"Far out in the eastern Pacific is a scattering of islands ruled by the brutal forces of nature" "a land ravaged by fire" "At the mercy of an ocean that can nourish but also cripple" "a world in turmoil" "This is the story of how life in Galapagos is shaped by the relentless forces of change" "Past, present and future" "Galapagos lie 600 miles off the coast of south America right on the equator" "It's one of the most volcanically active groups of islands in the world" "And on its western edge towers the most imposing, most hostile of them all a colossus called Fernandina" "In the last 200 years this volcano has erupted at least 24 times" "Its caldera towers a mile above sea level but there's one animal that has no option but to scale its summit" "the land iguana" "Every pregnant female needs to find a patch of volcanic ash in which to lay her eggs" "But suitable sites are few and far between and the best, warmed by fumaroles" "lie right on the rim of this giant" "Climbing there is a punishing ordeal which can take weeks" "This female has not timed her journey well" "All the good sites have been taken, so she has no choice but to challenge those in residence" "Aggressive body language can sometimes force a victory but the rightful owner won't relinquish her ground easily so it's all or nothing" "A ruthless catfight" "The pregnant female is sent packing" "evicted from the prime nesting grounds by her rival" "She's now forced to look elsewhere" "But the only other suitable sites on Fernandina lie deep within this giant caldera half a mile down" "She must make a terrifying decent" "The smallest slip could be fatal" "Countless iguanas have been buried by landslides" "But this female has a lucky escape" "For any animal, finding a foothold on Galapagos is tough work" "This cluster of islands are the product of a volcanic hotspot where scorching rock rises from hundreds, possibly thousands of miles beneath to punch at the earth's crust" "There're 6 highly active volcanos in Galapagos today" "One erupts every few years" "Sometimes for months at a time" "Volcanism is the fundamental force in Galapagos" "It can build an island in just tens of thousands of years" "And it can wipe out life in an instant" "After such catastrophic events, animals and plants are forced to find new ground" "The fresh sinewy lava fields seem as lifeless as Mars" "But the lava cactus is a tough pioneer" "It's one of the first plants to invade this baking hot terrain storing moisture in its succulent stems" "And where the lava reaches the coastline, mangroves anchor themselves to the rocks" "Four species have managed to colonize the brittle shores of Galapagos" "Their salt-tolerant seeds brought here on the ocean currents" "Settling in bays and inlets the roots accumulate all sorts of silty debris helping to offer life a purchase on the shoreline" "Mangrove forests are crucial nursery grounds for fish fed by plankton and nutrients flowing in and out with the tides" "The tangle of vegetation also provides welcome shade from the equatorial sun" "But even mangroves struggle to settle on the newest and most exposed lava shorelines" "There is, however, one animal that has learnt how to benefit from this harsh, volcanic terrain" "The Galapagos fur seal" "Its ancestors arrived here long ago from the sub Antarctic" "To escape the midday heat, they've discovered cold hideouts" "Lava grottoes formed by networks of broken lava tubes" "The labyrinth of caves and tunnels provide perfect shelter for fur seals the smallest of their kind in the world" "They're a third the size of their sea lion cousins which also visit these grottoes" "Fur seals have naturally thick pelts which provide good insulation helped by air trapped among the fur" "Big bulging eyes allow them to hunt in the dark a strategy that avoids direct competition with sea lions" "Though fur seals normally court on land adolescents will sometimes test the water with one another beneath the waves" "Geological force in Galapagos has created a cluster of islands of all shapes and sizes" "Some are pillars of compacted ash" "Others forged from explosions of lava" "More than 100 islands, islets and rocky outcrops sprinkle the ocean" "The most unusual lies in the far northwestern reaches of the archipelago" "Roca Redonda" "This giant slab of an unscalable rock, stands a thousand feet tall and is a precious outpost for nesting seabirds" "Swallow-tailed gulls are among the rarest and most exquisite" "They are the only nocturnal gulls in the world and they forage at night for small fish and squid in the surface waters aided by their unusually large eyes" "This island teems with life" "And the productive seas that