Her mission must wait until nightfall. The conditions are perfect its quiet and pitch black. But she has chosen this beach for another reason. Its the very beach where she was born. In one of natures great feats of navigation, she has traveled hundreds of miles to cuba for a single hour of work. She creates a cavity deep enough to protect her fragile cargo from the elements. Finally, she is ready. For about 20 minutes she is in a nearecstatic state. Releasing up to 200 eggs into the sand. When shes finished, she buries her precious payload. And drags herself back out to sea. She leaves her hatchlings with a oneinathousand chance of survival. And she has no idea what her beach has become. Cuba may be offlimits for americans, but for the rest of the world, the secret is out. In 1991, when the collapse of the soviet union nearly bankrupted the country, the regime opened its pristine beaches to europeans, canadians, south americans. For decades, a financial embargo by the United States has spared many turtle Nesting Beaches from a fullscale tourist onslaught. But its just a matter of time before the embargo is lifted. And then how will cubas sea turtles fare . Bretos sea turtles are very very susceptible to development. Its probably the number one threat. Theyre so dependent on beaches, clean beaches, beaches free of pollution, free of lighting. And once the pressure to develop these very pristine beaches picks up, thats going to come at the expense of some very, very healthy sea turtle nesting habitat. Narrator even on cayo largo the beaches are beginning to show the effects of tourism, and pollution is just one of the dangers the turtles face. In cuba, sea turtle eggs are a delicacy. Enterprising cubans hunt for nests and dig up the eggs to sell on the black market. Fortunately for the turtles of cayo largo, Gonzalo Nodarse and Felix Moncada have Something Else in mind. [ man speaking spanish ] interpreter sea turtles are a charismatic species. You get the feeling that the more we know about them, the less we understand them. Like, how they are born on one beach, and later they come back to the same beach to reproduce. How do they do it . Narrator felix and gonzalo are cubas top sea turtle biologists, and theyre monitoring cayo largos beaches during nesting season. The steady advance of pollution and development is pushing turtles to build their nests in increasingly dangerous areas. [ speaking spanish ] interpreter you can see that the waves come all the way up to here. This is a nest that is potentially threatened. If the sea reaches the nest, the saltwater will penetrate the embryos and theyll die. Narrator gonzalo and felix attempt to rescue the eggs from their hazardous site, and call in their local colleague, leonardo valido who runs a small hatchery on the island. The eggs are transported in the same orientation theyre found in the nest. The smell of the sand from their Nesting Beach will permeate the soft eggs, imprinting on the turtles. In the future, the females that survive to adulthood will follow the scent to this exact spot. At the hatchery, leonardo raises a few turtles from each season until theyre over a year old and big enough to tag for migration studies. He may never leave cuba himself, but he has devoted his life to these little Global Travelers that he sends off to see the world each summer. [ valido speaking spanish ] interpreter ive been here in cayo largo for about 19 years, in one way or another doing this kind of work. I love it. I love everything that has to do with nature, especially the turtles theyre like my symbol. [ counting in spanish ] narrator the temperature of the eggs will determine the sex of the hatchlings, so the team is careful to mimic the exact dimensions of a natural nest. As the threats to turtles have grown so has the scale of leonardos operation. Now, in a single season, hell hatch as many as 15,000 baby turtles. He has made it his personal responsibility to ensure that one of the seas most essential creatures doesnt disappear. Interpreter this work requires a lot of energy. Because its not something thats going to make you financially comfortable, you must be a person that first, before everything, does it with heart. If you are waiting for other benefits. There will be no positive result in the end. Narrator in 45 days the buried hatchlings will emerge from the sand. For now, leonardo must remain in cuba, but his newborn turtles will begin their journey into a vast, mysterious world. [ bell ringing ] man cuba holds some of the greatest mysteries of the caribbean. Its so uniquely situated right at the confluence of the gulf, the caribbean and the atlantic ocean. And because of the political situation over time, and the Economic Situation in cuba, a lot Less Research has been done here and a lot less is known about this ecosystem. Narrator in a land offlimits to americans for over half a century, David Guggenheim is a rarity one of the few scientists from the United States to gain access to this secretive island. Through a partnership with the university of havana, david has worked in cuba for nearly ten years. On a course due northwest of the island, he is heading into a virtual Demilitarized Zone where cuba shares its waters with its capitalist neighbors. To the north are the busy ports of the United States. 