By freedivinguae


Whale shark viewing at Oslob, a popular tourism site in the Philippines, is facilitated by hand-feeding the animals with shrimp. The long-term impacts of this provisioning are not well understood.

Photograph by David Doubilet, National Geographic

In the Philippines, whale shark tourism is a booming business. But questions have arisen about how this activity could harm the animals.

Welcome to Oslob, home of the whale shark selfie.

In this town, near the southern tip of Cebu Island in the Philippines, whale sharks are a big draw. Tourism is booming for people who want to watch, swim with, and take photographs next to the world’s biggest fish.

Since it began in 2011, Oslob’s whale shark-watching operation has become the largest such venture in the world. But the operation is controversial, because whale sharks don’t naturally gather here, unlike other such sites in the country. The Oslob sharks are hand-fed, and this essentially guarantees they will show up to thrill guests, who can snap close-range photos.

The situation raises thorny questions, for example about the impact of feeding and human interaction on the animals, the sustainability of such an operation, and the conservation value. Do the benefits outweigh potential downsides?

These questions are not merely academic, considering whale sharks are globally endangered and their numbers in the Philippines region are in steep decline. Prior to 1998, when whale sharks gained national legal protection, hundreds of whale sharks were killed in the Philippines each year for their meat and fins.

But poaching still happens here and elsewhere, since demand and markets for whale sharks remain, a primary destination being China—and a single animal can fetch tens of thousands of dollars. Their meat, fins, and oil are sold for food, and their skin for bags. (Related: The world’s largest whale sharks are disappearing.)

Sunrise in Oslob

Oslob’s day begins at six in the morning, when the first tourist arrivals listen to a short briefing—no touching, no riding, no flash photography, and keep at least six feet away from the sharks at all times. Visitors don masks, snorkels, and life jackets and board outrigger boats to see the sharks. In the “interaction area,” about 150 feet from shore, the boats line up and the show begins. Feeders in small, one-person outrigger canoes dish out handfuls of thawed shrimp to the waiting sharks, many of which time their arrival to within a few minutes of feeding.

It’s called “watching,” but there’s just as much “posing.” It’s a strange sight: A line of tourists in the water hold on to the boat’s outrigger. Their backs face the sharks while they mug for the cellphones being clicked by the boat operator. The beasts are the backdrop.

Guests are told they can go to jail if they touch or get too close to the sharks, but researchers have found that more than 95 percent of swimmers break the rules—often inadvertently. It’s a melee out there, and contact happens.

Almost all whale sharks which visit Oslob are juvenile males. Most are only temporary visitors, but a few become year-round residents.

Photograph by David Doubilet, National Geographic

Some of the sharks swim languidly at a 45-degree angle, as though their tails were weighted. Others stay almost motionless, entirely vertical, slurping the shrimp with muscular gulps—a whirlpool of water and food disappearing into their postbox-slot mouths.

Feeding ceases at midday. The sharks dissipate and the boatmen disperse. Show’s over, until tomorrow.

Who Benefits?

Shark viewing is a growing sector of the tourism industry, and other operations (in other countries, for example) use baiting or provisioning to attract animals. It’s often billed as ecotourism, but that can sometimes seem a stretch. Ecotourism, at its best, draws humans into the world of the creatures they encounter. It has low impact on ecosystems and a demonstrable conservation value. But many argue that’s not exactly what’s happening here.

There are some benefits to the enterprise. For one, the whale sharks in Oslob are still around. “The scene at Oslob is chaotic, and the controversy is real,” says my colleague David Doubilet, who has been photographing in the Philippines for a forthcoming National Geographic feature. “But the sharks are alive and not lying dead, fins removed, in cold storage somewhere in Asia.”

Another likely upside: A reduction in fishing pressure around Oslob. The 170 or so members of the local fishermen’s association, who feed the sharks and ferry the guests, no longer need to catch fish for food from increasingly depleted reefs. Likewise, fishers nearby can earn a living supplying the several hundred pounds of shrimp needed for each day’s shark food, thus placing less pressure on declining fish stocks.

The giant beasts also benefit the local economy. At night, the Oslob coastline twinkles with the lights of more than 50 hostels, resorts and guesthouses, as well as local homes. “The whale sharks brought the lights,” one resident told me. Who would imagine that prosperity could come to Oslob by something as simple as throwing handfuls of shrimp into the mouths of passing sharks?

Enthusiasm, Concern

Mark Rendon, a 26-year-old boatman, has been part of the Oslob operation for three years. He used to work away from home in Cebu City as a government clerk. Now he earns more, travels less, has fewer expenses and lives at home with his family.

Sixty percent of the tourism revenue goes to the fishermen, according to Rendon. Thirty percent goes to the municipality and 10 percent to the local village.

It is not just the fishers who have benefited. “Housewives have become entrepreneurs,” Rendon said—selling leis, souvenirs, fruit smoothies, snacks.

As far the sharks go, most visit for a few days or weeks and move on. But some—four percent of the total—become year-round residents. Scientists worry that sharks that take advantage of the free feed for prolonged periods may suffer ill effects, both physiologically and behaviorally.

Whale sharks have been nationally protected in the Philippines since 1998, but poaching persists in this area and elsewhere in the animal’s huge ranges.

Photograph by David Doubilet, National Geographic

While research has begun, conducted for example by the Large Marine Vertebrates Research Institute Philippines, basic questions about the influence of this feeding remain unanswered. The shrimp they’re fed is a less diverse mix of planktonic creatures than what they would consume naturally. It’s not junk food, but neither is it necessarily a healthy diet.

