When life gives you green sea lettuce: Jeju copes with beach bane
by KoreaJoongAngDaily
Masses of green sea lettuce drift between the waves at Hamdeok Beach in Jeju on June 24. [JOONGANG ILBO]
Jeju’s emerald waters are turning murky as early, heavy blooming sea lettuce and brown algae blanket its beaches, disrupting tourism and straining coastal ecosystems.
The swarm of vegetation was more than visible at Hamdeok Beach in Jeju City on the morning of June 24, the view sabotaged by the green seaweed floating between the waves instead of the clear waters the beach is typically known for.
As the beach officially opened for the summer season, a large number of people visited, but noticeably fewer entered the water compared to previous years.
“I was shocked by how much seaweed was floating in the emerald-colored water,” a 24-year-old tourist surnamed Kim from Seoul said. “I didn’t want it getting in my mouth while swimming, and it was chillier than I expected, so I gave up on going in.”
Nearby at Sinheung-ri Beach, green algae had accumulated across a 40-meter (131-foot) stretch of white sand, and swarms of gnats hovered over the mounds of seaweed.
Green sea lettuce also covered the rocky shoreline and breakwaters in Iho-dong, on the western coast of Jeju City, on June 23. Although these are not officially designated beaches, they are popular spots for both tourists and locals during the summer.
People visit Hamdeok Beach in Jeju on June 24, as green sea lettuce drifts between the waves. [JOONGANG ILBO]
"We are stepping up efforts to remove marine algae from the beaches and coastlines that opened early this year," the Jeju provincial government said.
Designated beaches indeed appeared mostly cleared of sea lettuce and other algae as of June 24.
Jeju has deployed 163 coastal environment workers, while Seogwipo has dispatched 115 to clean local shorelines from March 10 to Oct. 31.
Between 2021 and early May this year, Jeju collected 24,885 tons of green sea lettuce and 11,611 tons of Sargassum horneri, a type of floating brown algae.
Green sea lettuce typically blooms during the rainy season. Experts point to rising surface water temperatures and a freshwater influx from underground aquifers as key causes. Nutrients like phosphates and nitrates from nearby fish farms also create favorable conditions for algae growth.
A man wades through green sea lettuce that has washed ashore near a port in Iho-dong, western Jeju, on June 23. [JOONGANG ILBO]
Another algae species plaguing Jeju’s waters is Sargassum horneri, which appeared earlier than usual in early spring this year, frustrating tourists.
The Ministry of Oceans and Fisheries designated it a harmful marine organism in 2023.
The algae grow up to 5 meters along the southern coast of China before drifting north with the Kuroshio Current to Korea’s southwest and Jeju waters.
The algae cling to aquaculture nets and facilities, disrupting fishing activities and posing safety risks to boats and tourists. Unlike edible native varieties used in Jeju dishes like momguk, or gulfweed soup, Sargassum horneri remains tough even when boiled and is therefore not consumed.
With no effective method to eliminate the algae besides manual removal, Jeju currently buries or composts the collected nuisance. The province also plans to launch pilot programs using the algae in cosmetics.
Tests found that green sea lettuce contains olban and polyphenols with anti-inflammatory and antioxidant properties that help brighten skin. Sargassum horneri contains fucoidan and polyphenols, which are known for their moisturizing and antioxidant effects.
Green sea lettuce rots on the pebble shore off Iho-dong, western Jeju, on the morning of June 24. [JOONGANG ILBO]
Jeju plans to supply the collected algae to local bio companies, which will dry and extract it for use in cosmetic products like shampoo and soap.
Jeju, meanwhile, opened 10 beaches early this year on June 24 in response to unusually warm weather: Geumneung, Hyeopjae, Gwakji, Hamdeok, Iho Tewoo, Woljeong, Samyang, Gimnyeong, Hwasun Geummorae and Pyoseon.
The province will open Sinyang Seopji Beach on June 26 and Jungmun Beach on June 30. The regional government has deployed 228 public and private safety personnel and 529 lifeguards from the 119 citizen rescue corps to major beaches.
“Jeju beaches will be managed under the principles of cleanliness, fairness and safety,” said Oh Sang-pil, director of Jeju’s Oceans and Fisheries Bureau. “Every day, all beaches will hold a daily 30-minute ‘plogging time’ at 3 p.m., where visitors can voluntarily clean the beach and reflect on the importance of the ocean and the planet.”
Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.
Reference Written by CHOI CHOONG-IL [paik.jihwan@joongang.co.kr] Provided by Korea JoongAng Daily
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