Home GRASP GRASP/Japan The color of climate change in Japan's Yaeyama archipelago

The color of climate change in Japan's Yaeyama archipelago


Depleting reefs may profoundly reshape Ishigaki Island’s tourism industry.
Viewed from a satellite, Japan’s southern Yaeyama archipelago is a splatter of green blobs ringed in turquoise. Closer to Earth, those encircling lagoons take on more complex shades of blue, often streaked with white lines made by dive boats, cruise ships, rusting inter-island ferries and, more recently, the armed vessels of Japan’s Maritime Self-Defense Force.
Beneath liquid trails of tourism, transportation and regional tension are the kaleidoscopic colors of Japan’s largest and richest coral reefs. Down here, changes mirror the turbulence on the surface, as reefs grow and shrink, and aquatic species migrate in and out each season. These enduring oscillations are expected, but a newer change is pressing itself, sharply, into the lives of those connected to these islands: The colors are leaving. And “leaving” is the right word: Staring through the tempered glass of a scuba mask, what we see when we look at the color of coral is living tissue, the soft biomatter of a plant-animal slowly building a calcium carbonate skeleton. As sea-surface temperatures rise well beyond the average (and for longer periods) in summer, the plant half of the relationship — single-celled algae called zooxanthellae — leaves and, without a source of energy, the coral animal turns bone white. If the algae don’t return when waters cool, coral eventually dies, its skeleton decays and an entire reef can collapse.
In 1998, Ishigaki and other islands in the Yaeyama archipelago were hit by the first global coral bleaching event. Some parts of the reefs collapsed as a result. Bleaching events have returned in parts of the globe every three to five years since then, but in 2016 and 2017, particularly high sea-surface temperatures appeared back-to-back for the first time: Roughly 90 percent of Yaeyama’s coral was bleached in 2016 and, according to the Environment Ministry, more than 70 percent of the largest reef, the Sekisei Lagoon, died. In January, the ministry reported that roughly 49 percent of the remaining coral was bleached in 2017; we still don’t have accurate figures on how much has died. None of this is normal.
Here are the stories of people in the Yaeyama archipelago, particularly those on the main island of Ishigaki, whose lives are affected by single-celled zooxanthellae and climate change — two interrelated factors, microscopic and planet-sized, that determine the color of coral. The quantitative story of reef decay has been well told, even on these remote islands, but there are few stories that explore how changes to the Yaeyama reefs are affecting people, including reef scientists, hotel directors, guesthouse owners, government employees, tour guides and divers such as Harvey Tiew Lee Leong and his pregnant wife, Mikiko Ando Tiew.
Yonehara Reef lies in a coral-rich transparent lagoon on Ishigaki Island.| COURTESY OF DIVING SCHOOL UMICOZA
Leong and Tiew run Diving School Umicoza in a patch of jungle in northern Ishigaki, between a shrimp farm and cow paddocks, and looking out to an azure lagoon. Umicoza is one of roughly 200 dive schools/shops on Ishigaki, and specializes in excursions to the island’s northern reefs. During summer months, instructors will spend hours each day swimming over coral, alongside tropical fish, sea snakes and manta rays.
“When I first came here… lots of coral,” Leong says. He slides open the door to the garden at the center of school, leading the way to a view of the lagoon below, his tanned and tattooed arms barely showing beneath the black sleeves of a hooded sweatshirt. The coral now? “Dead,” he says. We both know the answer is an exaggeration, but not by much — over the past 20 years, significant amounts of the reef (some reports suggest more than half) have collapsed.
The waves break hard against the reef edge below, and clouds hang heavy, spitting into a cool northerly wind. The air smells like wet foliage. Droplets run down umbrella-sized taro leaves into soggy earth. Cane and cattle stretch around the headland to the south, leading to farmland where the SDF is building missile batteries to defend the island from invasion. Also worrying to locals is the invasion of tourists, whose numbers increase each year — in 2017,1.3 million domestic and foreign visitors came to this island of almost 50,000 people and, since Ishigaki was named the world’s No. 1 trending travel destination by TripAdvisor in January, more are expected.
Geopolitical tensions and out-of-control tourism worry Leong and Tiew, but there are more immediate concerns troubling them today.
“We just hope the typhoons come (this year),” Leong says. “Each time the typhoon comes then the ocean temperature will go down a bit.”
Certain dive locations have been completely changed over the past two years due to mass-bleaching events. Anything that brings down the water temperature — even destructive typhoons — is desirable.
“Maybe in another 30 to 50 years we still can see something,” Leong says, thinking about how the reef might look to his children when they are older. “I hope coral is growing, I hope the next generation will also see them.”
Tiew will give birth to their second child later this year.
Umicoza does what it can to mitigate stress on the coral by limiting the number of dives it takes each day, and ensuring minimal damage occurs when they drop anchor. Tiew says that some unregistered dive shops, particularly those that have flourished as tourism booms, are not so careful. Umicoza also takes customers to see the changes to the reef: One photo from a group dive in 2017 shows a single blue branching coral amid the brown rubble of a collapsed reef. But there is only so much that can be done.

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