Whale sharks associate boats with free food, and that connection could lead them into danger elsewhere. Almost half of the whale sharks studied at Oslob have propeller cuts on their bodies, which must have happened elsewhere, since the operation uses only hand-paddled vessels. These animals may also be more likely to one day approach a shark-fishing vessel. Whale sharks have been nationally protected in the Philippines since 1998, but poaching persists here, and elsewhere in the animal’s huge ranges, where they may not necessarily be legally protected.

Guilty Pleasure?

It’s also unclear what happens when these migratory animals are conditioned to remain in one place for an extended period of time, and what effect that might have on their patterns of social interactions and movement. Of the 650 individual whale sharks that have been identified in the Philippines, a quarter have been seen at Oslob. That’s a significant portion of the population being exposed to unknown survival risks.

Some would argue that whale sharks—like whales, pandas, polar bears, tigers, and elephants—are ambassadors for the natural world: charismatic creatures that move us to care for Earth and its multitudinous life. And perhaps that benefit might offset a small degree of disturbance to these creatures.

For every grinning Oslob tourist snapping a photo with a shark, could there be another who looks into the eye of that great spotted giant and sees something of immense intrinsic worth, whose existence must be protected? Or are these sharks primarily narcissistic props?

A recent study of how tourists perceive the Oslob whale shark operation found that many visitors recognize that feeding an endangered species for tourism purposes is ethically problematic—if not morally wrong—but participate anyway. Some researchers describe this type of justification as a “guilty pleasure.”

Fishers I spoke to feared that the government might decide the conservation risks outweighed the economic benefits and ban shark-feeding. That would, in effect, end their business. They hope the benefits will be seen to offset the risks to the sharks.

For Rendon, it’s simple. “I want to do this forever,” he says.

For advocates of the creatures, it’s equally plain: Wildlife should not be fed.

Meanwhile, whale shark tourism—with its unknown effects on the animals—shows no signs of slowing down.



By freedivinguae

Mexico stops hotel project at Playa Xcacel, large sea turtle nesting beach

Playa Xcacel sea turtle

Environmental authorities in Mexico say they have denied permits for a proposed hotel near one of Mexico’s most important sea turtle nesting beaches on the Caribbean.

The 520-room hotel project would have erected 23 buildings and an artificial lake on property just inland from the Xcacel beach, north of the resort of Tulum.

The federal Environment Department said in statement late Monday the project could threaten Xcacel, and called it “the site with the largest observed nesting of sea turtles on the entire Yucatan Peninsula.”

The beach is a nesting site for loggerhead, hawksbill and green sea turtles, and part of the land is considered a protected area.

But parts of the property behind the beach have been the target of real estate development plans since the late 1990s. Environmental authorities have turned down at least one previous proposed “eco hotel” project there.

On Mexico’s western coast, President-elect Andres Manuel Lopez Obrador announced he has blocked another conservation proposal. Lopez Obrador will take office Dec. 1, but outgoing President Enrique Pena Nieto has made it clear he won’t cross Lopez Obrador.

Some environmental groups had been pushing Pena Nieto for a near-total ban on almost all fishing in the upper Gulf of California, also known as the Sea of Cortez.

Some activists had proposed the ban to protect the critically endangered vaquita porpoise, of which fewer than 30 remain.

Vaquitas have been decimated by nets set for the totoaba fish, whose swim bladder is considered a delicacy in China and commands high prices. Poachers often hide among legitimate boats to catch totoaba and sell the bladders. The government has struggled to enforce a ban on gill-net fishing in the area.

But Lopez Obrador said over the weekend that “we have gotten visits from fishermen who were worried that the federal government would decree a fishing ban in the Gulf of California,” Lopez Obrador said. “We talked with Pena Nieto and that decree has been blocked.”



By freedivinguae

Red Sea Corals in ‘Serious Danger’, Egyptian NGO Warns

Coral reefs and water plants in the Red Sea are in serious danger of dying. (Shutterstock/File)

The HEPCA (Hurghada Environmental Protection & Conservation Association) NGO warned on Sunday that coral reefs in Hurghada, Red Sea are in serious danger as a result of fishing with explosives and throwing waste in the sea, according to a recent statement.

The statement added that coral reefs are some of the richest natural habitats provide shelter for many marine organisms. They are also an economic treasure thanks to their major role in encouraging tourism.

The HEPCA said it has taken strict measures to protect coral reefs, such as the establishment of the largest project for moorings, cleaning reefs of solid waste, and prosecuting violators.

The HEPCA posted videos on its Facebook page warning against practices that harm coral reefs and of all the important measures taken to preserve them.

Egypt’s coral reefs are found mainly along the coasts of the Red Sea, the Gulf of Suez and the Gulf of Aqaba, where more than a thousand different fish species live among 250 kinds of coral.

Red Sea reefs are cited as among the richest in the world for overall species diversity. Coral reef degradation has increased dramatically during the last three decades, particularly along the Egyptian Red Sea coast due to man-made disturbances such as global warming and other stressors, according to a study from the Benha University.



By freedivinguae

Sea cow rescued in Lagos

Sesan Olufowobi

A manatee, popularly known as sea cow, has been found in a riverine community in the Agboyi-Ketu Local Council Development Area of Lagos State.

