Ke Chih Hung (left) provided the technology to produce Eucheuma serra to aquaculturist Chen Dinggui free of charge. The seaweed now graces Penghu’s dining tables. (photo by Lin Min-hsuan)
Ke Chih Hung is a technician with the Penghu County Agricultural and Fisheries Bureau. A 2020 recipient of the Examination Yuan’s Civil Service Outstanding Contribution Award, Ke helped create Taiwan’s first manmade marine coral garden. Seeking to restore coral larvae, he developed vibrant coral cultivation barrels that mimic the ecosystem of the South Penghu Marine National Park.
Known as one of “Penghu’s secret dive spots,” Hangwan, in Magong City’s Suogang Borough, isn’t nearly as far off the beaten path as it used to be. While the scenery remains unchanged, visitor numbers climbed from under 30,000 per year prior to 2016 to some 60,000 in 2020, despite the coronavirus pandemic. And the area’s peak tourism season has gotten under way earlier than usual this year, with travelers turning up in May to see Taiwan’s first manmade coral garden.
Wu Zhenfu, who owns diving company LoveOcean and helps build reefs, says that whale sharks and dolphins used to be common at Hangwan, but they now rarely visit. He attributes the change to the severe damage Penghu’s marine habitats have suffered from climate change, marine litter, and wastewater discharge. But Wu also points out that things are improving, noting that the county government’s four-year restoration effort has improved the survival rates of Hangwan’s staghorn coral (Acropora muricata) and Acropora hyacinthus, a table coral. This has increased tropical fish, sea turtle, and sea urchin populations around the reef. He adds that divers often see barracudas, green humphead parrotfish, and moray eels in the area now as well.
Restoring the marine ecosystem
In fact, the Penghu County Agricultural and Fisheries Bureau has been routinely depositing 50 coral-seeded blocks in the sea every year since 2008. But where were they placed? How effective were they? When the county’s Marine Life Propagation Station conducted a survey in 2016 to find out, it discovered that the majority of the blocks had been washed away by ocean currents or otherwise destroyed. The only ones to grow into a reef had been placed in the ocean near Mt. Shetou. This small peninsula across the bay from Magong Harbor had sheltered the blocks from the currents caused by southwest erly monsoon winds. Even so, no fish had taken up residence.
Though Ke Chih Hung was only a clerk back then, he worked up a policy proposal based on the new information. To prevent the triangular blocks from being washed away, they should be assembled into terraced structures that would be more stable on the seabed. Since 2018, the bureau has focused its resources on a 336-square-meter zone (roughly the size of a basketball court) at Hangwan, installing 566 of its triangular modules there over the past three years. These modules have been the key to creating the artificial reef at the heart of the coral garden.
But cultivating coral seedlings is itself no easy task. Ke experienced more than two years of failure before he succeeded in developing his coral cultivation barrels in 2019. His process emulates the marine ecosystem by removing muck from the bottom of the barrels, and then using sea urchins and commercial top shells (a sea snail) to consume planktonic algae, and coral stones to clean the water. At less than NT$10,000 each, the cultivation barrels are inexpensive to build, and yet they have helped restore the area’s Acropora hyacinthus and Acropora muricata populations.
Ke achieved a technological breakthrough that enabled the cultivation of Caulerpa lentillifera and its translucent fruit, known as “sea grapes.” (photo by Lin Min-hsuan)
Caulerpa lentillifera
Ke says that it took teamwork to build the coral garden, noting that they relied heavily on the local diving industry’s help to install the modules and keep the budding corals free of mud and algae. But Ke feels that his greatest achievement as a civil servant has been his cultivation of seaweeds, not his work with coral.
When Ke was tasked with cultivating commercially valuable seaweeds such as Pyropia and Caulerpa lentillifera, he used to go into work at six o’clock every morning to check on their growth.
Seaweeds proved to be challenging to grow, and Ke turned to Hisao Ogawa, a Japanese visiting professor at National Taiwan Ocean University, and the faculty of National Penghu University of Science and Technology, for help. Though all were very generous with their knowledge, Ke remained stalled for more than a year. “For reasons I don’t remember, I ended up buying a really long air hose. When I put it in the cultivation barrel, the Caulerpa lentillifera started to grow.” Chuckling, Ke explains, “The hose created a strong current, which was just what this seaweed needed.” The current enabled the Caulerpa lentillifera to grow to a length of ten centimeters and produce dense clusters of sparkling “sea grapes.”
Ke subsequently transferred his technology to cultivators free of charge, enabling them to grow the seaweed year round instead of only in summer. They now produce steady yields of “sea grapes” that they can sell for as much as NT$2500 per kilogram. “You can enjoy them right here on Penghu. No need to go to Okinawa.”
Ke patented his “strong current” technique, and then extended it to a “seaweed cultivation apparatus” for growing Eucheuma serra, a commercially valuable red seaweed. Basically a barrel with a windmill-like device mounted on the bottom, the apparatus generates a strong and steady current. By keeping the seaweed moving and making it difficult for unwanted algae to establish themselves, the system enables the Eucheuma serra to double in size in a month.
Whereas fishermen along Taiwan’s northeast coast harvest wild Eucheuma serra from March through May, aquaculturist Chen Dinggui now produces steady yields of the seaweed year round at his Baiwankang Recreational Fish Farm using technology that Ke provided free of charge.
“I want to do things that benefit Penghu,” explains Ke Chih Hung. It’s a great place to visit, and he hopes that once the pandemic is over, everyone will come and check it out!