90 miles to the west a steady stream of cruise ships pours into cancun. But here, where soviet gunboats once policed the marine border cubas waters are strikingly free of traffic. On the surface. Below the waves, powerful currents form a marine superhighway, where convoys of whale sharks patrol the coastline. [ dolphins squeal and click ] schools of dolphin and grouper follow the steady stream of nutrients gathering to spawn and feed. For years, davids focus has been on the foundation of this marine world clusters of tiny creatures that are under attack across the globe coral reefs. In parts of the caribbean, more than twothirds of the corals have died. Guggenheim coral reefs are considered to be the rainforests of the sea. And roughly 25 of the worlds corals have died in the last 25 to 50 years. And the estimates for the future are that half of the worlds corals will be gone within another 20 to 25 years. Narrator these undersea cities are besieged by a barrage of forces pollution, rising ocean temperatures, overfishing, and algae. But for ten years, david has been documenting an extraordinary phenomenon cubas corals are fighting back. Guggenheim corals are animals. Some of them look like plants. And here we have corals which have been wiped out, but we also have these young corals coming right back again. And that is very very significant to see. Narrator today, david is heading to an unexplored reef. For months he has been waiting for permits to visit the site, and finally his request has been granted. Guggenheim working here is incredibly difficult and often frustrating. This expedition requires signatures from 15 different ministries, including the army because the north coast is considered very sensitive. Narrator this site, so close to the cuban coast, has never been studied by scientists. Just 90 miles south of the diseased reefs of florida, will these corals be as unhealthy as their northern neighbors . Guggenheim so much of this coast is completely unexplored. Thats the point of our research. A lot it is just dropping yourself in the water and documenting what youre seeing. So, honestly, i dont know what were going to see. Narrator Great Gardens of healthy brain corals spread out across the sea floor. Vibrant sea fans and tube sponges show few signs of the coral dieoff plaguing the rest of the planet. Guggenheim it really is a profoundly emotional experience. You get in the water and it is like turning back time 50 years to what coral reefs looked like before human beings started messing with the way these ecosystems work. Narrator david believes cubas defiantly resilient corals are tied directly to the history of the island, perhaps as far back as the collapse of the soviet union when fertilizers were no longer available. Guggenheim essentially, cuba was forced to implement organic farming practices. And without all of those nutrients flowing into the water its very possible that that had the effect of lessening the impacts on coral reefs less fertilizer, less algae growth. Narrator then david spots an old friend, a species he hasnt seen in years. A spectacular stand of acropora palmata. Elkhorn coral. These breathtaking colonies of creatures are the most important reefbuilders in the caribbean. But theyre also one of the most sensitive. Nearly 95 of the worlds elkhorn has been destroyed by pollution and disease. Here in cubas waters, these could be some of the last of their kind on the planet. Guggenheim why are cubas corals so healthy . We dont know the answer. But theres a mystery we can unlock here that could provide lessons for us to conserve corals in many other places including our backyard 90 miles north of here. Narrator cuba is the giant of the caribbean. With nearly half of the regions landmass the sprawling island was forged using nearly every trick in natures book. [ thunderclap ] wet, tropical forests meet pinecloaked mountains. And sultry wetlands give way to dry desert coasts. But despite the islands impressive grandeur, much of cubas natural splendor plays out on a decidedly smaller stage. Cuba is home to the worlds smallest bat one of the smallest owls and the smallest bird of all a hummingbird that weighs less than a penny. The bee hummingbird is a miracle of evolution, a descendant of the dinosaurs barely two inches tall. From their treetop lookouts, they perform acrobatic aerial displays, scouting for the best blossoms to satisfy their outsized appetites. In a single day, theyll eat half their bodyweight in nectar and insects. The birds size does have its disadvantages. When competing for food, its bigger neighbor, the cuban emerald, insists on first pick. One of the tiniest of cubas creatures lives not in the trees but on the forest floor a frog barely half the size of its own name. Eleutherodactylus iberia the smallest frog in the northern hemisphere. Life among the leaf litter is full of constant danger and this bitesize frog knows he can be a tempting treat for hungry neighbors. But not today. Making their way down from their treetop shelters, some of the forests gaudiest creatures are also on the hunt. These are cubas famous painted snails the polymita. With eyes perched on long stalks the polymita seek out water and lichen on the leaves of ferns and other plants. Today, Something Else has caught this snails eye. An attractive mate. Like most snails polymita are hermaphrodites both male and female which means anyone is a possible partner. The affair begins with a mysterious dance as the couple slowly circles one another. But when theyre ready to make their move its anything but gentle. The snails extend a piercing weapon known as a love dart. They puncture one another in the socalled sensitive zone, until they successfully exchange sperm. Eventually, both snails will go on to lay fertilized eggs. For now, these two are content to linger in the moment. They should enjoy it while they can mating partners are becoming harder and harder to find. The polymitas elegant armor is no defense for their latest threat. Poachers hunt them to sell as shell necklaces and trinkets and the snails are now endangered. When the u. S. Embargo lifts, a sudden influx of curiosityseeking tourists could deal the final blow. Bretos the Tourism Impact has really been minimal in cuba, but thats going to change because when you do have more tourists to cuba theres going to be a much bigger demand for these sorts of artisanal products. Its all determined by the market now. When you go from two million tourists a year to four to six to eight, everything will change. Narrator in cuba, the pace of life has changed little in decades. A small population on a large island lives in a deep association with the land. In the islands far west the redsoiled valleys of vinales are Fertile Ground for the countrys most famous export. The farmers of vinales live as they have for centuries making the most of what the land affords them. Others are tied to the land in even more