The Permanent Secretary, Ministry of Agriculture, Dr Olayiwole Onasanya, said immediately the ministry got the information, the state government moved to rescue the huge aquatic herbivorous mammal before residents could turn it to food.

He said the mammal was caught by the trap set by a fisherman in the area, adding that the government decided to rescue it because it was an endangered animal.

Onasanya said, “The mammal is an endangered species which breeds only a single calf once in two years. It is listed by the World Conservation Union as a specie vulnerable to extinction because of its meat, bones, and skin, which can bring wealth to poachers.

“The mammals are in three species of West Indian, West Africa and Amazonia, with the highest population in Guinea-Bissau, the lagoon of Cote d’voire, the southern portions of Niger River in Nigeria and the coastal lagoon of Gabon.”

The permanent secretary added that the manatees measure up to 13 feet with as much weight as 590 kilogrammes, which graze on water plants in tropical seas and consume about 10 to 15 per cent of its body weight in vegetation.

He said the state government was committed to continuous formulation of policies geared towards the preservation of wild animals in order to boost the tourism potential of Lagos.

He noted that the manatee had been kept safely in the custody of Origin Zoo in the Ikorodu area of the state.

“This animal can be a source of tourist attraction to the state if properly taken care of. To this end, the government has already taken all necessary steps in providing a conducive and habitable environment for the sea cow,”  Onasanya said.

The fisherman who trapped the mammal, David Oyenuro, said he was happy that the government rescued and had decided to preserve the animal.

He urged the government to continue to support fishermen, saying their fishing implements get damaged when they encounter huge aquatic animals such as the manatee.



By freedivinguae

Great Barrier Reef Shows Signs Of Recovery After Mass Coral Bleaching In 2016


Only two years ago Australia’s Great Barrier Reef experienced a mass coral bleaching event that left the largest living structure in the world forever changed. Scientists discovered the events caused the collapse of the ecosystem for 29 percent of the 3,863 reefs in the giant coral reef system.

Thanks to a milder 2017-2018 summer, Tourism and Events Queensland issued a “positive update” on the reef last week, reporting there are “substantial signs of recovery” in areas that were affected the most.

According to the Queensland State Government, The Reef & Rainforest Research Centre (RRRC), a nonprofit organization, reported the milder summer temperatures and other factors including cooperation among science, and government in supporting the reef’s recovery, have contributed to the reef’s health. Lead researcher Roger Beedeen said it was an encouraging sign of the ability of corals to repopulate and regrow after damage.

“What we’re now witnessing in many areas between Cairns and Bowen, where Cyclone Yasi swept through, is good regrowth of surviving corals and large numbers of new coral colonies,’’ the Great Barrier Reef Marine Park Authority scientist said.

Visible from space and greater in size than the United Kingdom, Holland, and Switzerland combined, the reef is home for a variety of animals, including thirty species of whales, dolphins, and porpoises, six of the world’s seven species of threatened sea turtles, at least 30 species of mammals, and more than 1,500 fish species.

Source: Getty

Warmer ocean temperatures put stress on coral, leading to coral bleaching, meaning the higher temperatures essentially “cook” the coral, turning the once colorful algae ghostly white. If “cooked” for too long the structures die off, but some coral can survive if it has time to recuperate.

Though the damage to the reef has been extensive, the government announced earlier this year that it would spend about $365 million on reef conservation efforts, making it the largest single investment for reef conservation and management in the country’s history.

Deloitte Access Economics reports the reef to valued at over $56 billion due to the tens of thousands of jobs it provides and how it contributes to Australia’s economy.

Source: Deloitte/Great Barrier Reef Foundation

“Valuing nature in monetary terms can effectively inform policy settings and help industry, government, the scientific community and the wider public understand the contribution of the environment, or in this case the Great Barrier Reef, to the economy and society,’’ the Deloitte report said. “The tight and unforgiving deadline the Great Barrier Reef is up against necessitates an understanding of its true value to know what kind of policy action is required in response.’’

“These experiments show taking action on climate change reduces the loss of coral reefs and has many benefits for the Great Barrier Reef and its dependent people and industries.,’’ the report found. “These types of scientific experiments, in combination with field studies, have built a strong case for action on climate change.’’

Despite the good news by researchers on the reef’s progress, RRRC Managing Director Sheriden Morris, says the reef’s recovery is “contingent on environmental conditions” and that the reef “may suffer further bleaching events as the climate continues to warm.”

“When a reef is reported as ‘bleached’ in the media, that often leaves out a critical detail on how severe that bleaching is, at what depth the bleaching has occurred and if it’s going to cause permanent damage to the coral at that site,” Morris said in the statement, adding that the Barrier Reef “has significant capacity to recover from health impacts like bleaching events.”


By freedivinguae

Sea turtles that eat 14 pieces of plastic have 50 per cent chance of dying, CSIRO study finds

An alarming number of turtles tested in Moreton Bay had consumed plastic, Mr Miles said.

Scientists have drawn a link between the amount of plastic a sea turtle consumes and its likelihood of death, with an estimated half of all sea turtles having plastic in their gut, according to CSIRO researchers.

The CSIRO said it was previously unclear how much plastic could kill sea turtles and whether they could ingest it without significant harm.

A study, published today in Scientific Reports, has found that once a turtle had 14 pieces of plastic in its gut, it had a 50 per cent likelihood that it would cause death.

Principal research scientist Chris Wilcox at the CSIRO in Hobart said they estimated 52 per cent of sea turtles had plastic in their stomach.

