CHINCHORRO REEF

The majestic Chinchorro Bank reef rises out of 1000-meter-deep waters, and is located thirty kilometers from the coast of southern Quintana Roo. Located near the Mexican border with Belize, the massive reef is many things at once: commercial fishing zone, ships' graveyard, divers' paradise, wildlife refuge, underwater garden, sand factory, haunt for migratory birds, scientific work station and fishermen's camp.

Text by Juan José Morales / Photos by Claudio Contreras

Chinchorro is the largest and oldest reef in Mexico. Formed millions of years ago; many divers consider it the most beautiful one, both for the diversity of the plant and animal life and for the fact that, unlike other reefs, Chinchorro remains pristine. Growing on a massive plateau, the reef covers approximately 800 square kilometers, less then one percent of which is above water. The rest lies just below the surface, a 46-kilometer-long by 15-kilometer-wide chain of oval-shaped coral. At its center is a calm, 4-to 5-meter-deep lagoon full of sea grass and small clumps of coral.

    The windward (eastern) flank of the reef is punished by waves and whipped up by winds that gain force as they move across the Caribbean Sea. The wrecks that litter the reef are testimony of the terrible potential of these winds. At the opposite bank, the waves are calmer and easier for ships to manage.

    Storms have worn at the reef over the years, which both erase islands and accumulate sand to form new islets or cays. Two recently formed islands make up Cayo Norte (North Cay), each stretching less than one square kilometer, and are separated by a small channel at the northeastern end of the reef. Cayo Lobos (Wolf Cay), to the south, is a victim of harsh currents and battering waves that change its appearance from one week to the next. Lobo's ancient lighthouses rest in the sea at the edge of its tiny, 0.2 square kilometer surface. If the reef were a target resting in the sea, its bulls-eye would be Cayo Centro (Central Cay), a large reef island at the heart of the lagoon. Its five square kilometers are covered with vegetation and sea birds.

UNDERWATER BEAUTIES

In shape and structure, Chinchorro resembles Pacific Ocean atolls like Bikini and Mururoa, which are circular. Their similarity was first considered a coincidence, until scientists realized that Chinchorro too, is an atoll. Like its Pacific cousins, Chinchorro evolved through a combination of tectonic processes, changes in sea level and coral growth.

    Coral is a living organism composed of colonies of polyps, tiny creatures that share a common skeleton. Chinchorro harbors 70 species of soft and hard, or rock, coral, whose skeletal structure is made of calcium carbonate. Coral grows into exotic shapes; each named for the thing it most resembles, like lettuce, candelabra and flower. Two of the most common hard corals are elkhorn (Acropora palmata) and staghorn (Acropora cervicornis), primary reef builders due to rapid growth rates and an ability to withstand heavy wave action. Within a short time, these two will have built barriers behind which the more delicate coral can grow. Next, come the strange-looking brain coral (Diploria strigosa) and the hemisphere-shaped Diploria labyrinthi forms. The latter grows slowly but grandly, reaching several meters in diameter and living for hundreds, even thousands of years.

    Chinchorro is rich in sea fans and sea feathers (gorgonians); the soft, flexible corals are so named for their similarity to those objects. They thrive in surging water and are often full of the beautiful, if tiny, flaming tongue snails.

A SYMPHONY OF COLOR

Anemones are so like flowers that it is difficult to believe they are animals. Found on Chinchorro in great numbers, anemones are related to polyps, but are larger. They are found in bright colors and have tentacles from which tube worms open plankton-trapping "umbrellas" that resemble the plumage of exotic birds.

    Sponges are also found in abundance on the reef. They come in a variety of species, at least 20 of which live in Chinchorro. The largest is the sea tub (Xestospongia muta), so named because it often grows to resemble a bathtub.

    The sea urchin most commonly seen at Chinchorro is the Diadema antillarum, which has long, dark, pointy spines. A shorter, thicker-spined species is just as prevalent, but because it prefers the underside of rocks and the nooks and crannies of hard coral, it is rarely seen. Star snakes also like to hide in rocks. They are similar to star fish but have longer appendages and are covered in spines. Other reef dwellers include various kinds of crab, shrimp, snail, conch, and worms. Many reef creatures are nocturnal and are seldom active during the day, others, if out, are cautious. Creatures that seem do not seem to have a care in the world are fish. Of the 200 species identified so far, the majority are colored tropical fish that tend to swim in schools: parrotfish, butterflyfish, angelfish, baloonfish, sergeant majors, surgeonfish, damselfish, blue angelfish, tangs, wrasse, jacknife and many others. These bits of color flit among the coral, apparently unperturbed by man or beast, certainly not by the barracuda and moray eel, both of which feed on their species.