envelop it hide a secret to its wealth" "There's far more to Roca Redonda than meets the eye" "This island is actually the tip of a giant undersea volcano nearly 2 miles tall and 12 miles wide" "Bathymetric studies, examining the depths of the ocean using sonar tracks give the archipelago a whole new dimension" "Galapagos is a chain of submarine volcanos but have coalesced into a vast underwater platform" "This monumental plinth drastically changes the rooting of the currents that sweep its flanks" "It forces the cool, Cromwell current heading in from the west to surge up from the ocean floor" "As night falls this mineral-rich upwelling" "brings the supernatural to Galapagos" "The most bizarre creatures rise from abyss" "A vertical migration in a 3-Dimensional world" "Some of these ocean vagrants are floating fortresses providing precious shelter" "For others, like this mantis shrimp larvae being small and inconspicuous is key to survival" "Young slipper lobsters are exquisite glass sculptures" "While comb jellies are far more flamboyant beacons of color in a sea of darkness" "Galapagos as it's never been seen before" "As day breaks the nutrient-rich Cromwell current is bathed by the equatorial sun triggering blooms of microscopic algae that feed an explosion of life" "This vital current has helped some of the strangest Galapagos creatures like these cold water penguins to live at this latitude" "The Cromwell current is only one of many that feeds Galapagos" "Flowing in from the south, comes another cold current the Humboldt merging with the south equatorial current heading west" "And from Central America, comes the warm Panama flow" "This current is poorer in nutrient than the others making these northern waters the least productive" "Animals here need to be resourceful" "Shoals of big eye jacks gather at particular cleaning stations attracting the attention of colorful barber fish" "The barber fish like to feed on skin parasites from the Jacks" "It's a mutually beneficial arrangement" "Despite being on the equator" "Galapagos has a limited number of warm stable pockets of water" "There're just a couple of dozen species of coral" "Pavona corals bear the scars of an assault by Guineafowl Puffer fish" "They pluck crunchy mouthfuls of algae" "Coral errosion helps to create an important feeding ground for spotted eagle rays" "They prefer corners of Galapagos where the remains of corals and shells mingle with eroded lava" "They're rich in mollusks and crustations which the rays root out with their powerful, crushing jaws" "These aquatic prairies are also home to rather nervous local residents" "They seem to find the rays particularly intimidating although there's no real threat" "Galapagos garden eels who intercept plankton passing by" "In the rest of Galapagos cold and fertile waters prevail nourishing fields of green algae richer here than anywhere else on the equator" "This is an important food for gangs of yellow-tailed surgeon fish" "This algal farmer, a solitary damselfish suddenly finds his harvest hijacked by marauders" "These marine pastures are a choice habitat for an ancient ocean wanderer the Pacific green turtle" "It's thought the Galapagos turtles are a unique subspecies as they are unusually dark" "Perhaps to help them absorb the sun's warmth and cope better in these chilly waters" "Here is one of the richest concentrations of green turtles anywhere in the Pacific" "Green turtles time their gathering carefully" "For a few month a year they come together to greet and mate" "Even in the most challenging conditions" "Nothing stops this ambitious male from completing the task in hand" "Most green turtles lay their eggs on these shores during the warmer season when the Humboldt current slackens" "Perhaps that warmth helps with incubation" "But their hatchlings will emerge several months later" "At a time when this cold current reestablishes itself with gusto" "For half the year, the Humboldt current dominates Galapagos" "arriving with cool and dry southeasterly trade winds" "And it brings with it the 'Garua Season'" "The misty season" "It's now, with upwelling at its strongest and the water's most productive that turtles, fish and seabirds can bank on a steady supply of food" "Three quarters of the world's population of blue-footed boobies live in the Galapagos" "They react fast when conditions are favorable" "Feet, a handy breaks" "The name booby derives from the word 'bobo'" "the Spanish for 'clown'" "Perhaps because of their exaggerated footsteps" "This courtship dance is a Galapagos ritual" "The higher his foot lift, the better his chances" "Sky pointing builds her interest" "She commits, mirroring his every