“What we found was that when the turtle eats the first piece of plastic, it has about a 20 per cent chance of dying due to that one piece of plastic and as they eat more plastic, the chance that they die goes up,” he said.

“We find hundreds of pieces of plastic in some turtles, everything from thin film to rope to fishing line, anything you see in your daily life we see in a turtle.”

Dr Wilcox said they were previously unsure about the impact plastic had on sea turtles.

“It’s really widespread but it might have been that the turtles can live with plastic in their gut no problem,” he said, “It might be that it’s relatively deadly.

CSIRO research assistant Qamar Schuyler said they studied nearly 1,000 turtles found dead and washed up on beaches around Australia.

“In one tiny little flatback turtle we did find whole apple stickers, the stickers that come on fruit,” she said.

“We find a lot of soft plastics in the older animals, it could be plastic bags it could be lolly wrappers.”

Dr Schuyler said the next step was to estimate the impact plastic had on turtle populations.

“Now that we know how much plastic it takes to kill a turtle, we can combine that with previous work that we did which looked at the probability of ingestion of plastic by turtles,” she said.

“We can come up with a global mass mortality estimate of how many turtles globally are being killed by plastics.”

Animal ecology lecturer at the University of the Sunshine Coast Kathy Townsend said sea turtles in different parts of the world had varying amounts of debris in their gut.

“It really depends upon what part of the world you’re looking at,” she said.

A recent study in Uruguay found almost 100 per cent of the sea turtles had marine debris in their gut.

“We’re not talking little bits, we’re talking hundreds of pieces,” Dr Townsend said.


By freedivinguae

Celebrating whale sharks responsibly

Celebrating whale sharks responsibly
Illustration: A whale shark approaching the surface. (Shutterstock/Andrea Izzotti)

Few may have been aware that Aug. 30 was International Whale Shark Day, a day dedicated to celebrating and raising awareness of the largest fish in the world. The shark can grow up to 18 meters long and weigh as much as 20.6 tons, about the size of a school bus.

A whale shark is a shark not a whale; it is a fish that breathes using gills and because it is a shark, its skeleton…


By freedivinguae

Swim with sea turtles on this Holokai Catamaran cruise

I’m 15 feet underwater, eye to eye with one of the largest sea turtles I’ve ever seen, just a few miles off the golden coast of Waikiki.

Out of breath, I reluctantly turn away from the honu (Hawaiian green sea turtle) and swim up for air. The moment is so serene, and a polar opposite of the experience I went through earlier in the day, rushing through traffic and the concrete jungle of hotels and parking lots on shore.

When you’re not snorkeling with the turtles, check out the dreamy views of Waikiki and Diamond Head.
Photo: David Croxford

Back on the water’s surface, I spot Holokai Catamaran, a large double-hull vessel anchored nearby, its white exterior offset by a bright orange sail. I’m on its Turtle Canyon Adventure Sail, led by Capt. Rich, a friendly man with a tanned, muscular physique and numerous tattoos. “We’re going to be out at sea for around 2 1/2 hours, unless something goes horribly wrong,” he joked earlier when we boarded. He’s accompanied by Geronimo, a tall ship hand with a wide smile. Most of my sightseeing in Waikiki has been from its busy streets and beaches. But now, looking back at the urban architecture from the ocean, away from the cars, bars and noise, the tourism hub appears quieter, calmer.

Only a 10-minute sail from shore, this fabled turtle hot spot is in fact not a canyon at all, but a finger of reef that a wide array of fish call home. Honu with too much algae growing on their shells come here so the resident fish can swarm their backs and feast on the accumulated residue, feeding themselves and cleaning the turtles’ shells at the same time. Capt. Rich puts it more simply, “It’s like a car wash for the turtles and a buffet for the fish.”

Protected by federal and state law, touching the honu is highly discouraged, and can result in a hefty fine.
Photo: David Croxford

Diving back into the warm waters, I find another gargantuan friend, gazing directly at me if for only a moment. “You can look, but don’t touch,” Geronimo told us, explaining how the honu are protected by state and federal law due to their endangered status. Following along on the honu’s massive back, a school of fish bite and nibble at its shell. Slowly lazing around the reef, wherever the turtle went, so did the fish. Fortunately, as this turtle drifted away from the area, a new turtle arrived, ready to get squeaky clean. During my hour-long snorkeling adventure, there was always a turtle around, much to my, and I’m sure the fishes’, delight.

I break away from the crowd and explore the other nooks and crannies of Turtle Canyon. Deep below the surface, I find small schools of fish spread around the area and various sorts of wana (pronounced vaw-naw, sea urchins) tucked into small holes around the reef. Popping back up for air, I spot my fellow passengers diving off of the boat’s hull, some more gracefully than others, but all having a blast. Swimming closer to the catamaran, I see white sands replace the gray reef and the waters shift to a lighter shade of blue, something you’d expect to find closer to shore. Here, families with children float along without a care, talking story with Capt. Rich and Geronimo.

Forgot your snorkeling gear? Don’t fret, Holokai Catamaran lends fins and masks.
Photo: David Croxford

After a little over an hour of swimming, I climb back on board and hear reggae tunes playing from the boat’s speakers as we prepare to leave Turtle Canyon. Capt. Rich points us east, and we sail toward Diamond Head; the second leg of the tour consists of a scenic, lounge-inspiring cruise. Geronimo takes the helm of the makeshift bar to serve beers and juices, and although the drinks aren’t complimentary, the snacks are. Taking a few packs of peanuts, I stretch out and soak in the sun at the front of the ship, where tight netting tied between the two hulls of the vessel serve as a hammock. I try not to drift asleep as my once busy day slows to a snail’s, or more appropriately, a turtle’s pace.



