Japan's irresponsible release of nuclear-contaminated water from the destroyed Fukushima power plant is already changing the sea, as the owner of the plant detected record-high amount of radioactive substance in the nearby sea area.

The amount of radioactive tritium reached 10 becquerel (Bq) per liter, according to the measurement result released by Tokyo Electric Power Company (TEPCO) on Friday.

This amount is the detectable minimum and should be considered as the consequence of the water release, TEPCO told Japan's Kyoto News Agency.

The amount has never been so high in the past five years, TEPCO said, and has been within the range of 0.4 to 2.8 Bq per liter.

TEPCO sampled water from 10 locations near the destroyed nuclear power plant on Thursday. Only one sample has such amount of tritium.

However, water and fish sampled by Japan's Ministry of the Environment and Fukushima local authorities didn't have enough tritium to reach the detectable minimum, Kyoto reported.

The long-term trouble

Tritium is not the only radioactive substance that can threaten people's health. In fact, initial analysis from China showed that there are more than 60 kinds of radioactive elements in Fukushima's contaminated water, some of which take centuries to decay and cannot be filtered with current technology.

These radioactive substances will follow ocean currents and spread to the whole world, as the release of Fukushima water will likely take decades to complete, changing the ocean forever.

What's worse, there is no third-party monitoring mechanism on TEPCO's water filtering system. If it stops working, we will have to depend on indirect measures to know for sure.

China said it has been monitoring the radioactivity of sea water near Fukushima with advanced technology like satellite remove sensing, and will timely alert the world if things go sideways.

'Alarming numbers'

Japan's release of contaminated water is opposed by people in and outside of the country.

People's interest in Japanese food is dropping in China's Hong Kong, as the business of Japanese restaurants witnessed a huge drop since the announcement of the water release.

"After news of the contaminated water release around June, business for Japanese restaurants immediately dropped 10 to 20 percent," said Martin Chan, one of the directors of the Hong Kong Federation of Restaurants and Related Trades. "And then over the past month or two, it dropped further to around 40 percent or more."

Chan cautioned that the numbers are "quite alarming" and beyond the federation's expectations, as local people weight food's safety above its variety or price.

South Korea is also affected. A news report from China Media Group showed that the price of groupers has dropped from 30,000 won ($23) per kilogram to less than 20,000.

The South Korean government is planning to pay 57.6 billion won ($44 million) in 2024 to measure the radioactivity of sea water and seafood.

A local environment group in South Korea published a poll result on Friday showing that more than 70 percent of respondents oppose the release of the nuclear-contaminated water. About 78 percent of the 1,000 respondents aged 18 and above said their government is in fact supporting the release, while the right choice is to stop the import of Japanese seafood like what China did.