Tensions are rising between South Korea and China over the rapid expansion of Chinese fish farming structures in the disputed Yellow Sea, with lawmakers and experts warning that the installations could signal a broader push by Beijing to assert territorial control through so-called “grey zone” tactics. The Financial Times reports that the controversy has emerged as the latest flashpoint in China’s contentious maritime posture across East Asia.
In a rare bipartisan move, South Korea’s parliament convened a special hearing last month to condemn the steel fish farming installations, which have been erected by Chinese companies in the waters between the Korean peninsula and China. While Beijing maintains that the structures are purely for aquaculture and comply with international norms, officials in Seoul argue they are part of a subtle campaign to alter the regional status quo.
“This is a clandestine tactic to claim our waters inch by inch,” said Jaewoo Choo, head of the China Research Center at the Korea Research Institute for National Security. He warned that the move also appeared designed to “restrict the operations of the US-South Korea alliance.”
South Korean lawmaker Na Kyung-won, from the ruling conservative People Power party, went further, accusing China of employing “gangster tactics” to dominate regional seas. “A firm and stern response is needed to address China’s unfair attempts to change the status quo,” she posted on social media.
The controversy centers on fish farms constructed within the “provisional measures zone” (PMZ), a disputed area of overlapping exclusive economic zones. The first major structure, Shenlan 1, was built in 2018 by China’s Wanzefeng Group. A second, Shenlan 2, followed last year through a joint venture with the state-owned Shandong Marine Group — despite official protests from Seoul.
According to South Korean media, confirmed by the Financial Times, a Korean marine research vessel dispatched to investigate last month was forced to retreat after a tense standoff. Beijing, meanwhile, has sought to play down the dispute, insisting that communication channels remain open and that the structures do not breach the countries’ fishing agreements.
However, analysts warn that these developments are consistent with China’s broader strategy of establishing a physical presence in contested waters as a foundation for future territorial claims. “They use subsidies and infrastructure to normalize their presence,” said a senior Philippine official, drawing parallels to confrontations in the South China Sea.
Chinese observers have echoed this view. A popular blogger recently wrote: “On the surface, we are building ordinary fish farms. But in fact, this is a smart move to increase our actual control in these disputed waters.”
Nam Sung-wook, professor at Korea University, cautioned that an expanding chain of Chinese installations could impede South Korean and U.S. naval movements, particularly in a potential conflict in the Taiwan Strait. “If any country doesn’t respond to such territorial issues immediately, it becomes a fait accompli,” he said.
South Korea’s foreign ministry has since reaffirmed its maritime rights in the Yellow Sea, vowing an “active response” moving forward.
The tensions come at a delicate diplomatic moment. As the Financial Times notes, China is attempting to warm relations with South Korea and Japan, even as Donald Trump’s renewed trade war escalates. Last month, China hosted the first trilateral trade meeting with the two U.S. allies in six years, though efforts to coordinate a joint response to Trump’s sweeping “liberation day” tariffs fell flat.
Ahead of Thursday’s scheduled trade talks with the Trump administration, South Korea’s acting president Han Duck-soo told the Financial Times that Seoul would avoid retaliatory measures and was open to discussing non-tariff adjustments, citing the country’s historic ties to the United States.
Yet with maritime flashpoints multiplying, Patricia Kim of the Brookings Institution warned that China’s regional assertiveness may be undercutting its diplomatic aims. “This is a textbook example of how China’s aggressive maritime policies have alienated many of its neighbours,” she said. “Even as Beijing seeks to cultivate friendly partners, its assertive actions undercut its efforts.”