By freedivinguae

Diverse family of algae could help corals survive warming seas



  • Scientists have found that some algae that associate with corals are much more diverse and much older than previously thought.
  • The origin of certain algae occurred at around the same time corals began building reefs on a grand scale around the world, the researchers showed.
  • The diversity of these algae could boost corals’ resistance to higher ocean temperatures.

Some corals stand a chance of surviving the current rise in global sea temperatures, a team of scientists recently reported, thanks to the diversity of their algal counterparts.

They found that the alliance with algae that underpins corals’ ability to form reefs stretches back much further than previously thought, said Todd LaJeunesse, a biologist at Pennsylvania State University and the paper’s lead author.

“Our research indicates that modern corals and their algal partners have been entwined with each other for much longer — since the time of the dinosaurs, approximately 160 million years ago,” LaJeunesse said in a statement. “During their long existence, they have faced severe episodes of environmental change, but have managed to bounce back after each one.”

A reef ecosystem in the Red Sea with divers. Image by Christian Voolstra/King Abdullah University of Science and Technology.

LaJeunesse and scientists from the U.S., Saudi Arabia and South Korea sequenced the DNA and compared the genomes of algae called dinoflagellates that live inside corals and provide them with sustenance as they harvest sunlight to make food. The team also examined the morphological differences between members of the family using high-powered microscopes in concert with computer modeling. The specific family they looked at is called Symbiodiniaceae.

The researchers concluded that this family was much older and more diverse than previously thought.

“Presently, numerous algal lineages, called clades, are lumped into just one genus,” John Parkinson, a coral reef ecologist at Oregon State University and a co-author of the paper, said in the statement. “Using genetic techniques, we provide evidence that the family actually comprises at least 15 genera, including hundreds and possibly thousands of species worldwide.”

The relationship between corals and micro-algae called dinoflagellates in the family Symbiodiniaceae forms the basis of coral reef ecosystems. The flagellated stage is highlighted here before the image of a surface of a coral colony with polygonal polyps in the background. Not to scale. Image by Todd C. LaJeunesse/Pennsylvania State University and Hae Jin Jeong/Seoul National University.

This diversity, combined with the family’s age, likely helped corals to begin constructing reefs on a grand scale.

“The fossil record shows that today’s reef-building corals exploded in diversity around 160 million years ago,” LaJeunesse said. “Finding that the origin of the algal symbionts corresponds to major increases in the abundance and diversity of reef-building corals implies that the partnership with Symbiodiniaceae was one of the major reasons for the success of modern corals.”

As a result of their findings, the scientists are proposing a new naming scheme for Symbiodiniaceae algae.

A reef in the Red Sea. Image by Susann Rossbach.

“Accurate taxonomy (the identification and naming of species) is a critical step in any biological research,” Parkinson said. “This is especially true for studies attempting to understand how the partnership between reef corals and their micro-algae, which are needed for survival and growth, may adapt to climate change.”

He pointed out that stress affected corals in different ways, and the algal species they associated with could determine their chances of bouncing back.

“[When] many corals are exposed to high temperatures they lose their symbiotic algae and die,” Parkinson said. “Others are far more tolerant of heat, and some of this resilience is based on the species of algae they have.”

Reef corals comprise thousands to millions of genetically identical polyps produced by clonal division, which remain attached to each other and create massive colonies, like this Orbicella. The species is an important reef-building coral in the Caribbean, and its symbiosis with micro-algae has been studied extensively. Image by Robin T. Smith.


By freedivinguae

Despite Many Threats, Some Coral Reefs Are Thriving

Despite Many Threats, Some Coral Reefs Are Thriving
A school of twinspot snapper (Lutjanus bohar) use the complex structure of coral reefs for shelter. Credit: Brian Zgliczynski; 100 Island Challenge

RAROTONGA, COOK ISLANDS—Twenty-one degrees, 12 minutes south of the equator, 2,771 miles south-southeast of the southern tip of the island of Hawaii, 30 feet below 4-foot swells, Nicole Pedersen swims slowly, wearing a wetsuit, headband, and full scuba gear and carrying a custom-built plexiglass-and-PVC case the size of a tackle box. Within it, twin DSLR cameras automatically photograph a reef a quarter-mile off the coast of Rarotonga. It’s the last of 12 dives she and colleagues from the Scripps Institution of Oceanography have made over three days of their research expedition here.

Pedersen, 25, is a staff researcher at Scripps, part of the University of California, San Diego, and the image digitization coordinator for a natural experiment called the 100 Island Challenge, launched in the summer of 2016. The images she’s gathering—4 billion pixels comprising 70 to 80 gigabytes of data, just from today—will ultimately help the team build a three-dimensional model of the 100-square-meter (1,076-square-foot) plot of reef Pedersen is swimming over in a lawn mower pattern.