remarkable ways. One woman has discovered that this Sleepy Valley offers more than just fertile soil. It provides her with answers to some of the most complex questions in science today answers hidden in the cousins of cubas painted snails. Interpreter cuba is known as the paradise of snails. Many live here in this area and nowhere else. They have fascinated me since i was a student. And i like them because of their lifestyle so free, so relaxed, so interesting. Narrator in one of the most remote regions in cuba biologist Emma Palacios lemagne is cracking the mysteries of evolution. Cuba doesnt provide emma with much money for her research and cant supply her with expensive equipment. But what cuba does give her is one of the most extraordinary laboratories on earth. Instead of test tubes, emma uses mammoth limestone karsts called mogotes. Centuries of erosion have carved them into towering island worlds a virtual galapagos, where, like darwins finches emmas snails evolve in extreme isolation. The snails on these separated hills never venture more than 60 feet from home, making this the ideal place for emma to discover how their shapes, colors and behaviors are dictated by the land. Interpreter each slope on these mogotes has its own species, and different variations of snails which all belong to the same species. On each slope, they are different from the next, because of the conditions in the habitat, humidity feeding conditions or wind resistance. You can see the diversity of forms in such a small area. Narrator the strange landscape has led to some stranger adaptations. Like one of emmas least favorite subjects, the homely bistec de mogote the pancake slug. This bizarre creature has traded its shell for a different defense. Its perfectly camouflaged to disappear into its limestone hideout. But hiding may not be enough. Emmas snails are losing habitat to expanding tobacco farms and many are hunted for muchneeded protein. She runs a small Breeding Center to ensure her precious subjects dont disappear for good. Interpreter today, with how the world is and with all the problems that there are what interests me most is conservation. And this little thing we do with this little species of snails contributes. Narrator in a land where money is scarce and travel nearly impossible conservationists have turned inward and found all the riches of the Natural World on one remarkable island. Bretos a cuban biologist doesnt make more than 25 a month. Thats just amazing to think about. Theres so much passion for what they do down there. And that definitely has a positive impact on the environment. Narrator the streets of havana are lined with reminders of the islands colonial history. But just a hundred miles to the south civilization gives way to cubas primeval past. Over a million acres of unspoiled caribbean wetlands Cienaga De Zapata zapata swamp. [ thunderclap, rain splashing ] zapata is considered the most important wetland in the hemisphere, and despite the embargo, the swamp already draws thousands of visitors from north america every year. Cuba is a way station for nearly 300 species of migratory birds that breed in the United States. Encompassing the infamous bay of pigs, every fall, zapata is now home to a different kind of invasion. Clouds of warblers, ibis cranes and herons leave their summer homes along the eastern United States on a direct flight to cuba. Millions of birds in flocks so enormous they blanket the sky on radar images. Some fly over 1,500 miles, from as far north as new england and canada. Many spend their winter here in the caribbeans largest protected wetlands. Some will simply pause before hopping across the caribbean all the way to south america. Sprawling mangroves, forests and lagoons provide ideal habitat for the visitors and also for birds found nowhere else on earth the cuban parrot the multicolored cuban tody, and the islands National Bird the cuban trogon. But below the surface of zapatas vast swamps lives one of cubas oldest most iconic creatures. One that once lurked throughout the caribbean but is now found only here in its last refuge the cuban crocodile. The cuban croc shares the swamp with its larger cousin the american crocodile. But what it lacks in size it makes up for with a notoriously aggressive temperament. Among the fastest crocodiles in the world the cuban croc has evolved feet with less webbing, to enable powerful bursts of speed. Known as the pearly crocodile because of its yellow and black coloring the croc has powerful jaws for crushing its prey turtles, crabs and fish. Its best known for jumping out of the water to snatch small mammals from overhanging trees. Cuban crocs once ranged all the way to the Cayman Islands and the bahamas. But overhunting and competition for habitat have now confined them to cuba. As few as 3,000 animals now hang on to survival in zapata swamp. Roberto toby ramos is cubas leading authority on the cuban croc. For over 30 years, toby has navigated the waterways of zapata on a quest to understand these ancient reptiles. The cuban crocodiles prefer the freshwater marshes deep inside the swamp. Tobys team has to wait for the summer rainy season, when the water is high enough to access their nesting grounds. With only the most basic tools theyre just beginning to uncover the mysteries of the worlds rarest crocodile. Interpreter the cuban crocodile is almost completely unknown. All weve done is try to give answers to basic questions of ecology where are they how many are there their reproductive success and their habitat. I dont think the most important thing is to know the number of animals, but rather what is the stability of the population. Is this population increasing, is it stable or is it decreasing . Narrator the team heads deep into the muddy mangroves to conduct field surveys on the swamps feistiest inhabitants. [ men speaking spanish ] interpreter the cuban crocodile is considered one of the most aggressive crocodiles. It can be dangerous at any moment. God gave him many teeth, and he gave them to him for a reason. You have to be careful and have an understanding and experience with animals. B