrows deep into the substrate. The lab manager told me that if you’re really quick with a shovel you can dig up the worm, but usually it retreats to the bottom of its tunnel quicker than the shovel can dig. I figure I don’t need to see a worm badly enough to destroy its home.

Clearly, though, another shovel operator doesn’t share this sentiment. In the middle of the Duckpond a digger and a front-end loader are hard at work building a causeway across the water. They are about two-thirds of the way across. Matt is flabbergasted. Despite the fact that Bimini has been a battleground between developers and conservationists for years, the impression I’ve been getting from Sharklab staff is that progress is being made. At the beginning of this year a marine reserve was declared on the eastern side of the island, which will safeguard a large area of mangroves from a developer’s dreams. Now, almost within earshot of the lab, someone is playing fast and loose with heavy machinery.

Reclamation in the Duckpond threatens mangroves and seagrass with changes in hydrology and smothering by sediment.

MATTHEW POTENSKI
Reclamation in the Duckpond threatens mangroves and seagrass with changes in hydrology and smothering by sediment.


The outgoing tide is picking up speed and carrying a plume of sediment from the earthworks out into the lagoon. Where we were following fish through the mangrove labyrinth 30 minutes earlier, now we can’t see a thing.

In the afternoon we take a boat trip through mangrove areas in North Bimini. (Bimini has two halves, North and South. The town and the largest resort are on North Bimini; the lab is on South Bimini.) Some of these mangroves were slated for a golf course for the Bimini Bay Resort, an upscale behemoth that in its original incarnation would have brought 6000 visitors to an island with a population of 1600. The establishment of the marine reserve may have taken the golf course out of the equation, but most of the mangroves we’re passing do not enjoy reserve protection, so are still “in play” as far as development options are concerned.

Grant Johnson among the mangroves of North Bimini.

KENNEDY WARNE
Grant Johnson among the mangroves of North Bimini.


We pass a smart launch on the outer coast, but mostly we are alone in the mangrove channels. From the bow of the skiff I see barracuda and spotted rays, jacks and conch, the shellfish which is a Bimini delicacy, and whose empty shells are a universal landscape feature. A green turtle speeds away from the boat, launching itself out of the water with a splash before diving into the shadows.

At dusk we idle past the manmade islands and marinas of Bimini Bay Resort. On board is a former Sharklab manager, Grant Johnson, who was in the front line of protest against the resort earlier in the decade. For him, it was the scale and inappropriateness of the project as much as its destructive impact on habitat that was offensive. “I found it borderline racist that the developer wanted to turn Bimini in Florida’s playground,” he says. “This is somebody’s home we’re talking about, not a desert island. The attitude was if the land’s not high enough, make it higher, it there’s water where land should be, reclaim it, if there’s land where water should be, dredge it.”

Bimini Bay Resort, Bimini's elephant in the room.

KENNEDY WARNE
Bimini Bay Resort, Bimini's elephant in the room.


We pass a dyke meant to confine sediment from an area of current construction. The high tide is lapping over the top. Grant shakes his head, as if to say “Can’t these guys do anything right?” Bimini is far from the Bahamas’ central government in Nassau, and there’s still a frontier flavour to the place—the very spirit that attracted Hemingway in the 1930s. Grant would like that frontier to be a nature one—see the sharks, swim with the dolphins, kayak through the unspoiled mangroves. If you’re lucky, spot a Bimini boa or a sawfish.

I notice that he has the word “Hope” tattooed on his arm. That’s the operative word for the mangrove-lovers of Bimini.