As she gently flaps her black-and-yellow fins, maintaining as constant a speed as is possible underwater where waves and currents can toss her off course, marine ecologists Stuart Sandin and Brian Zgliczynski swim alongside her, counting every fish in the plot and marking on a waterproof data sheet each one’s species and approximate size. The more than 4,000 dives the team will make over five years are the data-collection component of an unprecedented attempt to characterize five examples of every type of reef on the planet—twice—to see how each is responding to climate change, ocean acidification, pollution, overfishing, and the other insults humans have been throwing at many of them with increasing frequency and intensity over the last few decades.


The 100 Island Challenge is so wildly ambitious that even one of its co-leaders, Scripps coral reef ecologist Jennifer Smith, thought it would be absurd to try when Sandin, the project’s lead investigator, and Zgliczynski, a postdoctoral researcher, pitched it to her several years ago. “You guys are idiots,” Zgliczynski says she told them.

Over a dinner of wahoo fillets and Cooks Lager, the local brew, following the first day of diving in Rarotonga, the scientists say they could already see that the island’s reefs, alive with new growth of diverse coral species and crowded with fish scraping away excess algae, are not like those that have dominated the news lately. “Coral reefs are bleaching four times as frequently as they did in the 1980s, scientists say,” read a Washington Postheadline in January. “Coral Reefs at ‘Make or Break Point’, UN Environment Head Says,” blared another January story in The Guardian. “Coral reefs at risk of dissolving as oceans get more acidic,” announced Reuters in February.

Nicole Pederson pilots the mosaic camera system taking images of the coral reef ecosystem off the coast of Rarotonga. Credit: Brian Zgliczynski; 100 Island Challenge

Unchecked coastal development pollutes reefs; illegal, unreported, and unmonitored fishing depletes them; carbon dioxide emissions inhibit their ability to grow; and historic ocean warming has in recent years caused back-to-back bleaching events that threatened reefs worldwide, including potentially as much as half of the Great Barrier Reef’s northern corals. Still, although the bad news is undeniable, it’s not the only story. “And it’s not the story when communities take control of their marine ecosystem,” Sandin says. “When a community is engaged and listens to what’s underwater, they can keep it going.”

The group of scientists Sandin and Smith have assembled thinks at least some reefs have the potential to survive another—inevitable—mass bleaching event like those that struck the South Pacific in the El Niño year 2014-15 and again in 2015-16. Confirming this is vital to protecting them, other scientists agree, because if people view a problem as having no solution, they tend to tune out.

“There are a lot of bad things happening to coral reefs, and to ignore that would be crazy,” says Nancy Knowlton, Sant Chair for Marine Science at the Smithsonian National Museum of Natural History. Nevertheless, reefs can recover when they are free from other stressors, such as pollution and overfishing, she says, so “simply to have a ‘coral reefs are doomed’ attitude is not particularly helpful, and not particularly accurate.”


Locally, such an attitude could lead to harmful new development, or to dumping sewage on reefs, because what’s the point of denying the permits if the reef is just going to die anyway? The aim of the 100 Island Challenge is to figure out which reefs recover well, why they’re more resilient, and how to transfer whatever properties are saving them—be they biological, managerial, or environmental—to other coral reefs and coral species.

“You’ve got a huge number of islands across the planet that are beautiful, unique storehouses of biodiversity and provide resources for humans, so if we can develop the technologies that are working at each of these sites, they become good test cases for other islands and other reefs,” says Ove Hoegh-Guldberg, professor of marine science at The University of Queensland in Brisbane, Australia.

Sandin and Smith, both 45, who are married, are acting on preliminary evidence that local reefs with good water quality and healthy fisheries are more likely to recover quickly from bleaching. “Some places we work in the Central Pacific did experience quite extensive warming and the reefs did bleach,” Smith says. “We documented that, and we were able to go back and found a lot of corals were actually able to recover.” She also points to corals that have adapted to warm seas, such as those in lagoons that experience temperature spikes daily and seasonally.

Palmyra Atoll, a U.S. Minor Outlying Island between Hawaii and Rarotonga, showed signs of recovery just eight months after a major bleaching event. Smith, who has photographed corals off Palmyra every year since 2009, hypothesizes that the lack of pollution and fishing played a role in enabling its corals to recover so dramatically. “They’re more likely to recover than a reef experiencing runoff, sewage, overfishing, and so on,” she says.

The group has identified 100 reef sites, from the East China Sea to the Lesser Antilles, to serve as a sample of all reef types: those with high to low levels of food (three levels), those with high to low population density (three levels), and high vs. low elevation islands (two levels). That makes 18 combinations, and there are five islands of each. (The leap from 90 to 100 was about “project branding,” Smith explains.)


Trained volunteers in the lab in San Diego tag each species visible in the 3D models, which can show coral babies as small as one square centimeter across, so the experiment provides a nearly complete taxonomy of corals at each site. The scientists also take a fish census at each site, employing more or less the same method used to count elephants in Tanzania.

Recording the location with GPS, they plan to revisit each reef after two or three years and repeat these painstaking processes to see how it’s changed. Temperature, water quality, fish population, coral species, and other variables are measured across the sites. (Expeditions are planned for the same time of year to account for seasonal variability; in any case, with so much data, any such variability will essentially wash out, Sandin says.) By referencing those variables against island factors such as the particular oceanography, the benthic dimension—how much of the ocean bottom is comprised of reef, sand, etc.—and human influences like how much fishing occurs there (and whether it’s for eating or for selling off-island), they hope to find out why the changes have occurred.

