A Chinese woman was perplexed when she saw that her luggage was causing concern as it passed through an X-ray scanner at Don Mueang airport.
She reached for a red plastic bag after it had passed through the machine, but a young airport security official snatched it and said "No!"
A group of her friends were waiting nearby. They were puzzled too. Some of them wore floral clothes indicating they had been on holidays at the beach.
"You're not allowed to carry this back home," the official insisted. He tried to explain the situation for about a minute, but the woman eventually passed through the security area without being fined or charged and without the red bag.
When the security official opened the plastic bag, a piece of white, dead coral about the size of an outstretched hand was inside. It was still damp with seawater.
That happened two weeks ago, and came amid wider fears that coral bleaching caused by human interaction and warming waters could decimate reefs in Thailand and across the globe.
On June 7, Krabi International Airport said it had seized 171 kilogrammes of coral from tourists in the departure terminal -- in the space of just one month. Over 10 types of corals such as brain, staghorn and hump were found. Even though the removal of coral from the ocean can carry heavy fines and even jail terms, airport officials said most tourists did not know it was illegal. Many said they had taken the coral as a souvenir.
Government marine biologist Nalinee Thongtham, who has monitored a recent surge in severe coral bleaching in Thailand, says tourists behaving badly is just as detrimental to the sensitive organism as global warming.
"Coral bleaching is certainly caused by global warming," said Ms Nalinee, who is based at the Phuket Marine Biological Centre. "But the chance for it to recover relies on human inactivity. Coral's overexposure to tourism and pollution will leave it with only a small chance to survive."
FEELING THE HEAT
The most recent El Nino event, which began around the middle of 2014, has seen sea temperatures rise across much of the planet. Severe damage occurred at one of the seven natural wonders of the world, Australia's 2,300km Great Barrier Reef, where scientists say 35% of coral in its northern and central sections has been destroyed by bleaching.
lost their colours: Examples of coral bleaching off the coast of Thailand, which has been hit by high sea temperatures in recent years.
"For many areas around the globe, the damage from this [El Nino] event has been the worst ever," said Mark Eakin, coordinator of Coral Reef Watch under the National Oceanic and Atmospheric Administration, an American scientific agency.
"Because this event has gone on for so long, about half of the locations stressed by this event have been hit twice already," he told Spectrum. "Some may be hit three times before the event is over."
Bleaching is caused when water is too warm, forcing coral to expel the algae living in their tissues and causing them to turn completely white. When a coral bleaches, it is not dead. Coral can survive a bleaching event, but they are under more stress and are subject to mortality.
Reef Watch's bleaching models, based on satellite images and sea surface temperatures, indicate Thai waters will continue to be unusually warm for the next two months. The worst bleaching is likely to occur in the Gulf of Thailand, but bleaching is likely to continue on Andaman Sea reefs as well.
According to the NOAA, Thailand and Southeast Asia suffered severe bleaching in 1998, 2010, 2015 and this year.
While 1998, 2015 and 2016 were strong El Nino years, 2010 was a mild El Nino, suggesting the regular climate event is not the sole cause of bleaching.
"As we have raised the CO2 concentration in the atmosphere, most of the excess heat has been absorbed by the ocean. That raises the baseline temperature of the ocean, making it easier for smaller climate anomalies to cause mass coral bleaching," Mr Eakin said.
"Thailand and Southeast Asia are likely to see more frequent and severe coral bleaching in years not associated with El Nino."
Since early this year, the Department of Marine and Coastal Resources has recorded high sea temperatures of between 32C and 33C in many coastal areas. The highest temperature for Thai waters this year was recorded on May 11 at 33.85C.
The threshold for coral bleaching is 30.5C, according to the DMCR. Severe bleaching was reported in the Gulf of Thailand in March, with Ma Prao Island in Chumphon the worst affected with up to 80% of the coral bleached.
Bleaching was later reported around Koh Samui, then spread to the Andaman Sea in April affecting more than 50% of coral in Racha Yai, Racha Noi and Mai Ton islands off the Phuket coast, as well as parts of the Phi Phi islands in Krabi and Hat Chao Mai National Park in Trang.
The DMCR found 81 sites had suffered bleaching, 48 of which were classified as critical.
HOPE OF RECOVERY
Despite the US agency's warning of rising sea temperatures over the next two months, Ms Nalinee said the ocean has in fact cooled by one to two degrees recently due to the subsiding of El Nino.
Ms Nalinee has surveyed some diving sites and found colour pigmentation returning to some bleached coral. But this hasn't reassured her that all coral will recover fully.
In 2010, Thailand was hit by its most severe bout of coral bleaching. About 70% of coral in the Andaman Sea, covering 80 square kilometres, was damaged. Between 30% and 95% of the affected coral died.
Ms Nalinee said human activity also plays a major role in the coral's chances of recovering.
Coral growth in areas with intense human activity, especially tourism, is already weak and the problem only worsens when warmer water arrives, she said.
She noted a "unique" snorkelling spot off Phangnga's Koh Khai Island, where visitors could see large plains of staghorn coral in 2008. Six years after the 2010 bleaching event, only 20% of the coral survives.
Koh Khai Island, covering an area of only about 10 rai, has been intensely exploited by tourism. More than 40 tourist boats flock there each day during peak seasons, throwing their anchors onto the brittle reef below.
