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Central America

Cocos Island has been described as an underwater Serengeti. Its abundant marine wildlife has made the region a magnet for scientists and SCUBA enthusiasts, who often rank the waters as one of the top ten diving spots on the planet.

Located in the eastern Pacific Ocean, 350 miles off the coast of Costa Rica, Cocos Island National Park is as lush and beautiful as it is remote. It is located approximately half-way between the Costa Rica mainland and the Galapagos Islands, but it couldn't look more different than its more famous sister islands, with lower rainfall and relatively dry conditions.

Jacques Cousteau described Cocos Island as the most beautiful island in the world ,and it easy to see why. The rugged landscape makes for stunning scenery: waterfalls tumble down the mountains, turn into streams and rivers, and then cascade straight into the ocean from 600-feet sheer cliffs. Thick tropical forests that cling to volcanic mountains blanket the island, and it is ringed by lush cloud forest at the 2,000 ft peak, all fed by 20+ feet of annual rainfall.

A haven for pirates for hundreds of years, who visited its shores to stock up on water, coconuts and other provisions and who left behind legends of hidden treasure that have attracted treasure hunters for hundreds of years, including President Franklin D. Roosevelt, who visited the island three times.

Today, it is Costa Rica's most inaccessible National Park, with accommodations only for about 30 Park Rangers, and can only be reached by a 30+hour voyage by boat. Nonetheless, thousands come to visit every year, not to search for buried treasure on the island, but to experience its underwater treasure.

Underwater, Cocos Island is even more dramatic than above: A shallow fringing reef encircles the island's bays and then the seafloor drops sharply to a topography of submerged massifs and valleys where deep and shallow currents mix together. The unique confluence of ocean countercurrents, wind currents, and underwater mountains combines to create an ecosystem that supports one of the most amazing displays of marine life on the planet.

Up close divers view schools of hundreds of scalloped hammerhead sharks, which spend their days being "cleaned" by the butterfly and angelfish that pick parasites from around their gills. Also regularly seen are hundreds of whitetip reef sharks resting on the sand or hunting in packs in the shallow coral reefs at night. Many other sharks live in the Cocos waters in significant numbers, including the Galapagos, silky, and blacktip, along with the gentle, filter-feeding whale shark. Tiger sharks, some more than 12 feet long, started showing up recently and are often spotted chasing green sea turtles. Also, there are marbled, spotted eagle, and majestic rays and giant mantas that glide by like silent stealth bombers.

There are few other places in our world's oceans that equal the sheer variety and number of marine species found near Cocos Island. It is like an underwater Serengeti. Cocos' abundant marine wildlife has made the region a magnet for scientists and scuba enthusiasts, who often rank the waters as one of the top ten diving spots on the planet. Now marine biologists and divers are teaming up to understand the unique characteristics of the region--and to protect its underwater inhabitants.

The waters also abound with many species of marine mammals. Pods of bottlenose dolphins hunt with vast schools of yellowfin tuna, and humpback whales pass by Cocos on their annual migrations. Orcas--those massive predators that embody an impressive combination of size, strength, and agility--were first spotted in the park in the fall of 2011.

If you don't own your own yacht or sailboat, visitors are likely to come aboard the vessels of the two companies that provide amazing live-aboard experiences for SCUBA divers. Our sea turtle tagging and hammerhead shark expeditions, which take volunteer "citizen scientists" to help with our conservation project, has exclusively worked with the UnderSea Hunter Group, using their largest and newest vessel, the 130-foot (40 m) Argo.

Equipped with eight state rooms, each with its own murals of underwater life, and accommodating about 16 passengers, the vessel is both beautiful and spacious with three outside decks, two parlors, as well as a roomy dining room where gourmet meals are served.

Once you arrive at the island after the day and half crossing, two motorboats are unloaded by crane that serve as transport and dive platforms for a week of exploring deep beneath the surface. Divers enjoy up to four dives a day, maximizing their time underwater with the use of enriched air (Nitrox). After three relatively deep dives, the last submersion of the day is often a night dive by divers equipped with special flashlights to locate the famous white-tips feeding frenzies in Manuelita Coral Garden. Unlike many shark diving opportunities elsewhere, sharks are not attracted using chum, but naturally occur here in mind-boggling numbers.

In addition to some of the most fantastic diving in the world, the Argo also comes equipped with a one-of-a-kind three-person submarine, the DeepSee, that will take clients down 1,000 feet into the dark abyss to glimpse marine life few have ever seen such as the ancient-looking jello-nose fish and the almost mythical deep-water prickly shark. The view from DeepSee's acrylic sphere is very unique, with a 360-degree field of vision and a 4-inch thick acrylic sphere, which seems to disappear when immersed, giving the astonishing sensation of total freedom.

When not diving or exploring the island, one can also use the kayaks aboard the Argo to explore the islands remote coastline.

All this wildlife creates a bonanza for scientists interested in the migrations of these mysterious species and a dedication to understanding the biological and physical conditions that make this place so special. For conservation biologists, the need to know goes beyond curiosity. Their commitment goes to the collection of data that will inform better policies to protect these species from extinction.

PHOTO CREDIT = Shmulik-blum / Deepsee Submersible

But Cocos Island is threatened. Despite its remote location 350 miles from the Central American mainland and its designations as a National Park and United Nations Biosphere Reserve, it faces the same threats ocean ecosystems do everywhere on the planet. While regulations boast a 12-nautical-mile no-fishing zone around the island , illegal pressures and industrial overfishing leave their detritus; plastic pollution washes in on currents from far away places, and climate change threatens to unravel the unique confluence of currents, winds, and waves that make this place such a rich and bio-diverse ecosystem.

As a small conservation-oriented environmental organizations. Our solution has been to enlist the SCUBA diving community as citizen-scientist assistants. The dive expenses collected from these volunteers are used to employ the vessel and pay for the equipment and supplies. In exchange, these divers get the opportunity to directly participate in the research by catching turtles underwater, tagging sharks, recording data, and photo documenting the process, while enjoying the wonders of diving Cocos Island. Treated to lectures at night, training in research techniques during the day, volunteers help capture turtles underwater, and bring them aboard, where they can help with, measure and tag these beautiful and endangered animals. Volunteers with "spear gun" experience may also get a chance to tag a hammerhead shark. We continue to assemble a small but growing hard-core group of enthusiastic "regular" research assistants, some who have made as many as five trips to Cocos within the past three years, and with most trips filling up with 50% or more repeat clients.

An international political movement is growing to protect Cocos and the marine wildlife of the Eastern Pacific. Costa Rica has announced a new Seamounts Marine Management Area, a 9640 km2 area surrounding Cocos that will attempt to regulate fishing activity, and a coalition of organizations have formed the High Seas Alliance to convince the United Nations to create mechanisms for protecting vast regions of the ocean beyond the national jurisdiction of any single nation. Lastly, we are working to ensure that current regulations are enforced, and inadequate rules are improved and strengthened.

To become a volunteer research assistant on an upcoming Cocos expedition, visit

Your expenses may be tax-deductible because you are part of a non-profit scientific expedition.

ABOUT THE AUTHOR: Todd Steiner is a biologist and executive director of Turtle Island Restoration Network (, an international environmental organization headquartered in California.