BEIJING—In a video, a man wearing a cap embroidered with “China” takes a selfie with his smartphone while walking through one of the largest fish markets in the world in Tokyo.

The man apparently wanted to show that the safety of seafood is not being questioned in Japan and not taken as a concern by capturing large crowds of customers flocking to the Toyosu market.

Chinese authorities have fiercely opposed the discharge of treated wastewater into the Pacific Ocean from the Fukushima No. 1 nuclear power plant, which started in August last year.

They call the wastewater “nuclear contaminated water” and claim that it is unsafe.

“I came here to ask Japanese about their thoughts on marine products,” the man said in the clip posted on a video-sharing platform in April. “But I am now wondering if I still need to do that after seeing the long line of people waiting to buy seafood.”

Japanese fishers are not the only casualties of the Chinese government’s total ban on seafood imports from Japan imposed immediately after the start of the discharges.

Chinese in the fisheries industry along with this man have also taken a hit.

Consumers in China increasingly shun marine products even if they come from home waters, adding to the fisheries’ economic misery.

Fishers blame social media posts, for reputational damage to their products by repeatedly stating that marine life and human health have been put at “serious risk” by the releases.

The man who appeared at the Toyosu market is believed to be cultivating sea cucumbers in China. These marine animals are traded as a high-end food product and farmed in coastal regions.

He has also posted multiple videos to tout the safety of sea cucumbers.

Another Chinese man who said he farms flounders in the northeastern region also waged a similar campaign.

He posted a series of videos in late July in which he sipped water from, swam in and ate fish from his aquaculture pond, to convince consumers of the safety of marine products.

While he said he would sue Tokyo Electric Power Co., operator of the Fukushima plant, for damage from the water releases, he refuted widespread assertions on social media that seafood is not safe to eat.

“Is there any evidence to prove it?” he asked in the video. “How about the results of official inspections?”

When Beijing expanded the ban on seafood imports to a total ban in opposition to the discharges, state broadcaster China Central Television extensively covered the issue day after day, showing a wave of protests against the discharges in Japan.

Online media outlets, too, scrambled to toe the official line, likening eating seafood to a reckless act.

Perhaps most damaging to the Chinese fisheries industry was a video simulating the contaminated wastewater reaching the Chinese coast some 240 days after the release.

The video was widely shared. Leading news outlets also covered the simulation, which was reportedly made by a research team affiliated with Tsinghua University, China’s top-tier institution, known for its advanced scientific research.

But the man who visited the Toyosu market sought more of an explanation.

In one of his videos, he called the university to inquire about the team’s findings.

It was apparently what many in the fisheries wanted. The video attracted comments from his colleagues who expressed their appreciation to the man for making an effort to convey their thought.

The man who cultivates flounders, too, made an impassioned plea for the Tsinghua scientists to provide a detailed explanation to the fisheries in his video.

The Asahi Shimbun contacted the university’s research team to request an interview, but no reply was given by Aug. 5.

The support to these individuals’ actions reflects the fisheries industry’s resentment against the Chinese government for underscoring the risks of the wastewater without providing concrete evidence to back its assertions.

The perceived risks led to Chinese consumers avoiding seafood as media outlets continued reporting based on the government’s stance.

There was a flurry of panic buying of salt in China after the release began over concerns that sea salt could be contaminated.

At one of the largest fish markets in Beijing, many vendors lamented that the forecasts of the contaminated water washing ashore on the Chinese coast have contributed to their declining business.

“Trade is stagnant this year, worse than during the COVID-19 pandemic,” one shop owner said, adding the negative publicity from the water releases made the situation even worse.

A 52-year-old woman selling live lobsters and abalone noted a shift in consumers’ seafood choices.

“An increasing number of shoppers began buying only freshwater fish, avoiding saltwater fish, after the polluted water is said to have reached the Chinese shores in April,” she said. “The best solution would be for Japan to halt the discharges. But it would be a big help if an authoritative expert in China reassures the public of the safety of seafood.”

By the middle of July, TEPCO had conducted seven rounds of the discharges, totaling about 54,000 tons. The company continuously monitors tritium levels in the ocean close to the plant.

The wastewater contains tritium, a radioactive substance that is technically difficult to remove even after being treated by the filtration system called ALPS, or the advanced liquid processing system. Before the release, the water will be diluted with massive amounts of seawater.

TEPCO has reported that there has been no change in tritium levels.

The Chinese Ministry of Ecology and Environment acknowledged no abnormality in levels of radiation in China’s neighboring waters in 2023 in a report on the marine environment released in May.

But Beijing still refused to budge on the seafood ban.

Talks have been under way between the two governments as China calls for the creation of an international surveillance mechanism by stakeholder nations to independently conduct long-term testing of seawater to monitor radiation levels.