Tourists feed fish and pollute the once pristine waters. Some step on the coral, or collect pieces from the sea floor to take home as souvenirs. Tour guides rarely give instructions on not damaging the coral.
Similar tales of coral struggling to recover after the 2010 bleaching were reported at other popular tourist islands, including Similan and Surin islands, and Phuket and Phi Phi islands, which have long suffered problems with tourist wastewater being discharged directly into the sea.
Damage to coral from bleaching, which was aggravated by human activity, was worse than the harm caused to Thailand's reefs by the 2004 tsunami, according to a DMCR report.
"Tourism is the main revenue source for the Thai economy. But without good management of that tourism, coral will likely not survive," said Ms Nalinee.
The situation prompted some marine experts and environmentalists to call for the shutdown of several at-risk islands, as well as caps on tourist numbers.
TOURISM FIRST
More than 28 million foreign tourists visited Thailand last year. That number is expected to jump to 45 million in 2020 and 67 million in 2030, according to the Ministry of Tourism and Sports.
Slow recovery: Department of Marine and Coastal Resources experts look for growth after the bleaching in 2010, when many of the country's once-colourful reefs were damaged.
More than half of the visitors come for "ocean tourism", raising concern about the ability of coral to survive the increased strain.
Every year, the Department of National Parks, Wildlife and Plant Conservation (DNP) closes down islands and coral reefs far off the coast during the monsoon season to allow the areas time to recover.
But reefs near the coast, such as off Phi Phi Island, remain open year-round.
"In fact, Thailand has never announced a shutdown of any bleaching sites," said Thon Thamrongnawasawat, a marine expert from Kasetsart University's Fisheries faculty.
"There's concern from local people who depend solely on tourism for their living. It's something that we have to think a lot about before taking action. Tourism will have to continue with strong measures to prevent damage to nature."
Only about 1% of coral surrounding Phi Phi Island recovered after the 2010 bleaching, which Mr Thon said was an indication of the need to better manage tourism activities.
He launched the "Phi Phi Model" as a way to involve local tour operators in the protection of marine wildlife, which started by campaigning to stop selling sharks and parrot fish as meals for tourists.
Two months ago, Mr Thon pushed the government to indefinitely shut down coral sites at Tachai Island off Phangnga and Koh Young off Phi Phi Island, where coral has been seriously damaged by tourist activities. Both areas have also been affected by recent bleaching.
The government's move only came after reaching an agreement with local tour operators.
Mr Thon said another snorkelling site near Thale Waek and four dive sites near Phi Phi Island, including Whaleshark Wall, will be closed to help the coral recover.
Another major problem is the lack of marine scientists at the DNP, which manages marine national parks around the country. Mr Thon said there is only one marine scientist working for the DNP, while at least 20 were needed to manage marine tourism sites alone.
In response to the coral bleaching, the DNP plans to close down more than 10 dive spots, but it has yet to specify where and when.
Last month, the DMCR issued an urgent regulation to restrict tourist activities in coral bleaching areas including Koh Man Nai off the Rayong coast, Koh Khai in Chumphon, Racha Yai Island, Mai Ton Island and Laem Panwa in Phuket.
Tourists can visit the areas but are prohibited from catching animals, feeding fish and picking up and stepping on coral.
Tour operators were instructed not to throw anchors into coral areas or dump garbage and wastewater into the ocean.
A Chinese tourist, 45, was the first to be charged under this new regulation after officials found he had fed fish in Phangnga to attract them for a photo opportunity.
He faced a maximum penalty of a year in jail or a 100,000 baht fine or both. Bail was set at 100,000 baht.
But he was eventually let off with a 2,000 baht fine, which the presiding judge slashed in half due to the defendant's guilty plea.
'GLOBAL EMERGENCY'
Ove Hoegh-Guldberg, director of the Global Change Institute at the University of Queensland, which monitors global bleaching, said stress from tourism, pollution and overfishing was not the only factor that affects coral recovery.
"Unfortunately, mass coral bleaching events like we are currently experiencing are predicted to become almost annual events within the next 20 years unless we deal with the problem of fossil fuels," he said.
"We must have a renewable energy revolution to reduce the carbon dioxide and other greenhouse gases building up in the atmosphere."
Unless both climate change and local stresses are addressed, Mr Hoegh-Guldberg believes those working in ocean-related tourism industries will not have careers within 20 years.
The current spate of very warm weather in the Pacific and Indian oceans suggests a lot of coral will die over the next couple of months. In this case, he said, it will take between 10 and 20 years for coral populations to grow back.
This will have serious consequences for countries like Thailand which depend on people coming to see the beautiful coral, he said, as well as reducing food sources for millions of people throughout Southeast Asia as reefs become sick and die.
"This is now a global emergency, and must be treated as such by all governments on the planet," he said. n
Coral reefs in the southwest are at risk of bleaching over the next two months, in both the Gulf of Thailand and the Andaman Sea. This is the forecast as of Monday.
Coming in numbers: Tourists visit Koh Khai Island, where large plains of staghorn coral could once be seen. Since the 2010 bleaching, only 20% of the coral has survived.
Lead-in: Koh Khai Island.
Lost their colours: Examples of coral bleaching off the coast of Thailand, which has been hit by high sea temperatures in recent years.