Why Hyundai Motor and LG Electronics are funding underwater forests

Kelp and ecklonia transplants restore fish habitats and spawning grounds — and absorb CO2

Hanwha Ocean, LG Electronics and Korea Electric Power join Hyundai Motor, Hyosung and Posco in corporate push

375 sq km created through last year, with target of 540 sq km by 2030

A dense underwater forest created using ecklonia thrives on the seafloor. [Korea Fisheries Resources Agency]

Just as forests on land are defined by their trees, the ocean has its own equivalent: kelp and ecklonia. For fish, these seaweed beds are feeding grounds, spawning sites and shelter. For people, they are vast underwater forests that absorb carbon dioxide, one of the main drivers of global warming.

Some of South Korea's biggest companies — spanning automakers, electronics manufacturers, steelmakers and shipbuilders — are now voluntarily funding the creation of these "sea forests." Hanwha Ocean, LG Electronics and Korea Electric Power joined the effort this year, following Hyundai Motor Company, Hyosung Group and Posco. Companies including Lotte Chilsung, Lotte Mart, LX Pantos, Kolon Industries and Korea Zinc have also pitched in to tend forests that are already established.

Fish eggs cling to seaweed in an underwater forest as a school of fish swims nearby. [Korea Fisheries Resources Agency]

Why are these companies pouring money into planting kelp and ecklonia on the ocean floor?

According to the Ministry of Oceans and Fisheries, sea forests are the flagship marine ecosystem restoration project for reviving stretches of ocean laid bare by "barrens" — a phenomenon in which seaweed disappears and the seafloor turns barren. Workers transplant seaweed species such as kelp and ecklonia onto rocks and other surfaces, improve the surrounding environment so the plants can take firm hold, and remove sea urchins and other grazing animals that feed on the seaweed.

Schools of fish swim through seaweed in an underwater forest created off Jangil-ri in Pohang, North Gyeongsang Province. [Korea Fisheries Resources Agency]

The first reason sea forests matter so much is that they give fish back their homes and food. When kelp and ecklonia grow thick enough to form a forest, they supply abundant food for marine life and create spawning and habitat areas where fish can breed and live safely. Stretches of ocean that had lost their function as seaweed disappeared are restored to living spaces for marine organisms.

Before-and-after views of a sea forest site and low-cost cultivation techniques. Artificial reef structures, attachment panels, seedling pouches and underwater longlines are used to establish a base for seaweed growth. [Ministry of Oceans and Fisheries]

The ecological turnaround that sea forests produce is also measurable. A comparison of 16 seaweed sea forest sites completed last year — assessed at the one-year and four-year marks — found that the barrens phenomenon had declined by 54.7 percent.

A rudderfish swims around an underwater forest created using ecklonia. [Korea Fisheries Resources Agency]

Seaweed biomass rose 138.5 percent, from 322 grams per square meter to 768 grams, while the species diversity index climbed 64.1 percent, from 1.84 to 3.02. The index measures how evenly a variety of organisms coexist — the higher the figure, the more stable the ecosystem. The ministry noted that Chesapeake Bay in the United States, widely cited as a successful ecological restoration case, maintains a species diversity index above 3.0.

Another major benefit for people is carbon absorption. Like trees on land, seaweed underwater takes in carbon dioxide and produces oxygen.

The scale of the effort is far from small. Since the government launched the sea forest program in earnest in 2009 through last year, a cumulative total of 375.4 square kilometers of sea forest has been created nationwide — roughly 62 percent of Seoul's total area of 605.2 square kilometers.

The ministry estimates that sea forests of that size absorb about 126,000 metric tons of carbon dioxide annually, equivalent to the emissions of roughly 52,000 cars. With 37.9 square kilometers to be added this year, the cumulative area will reach 413.3 square kilometers, or about 68 percent of Seoul's area.

Sea forest development status and targets [Ministry of Oceans and Fisheries]

The government's 2030 target is 540 square kilometers — nearly 89.2 percent of Seoul's area. If that goal is met, the ministry projects annual carbon absorption will rise to 182,000 metric tons, equivalent to roughly 75,000 cars.