CARRIER BIRDS

The flora of Chinchorro is surprisingly diverse. Seeds are carried to the reef by sea currents or deposited in bird droppings. The plants are not just varieties that can withstand constant wind and high salinity. They include trees native to the inland jungles of the Yucatán, like the Bursera simaruba, which can only have arrived via the intestines of the Vireo griseus, a migratory bird that feeds on the fruit of the tree on its way to Central and South America. The cays are covered with mangroves, a type of tree that flourishes in brackish or saltwater. The mangroves provide shelter and a feeding ground for many of the reefs animals, birds and fish. Yet the plants that attract the least attention are the most important: the sea grass on the sandy bottom of the lagoon, like the turtle grass and manatee grass (Syringodon filiforme). Turtle grass is slimy to the touch, and has narrow, flat, flexible leaves that look like green ribbons.

    Manatee grass is bright green or yellow-green and looks like uncooked spaghetti. These grasses fan out across the ocean floor like an aquatic prairie that feeds a host of animals: fish, mollusks, crustaceans and worms, which in turn nurture the larger grazers further up the food chain.

    The turtle and manatee grass are some of the few flowering plants that live in saltwater. The many varieties of algae that exist here have no roots and bear no flowers. What all forms of algae do have is a high concentration of calcium carbonate, which they release into the water as they decompose; it settles on the sea floor, is picked up by the tide, and eventually finds its way to the coast where it becomes the Caribbean's legendary white sand.

A SPECIES NOW EXTINCT

Reptiles and birds constitute the majority of Chinchorro's land animals. Since there is little fresh water, there are no mammals and no amphibians. Cayo Lobo is named after the now extinct monk seal (Monachus tropicalis), also called the dzulá or ts'ulá in Maya. It was the only tropical seal in the Americas and roamed the Caribbean and the Gulf of Mexico. Prized for its pelt and oil, the seal was almost hunted to extinction after the Spanish conquest (16th century). The seals avoided people, and when the islands it used as breeding grounds became inhabited, their population declined rapidly. The last sighting was after 1950, and the species has been considered extinct since 1975.

    Seagulls, pelicans and frigates are common to the reef. Called chimay in Maya, the enormous frigate bird (Fregata magnificent) is one of nature's wonders. It has the largest wingspan to body weight ratio of any bird—stretching 1.75-meters and weighing only 1.5 kilograms—and is able to stay airborne for hours. Frigates have been sighted hundreds of miles from land, though they cannot land on the water without sinking. Colonies of frigates live on the cays where, during nesting season, the males guard the young. Males have a bright red neck sack that inflates during the mating season; females have a white breast and are often airborne, since they are the primary hunters.

    The osprey (Pandion haliaetus) is another fascinating reef resident, a large raptor whose nests can be spotted in the branches of dead trees. It dives for its supper, aided by its powerful claws and beak.

    Visitors who watch the beaches of Cayo Norte and Cayo Centro at night during the summer months may catch a glimpse of sea turtles burying their eggs. Species of sea turtle known to frequent the region include the green, or white (Chelonia mydas), hawksbill (Eretmochelys imbricata) and giant loggerhead (Caretta caretta) turtle, the largest in the world.

    The reptiles most frequently seen are iguanas, lizards and crocodiles (Crocodylus moreletii); the latter now left in peace after being hunted for centuries for the sake of their hide.

SHIP'S GRAVEYARD

The Chinchorro Reef was known to sailors who dreaded it as early as the colonial period. Traveling from Cartagena, Colombia, to Spain by way of Havana, Cuba required ships to pass close to the bank. The winds and currents of the region worked against them, and many vessels went down at the reef. The remains of at least 18 ships that sank between 1600 and 1800 have been discovered.

    The reef has proved just as treacherous to modern ships. Near Cayo Centro there is a wreck called the Glenview, a British cargo ship with a 120-meter draft that went down in 1960 not far from the Ginger Scout, which preceded it four years earlier. The list of ships that have ended their days on the reef is long: the Cassel, the Far Star, the Tropic, the Huba, the San Andres, and others so torn up, only their canons and the river rocks they used for ballast are left. At one spot a line of anchors, obviously dropped one after the other in a desperate attempt to stay the ship, is all that remains.