'Gimflation' pushes firms to grow seaweed on land

As climate change pushes up sea temperatures and squeezes harvests, Korea’s beloved dried seaweed, known as 'gim,' is getting more expensive — and food companies are betting that growing it on land could steady supply and lower prices.

Dried seaweed is displayed at a supermarket in Seoul on Feb. 2. [YONHAP]

As climate change pushes up sea temperatures and squeezes harvests, Korea’s beloved dried seaweed, known as gim, is getting more expensive — and food companies are betting that growing it on land could steady supply and lower prices.

This method allows farmers to grow gim year-round in controlled indoor facilities rather than rely on ocean conditions. Industry sources said that the land-based farming technology needed for this method has entered the pilot stage of development, with plans for commercialization.

The average retail price of gim stood at 1,403 won ($1) per 10 sheets, more than 140 won per sheet, on Thursday, according to the Korea Agro-Fisheries & Food Trade Corporation.

At the start of 2024, one sheet cost approximately 100 won, meaning that prices have risen by 40 to 50 percent in two years, as exports increased while supply failed to keep pace.

Prices exceeded 1,500 won per 10 sheets in late January for the first time on record.

Laver, the seaweed used to make gim, grows best in seawater at temperatures of 10 degrees Celsius (50 degrees Fahrenheit). While laver spores form naturally in the ocean, farmers do not rely on nature alone and instead grow the spores themselves in controlled conditions before attaching them to nets.

Fishermen sort laver after auctioning seaweed harvested from farms near the Nakdong River in Busan on Dec. 27, 2022. [YONHAP]

When ocean temperatures drop in October and November, farmers place the seeded nets in the ocean. About 20 days later, they harvest the seaweed and repeat the cycle several times through May.

Climate change, however, has shortened that growing season.

Warmer autumn waters have reduced the number of suitable cultivation days and lowered output. Last year, sea temperatures in the Yellow Sea and South Sea remained close to 25 degrees Celsius until early October.

“Farmers already use most coastal areas suitable for laver cultivation, so expanding farming sites is not easy,” said Kim Jang-kyun, a professor in the department of marine science at Incheon National University.

Farmers therefore have to explore land-based alternatives to ensure stable supplies and prices.

Although no company has yet brought land-grown laver to market, Pulmuone and Daesang have invested in related research and development (R&D) for three to five years.

Dried seaweed is displayed at a supermarket in Seoul on Feb. 2. [YONHAP]

The two companies were selected last year for a government-led R&D project that will provide them with 35 billion won ($24 million) in funding through 2029.

Land-based farming recreates ocean-like conditions, including temperature and salinity, in indoor facilities or large tanks.

According to Pulmuone and Daesang, both have successfully produced fresh land-grown laver to a size suitable for sale and are now working to improve the technology for consistent quality and large-scale production.

“The taste of land-grown laver does not differ significantly from conventional sea-farmed laver,” a Pulmuone representative said. “Since we can create ideal growing conditions on land, the seaweed may contain more protein, which could enhance its taste.”

Opposition from traditional sea farmers remains a key hurdle, but Pulmuone and Daesang said they plan to share the technology with the farmers to promote coexistence and gradually expand land-based cultivation.

“If land-based farming enables large-scale production, it could expand export opportunities but still operate alongside ocean farming,” Prof. Kim said.

This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom. BY LIM SUN-YOUNG [paik.jihwan@joongang.co.kr]