The research isn’t merely academic. The hope is that local managers where reefs are suffering will implement policies similar to those in place where they’re doing well. “People are always excited to hear what’s going on on other islands,” Sandin says. At each island, the team seeks partnerships with local fisheries managers and other governmental agencies, scientists, and environmental NGOs representing the people who live on the reefs and depend on them for their livelihoods. The team also provides partners with trip reports and 3D photomosaics of the area at the conclusion of each expedition.

In Rarotonga, before they had even dunked their heads in the ocean, Sandin, Pedersen, and Zgliczynski visited members of the House of Ariki, a parliamentary body composed of traditional leaders from most of the Cooks’ 12 inhabited islands and atolls. The House is constitutionally tasked with making recommendations to the elected Parliament on certain issues—including, currently, a government plan to allow seabed mining of manganese nodules (which the House has embraced), and a proposal to build sewage pipes that will send nutrients into the ocean. The latter could deplete fish populations by encouraging algae growth that will harm the corals; the project is still in the design phase and hasn’t yet been presented to the House.

They met in what had been the living room of a private home where the House now maintains its offices; ceremonial carvings and fabrics, and photos of past traditional leaders decorated the place. A few current members, most of whom are women, wore flowered headdresses. Facilitating the meeting was Teina Rongo, a marine biologist who is well respected locally for his Ph.D. from an American university as much as for hailing from a prominent family on the island.


After introductions and a Christian prayer, the president of the House, Travel Tou, addressed the visiting scientists. “It is important that you came to us because we are not sure if the government is moving forward,” he said. “If we don’t protect the land, the results will be seen in the ocean, so we have a hard job.” Sandin then told the assembled leaders his intentions in Rarotonga and explained the experiment, expressing his hope of finding “good collaborators” among the leaders and elsewhere in Cook Islands. “We are available to engage in conversations to find a way we can learn from one another,” he said.

President Tou replied that in 2017, 15 scientific researchers came through the House, presenting their projects just like Sandin had done. The House endorsed all of them. “We requested, ‘When you finish, please—we want to know what you have found so maybe you can advise things that need to be looked at to protect our livelihood.’” But only one of the 15 had responded.

After the meeting, over lunch at a new restaurant on the north shore that Rongo is convinced will be doomed when the next cyclone hits, he explained how people on the outer islands manage their fishery. Island residents fish using traditional methods such as spears and nets hand-woven from plant fibers—no “European-style” rods or nets—and distribute their catch communally. “They close an area [to fishing] sometimes, and rotate set-aside areas every one or two years,” he said. “They’ve been doing this for hundreds of years.” Little enforcement is needed, but when it is, one punishment is to require violators to sit with the children at community gatherings.

Rarotonga is a different story. The Cooks are divided between a southern group of islands and a northern group, 91 square miles of land scattered across nearly 800,000 square miles of ocean. Rarotonga is in the southern group. The more connected people are to the main island—where the majority of Cook Islands’ 17,000 people are spread out, mostly near the coast, across an area a little larger than Manhattan—the worse they are at protecting their reef, Rongo said. It’s part of Western values’ corrupting influence on local culture: “The mentality is, if you speak English, you’re smart. But we’re losing the culture by losing the language. The ethic of conservation is transmitted through the legends and songs.” Teaching natives how to fish and farm also leads to their caring about the resources, he said. “Even if they go on to be engineers or business people, they’ll have that foundation.”

Western influence here is more than just cultural: A warming ocean confers direct threats to the health of Cook Islanders. Illness caused by eating fish contaminated with the toxin ciguatera is expected to rise with sea temperatures. Warmer oceans increase the frequency of cyclones and coral bleaching events, both of which can increase the abundance of microorganisms that carry the toxin. Rongo, who wrote his Ph.D. thesis on the disease, draws a direct correlation between a series of six cyclones during the El Niño year of 2004-05 and the highest incidence of human ciguatera poisoning on record.


Sandin sits on the stern of the boat the team has hired for about $1,000 a day, festooned with an elaborate array of gear hanging off his buoyancy compensator: Two dive reels, each with a 25-meter (82-foot) cable; a camera; a PVC monopod that attaches to the camera to photograph a set area in order to establish the scale of the 3D model; and a clipboard with the data sheet for the fish count. (Somewhere on his person, he hopes, is a pencil.) He spits into his mask and affixes it over his eyes and nose, then dumps over the side a red float with a GPS attached. It serves the dual purpose of alerting the boat’s skipper, and any others who might happen by, of the presence of divers below, and marking the precise location of the dive so the researchers can find it when they return in two years to survey the site again. He joins the regulator with his mouth, checks its flow on a gauge, and spills backward into the water.

The team has three jobs each dive: gathering images for the 3D photomosaic; counting fish; and deploying devices for in-situ measurements. Satellites can estimate sea surface temperature, and a network of buoys deployed across the tropical Pacific to predict El Niño provides exact measurements, but upwelling, currents, freshwater inflows, and other factors can cause nearshore temperatures to vary from that of the water above, even at depths as meager as 10 meters (33 feet), where they’re diving today. At a subset of sites, one diver—in Rarotonga it’s Zgliczynski—is tasked with mounting thermometers about the size of a bottle of hot sauce, which will log the temperature every 45 minutes until the researchers come back to pick it up in two years. He attaches them to a threaded rod that he hammers into the reef, which also marks the location of the plot Pedersen is photographing.