As the ecological and carbon-absorption value of sea forests grows, companies are stepping up their involvement in the program.

For businesses, participating in sea forest development is a direct way to advance environmental, social and governance management, respond to the climate crisis and help protect marine ecosystems. Companies can also go beyond simple donations and take an active role in creating and maintaining sea forests in specific sea zones.

A diver surveys an underwater forest created using ecklonia and sea mustard. [Korea Fisheries Resources Agency]

The government has opened the door to corporate participation. The sea forest program, which began in 2009, introduced a cost-sharing model with private companies in 2024. Under the arrangement, the government and a corporate partner each cover half the cost — a 50-50 matching structure. The baseline investment for a single project site is 1.3 billion won ($939,000) over four years, with the government and the company each contributing 650 million won. Of that total, 1 billion won is invested in the first year, followed by 100 million won annually for the next three years. Once development is complete, the site is evaluated and handed over to the local government for ongoing maintenance.

Corporate sea forest development partnerships [Ministry of Oceans and Fisheries]

The first companies to join the public-private sea forest program were Hyundai Motor, Hyosung Group and Posco. Together they are investing a combined 3.65 billion won from 2024 to 2027, matched by an equal government contribution, for a total of 7.3 billion won directed at four sea forest sites in Ulsan, Wando-gun in South Jeolla Province and Pohang in North Gyeongsang Province.

Specifically, Hyundai Motor is investing 2 billion won in Jujeon-dong, Dong-gu, Ulsan and Dangsa-dong, Buk-gu, Ulsan, while Hyosung Group is putting 650 million won into Donggo-ri in Wando-gun, South Jeolla Province. Posco is committing 1 billion won to Gupyeong 1-ri and Mopo-ri in Pohang, North Gyeongsang Province. Of that amount, 449 million won will take the form of in-kind support — the manufacture and installation of artificial reef structures for which Posco holds the patent.

Corporate participation is growing. This year, Hanwha Ocean is investing 650 million won in Oepo-ri, Geoje, South Gyeongsang Province; LG Electronics is putting 650 million won into Deongmyeong-ri, Goseong-gun, South Gyeongsang Province; and Korea Electric Power is committing 650 million won to Gungsi Island in Taean-gun, South Chungcheong Province — each running through 2029. The three new projects together will create 4.64 square kilometers of sea forest.

Workers carry out maintenance at a sea forest site, including supplementary seaweed transplanting, removal of grazing animals and waste collection. [Ministry of Oceans and Fisheries]

Researchers survey the extent of ocean barrens using natural seaweed colony protection, climate-adaptive seaweed exploration and hyperspectral aerial imaging. [Ministry of Oceans and Fisheries]

Tending a forest consistently matters just as much as planting it in the first place — and sea forests are no different. That is why corporate involvement is expanding beyond new development into long-term maintenance.

Hyosung Group has funded maintenance of sea forests in Dade and Dapo, Geoje, South Gyeongsang Province; Lotte Mart has supported a site on Jangja Island in Gunsan, North Jeolla Province; and Lotte Chilsung has contributed to upkeep in Uihang-ri, Taean, South Chungcheong Province. Korea Electric Power, LX Pantos, Kolon Industries, Busan New Port and Korea Zinc have also joined sea forest maintenance efforts in their respective regions. The government plans to expand a model linking sea forest development and maintenance around anchor companies in each coastal zone.

Corporate sea forest maintenance support [Ministry of Oceans and Fisheries]

The sea forests created through corporate investment pay dividends in the form of marine ecosystem restoration and carbon absorption. Companies advance their ESG commitments while contributing to climate action and biodiversity conservation, and the ocean reclaims the space that seaweed and marine life need to thrive. The forests that result serve as feeding grounds and spawning habitat for fish, and as sinks for carbon dioxide.

Returning kelp and ecklonia to the seafloor is, in essence, the ocean equivalent of planting trees on land. That is why companies are spending money to build a "blue forest" beneath the waves — and the returns, in the form of restored marine ecosystems and absorbed carbon, come back to all of us.

adastra@heraldcorp.com