move" "It's back to basics" "Boobies can switch off their breeding season at any moment if the ocean fails to deliver" "In a good year, 2 or 3 eggs are laid with both parents taking turns to shade and incubate" "Nazca boobies are close relatives of blue-footed boobies but feed much further off shore with a wider hunting range" "They also had a fixed breeding cycle" "But there's a twist in their tale" "Nazca boobies lay 2 eggs and if both successfully hatch there's an age gap of 3-7 days" "The older, larger chick is quick to stamp his authority" "It's a brutal, bullying business" "The elder sibling pushes the other as far from the nest as possible" "Although this happens right under the mother¡¯s beak" "She does nothing to intervene" "The evicted chick now faces certain death through dehydration or predation" "Only one chick ever survives" "No one fully understands why siblicide always occurs among Nazca boobies" "Do the parents produce 2 eggs as insurance policy in case one is destroyed?" "Or is this an evolutionary relic from the past when this species was comfortably able to raise 2 young?" "Whatever the case, for Nazca boobies this system is very effective in a world where the stakes are so high" "In Galapagos, the ocean is both a giver and a taker" "Life has found some extraordinary ways to deal with its mood swings" "But on these remote shores it's still a hostage to the elements" "Every 3-10 years conditions in Galapagos get seriously out of kilter" "It's an event described by the people of Ecuador and Peru as El Nino meaning 'the boy child' because it often begins around Christmas" "Trade winds diminish and the cool Humboldt current slackens" "Failing to make its impact felt in Galapagos" "It is replaced by much warmer surface waters moving east across the Pacific" "Tropical downpours sweep in bringing welcome relief to the land" "Rivers are born" "Plants flourish" "But the impact of El Nino on the ocean is catastrophic" "When it last truck most sea lion pubs starved to death" "Mothers were unable to produce enough milk because of extreme shortages of their main prey" " Sardines" "In some colonies, more than half of all sea lions died" "For marine iguanas the impact of El Nino can be just as dire" "Warmer water wipes out green algae - their main food source" "These islands depend on the ocean as a provider of life but nothing is guaranteed" "Profound geological and climatic forces constantly reshape Galapagos" "Life here is resilient and adaptable to change and with time, it can recover from natural catastrophe" "Galapagos is the most pristine tropical archipelago in the world" "95% of native wildlife is still intact" "Isolation has helped protect these islands" "But in recent times a new force of change has emerged one that is rapidly gaining momentum" "ourselves" "More than 100,000 visitors come to Galapagos each year" "To help support this growing interest the local population was dramatically risen in the last 50 years from less than 2,000 to 30,000" "The resources needed to sustain visitors and residents are spiraling" "There's now a sort of air and sea bridge with mainland South America" "With a constant stream of people and goods" "Galapagos is no longer isolated" "And with this flow of traffic come unwanted species that threatened the delicate status quo" "Already there are more introduced plants here than native ones" "Quinine trees brought in as a medical crop swamp natural habitat where rare birds like petrels nest" "Despite efforts to curb the problems the challenges keep on growing" "Of all the introduced species goats have been the most destructive" "They were brought here centuries ago by buccaneers, whalers and sealers as a reliable food supply but they've stripped the native plants out competing animals like giant tortoises" "Hard though it is the only viable solution to this problem is eradication" "Over the last 2 years tens of thousands of goats have been removed from 2 of the largest Galapagos islands" "The land now has a chance to recover" "Galapagos was, for centuries feared and reviled" "But ever since Charles Darwin's visit nearly 200 years ago we've seen these islands in a new light and it has captured the attention of the world" "This archipelago is a fascinating crucible for life" "It continues to evolve and surprise" "So great was its impact on Darwin that he would later claimed the Galapagos islands to be the origins of all his views" "Today, it is our impact on Galapagos and how we choose to manage it that will determine the island's future" "If that succeeds, it can point the way for everyone" "Galapagos, is, after all, a microcosm of our planet" "Transcription by Andrew  Hattie"