One diver calibrates the camera, a Nikon D7000 digital SLR, by photographing a 21.5-centimeter by 28-centimeter (8.5-inch by 11-inch) chessboard pattern, printed on underwater paper and affixed to a PVC board. “The angles are never perfect [when photographing underwater], so if you take multiple pictures of a known distance apart, we can adjust for that,” Pedersen explains. Once that’s done, Pedersen starts swimming a meter or two off the ocean floor, making sure to advance slowly enough that each photograph contains about 80 percent overlap with those preceding and following it.

Meanwhile, Zgliczynski and Sandin count fish—not so easy, given that fish move. (Smith teaches a class at UCSD on tallying marine fish and plants, with field trips offshore of Catalina Island, so often this is her job when she’s on an expedition.) They unwind the cables from the dive reels so they know they’re sampling a consistent distance every time, and swim back and forth three times marking every species they see and its approximate size, from which they will later estimate biomass in the area. The fish-counters must take care not to get in the way of the photographer; although the software that creates the models from the images automatically excludes any objects in motion, if they slow Pedersen down the camera’s timer will cause too much of one piece of the plot to be captured, throwing it off.

This work is not without its hazards. In the southern Line Islands last summer, Pedersen was diving a steep slope in 2.5-meter (8-foot) surf when a set of waves that salty types call a “widowmaker” rolled through as she photographed the shallowest section of the reef. One propelled her through a crevice in the reef leading to where the waves were breaking. The camera rig was lost, and Pedersen’s regulator was pulled from her mouth. “I definitely thought I was going to die,” she says, but after about 20 seconds under whitewater she was able to locate her backup regulator and the set passed, allowing her to swim out of the break and to the surface.

After a day of diving, the team’s work isn’t done. First all the gear must be rinsed of corrosive saltwater and left outside to dry, which takes a while in the 85 percent humidity that’s common here during cyclone season. Sandin thumbs through a book, Reef and Shore Fishes of the South Pacific by John E. Randall, to figure out what kind of fish they’ve seen; it turns out species that are supposedly endemic to other islands—such as a type of wrasse, a small cigar-shaped fish—are present in Rarotonga as well. “People won’t believe we saw it except that we have photographs,” Zgliczynski says. “We don’t know if it’s moving farther from the equator [because of climate change], or what. It could be random dispersal through the water column, which is how they maintain genetic diversity.” He’s taking apart a 360-degree camera, images from which will create a virtual-reality experience that can be installed at Scripps’ Birch Aquarium for public viewing. “We can come back and show figures, but that’s boring,” he says. “This gives people an opportunity to be like, ‘Oh, shit, that’s what Millennium Island looks like? There’s sharks everywhere!’”

When he’s done with the VR camera, Zgliczynski needs to record the metadata—logging the latitude and longitude of the dive sites so they can produce maps at the lab in San Diego, and linking data with instruments and locations. It’s coming up on 12 hours since the group left for the docks this morning.

Meanwhile, Pedersen uploads images to a Windows laptop as another computer whirrs away creating a 3D model from the 2,000 or so images gathered during one of yesterday’s dives; a video of the model will be copied onto a thumb drive and delivered to the Cook Islands Ministry of Marine Resources in the morning. The software runs a process called a structure-from-motion algorithm, and can take anywhere from one day to nearly three weeks, depending on the complexity of the site. With seven computers making models simultaneously back at the lab, around 800 have been built so far, with another 600 or 700 in the queue.

Sandin and Smith are exploring the limits of how technology can advance their project. They’d like to develop augmented-reality versions of the models that show how things will progress on a reef under various management practices, based on what they’ve observed at similar reefs with different practices. If people can see an alternate reality and watch how fish grow under various management scenarios, the idea goes, they might be inspired to change what they’re doing.

The scientists hope to be able to deploy underwater autonomous vehicles in place of a human photographer someday, and back in San Diego, engineers at UCSD have experience inventing such machinery. Robots in various stages of development, each roughly the size of a rice cooker and looking very much hand-made, cover a table in the office of Scripps’ Jules Jaffe, who helped design the imaging system used to find the Titanic. He would like to create a swarm of robots that can do Pedersen’s job, freeing her for analytical work. “I thought it’d be cool instead of them swimming around, getting six hours of bottom time per day,” he says.

Up the hill at the Jacobs School of Engineering, computer science and engineering professor Ryan Kastner builds computer systems for oceangoing AUVs. “The amazing thing about Stuart and Jen is they’re really pushing the technology edge,” he says. “I’ve worked a lot with marine scientists and there are some people that say, ‘We’re going to do what works.’ Then there’s a smaller camp that says, ‘Let’s see how we can take advantage of these technological innovations that are coming along,’ and that is the really cool aspect of the 100 Island Challenge.” Within a few years, cheap imaging sensors could be placed into the underwater environment to collect huge amounts of data, perhaps mapping an entire reef instead of just samples to answer bigger scientific questions.

The concerns of Paul Allsworth are more immediate. He’s president and director of internal affairs of Cook Islands’ Koutu Nui, a traditional governmental body like the House of Ariki. The last day of the Rarotonga expedition, the team met with him in a conference room as the roar of the ocean and the crowing of feral roosters could be heard through its slatted windows, open to the breeze. Sandin expressed hope for a future expedition to the outer islands. Allsworth told him that on the outer islands, where he grew up, “The fish are getting smaller, and the catches are getting much, much reduced, and they have to go out further. We don’t know why. So we welcome the technical expertise that your team has.” Pedersen then opened her laptop and showed Allsworth one of the models from the week’s dives.