Authorities in China have levied fines worth more than 1 billion yuan ($137 million) on Chinese companies for fishing illegally in international waters since 2016, a white paper said on Tuesday.

The penalties were part of an intensified push by the world's leading seafood exporter to promote a more sustainable approach to deep-sea fishing as it looks to blue waters to meet food security needs, said the report compiled by the State Council Information Office.

The report, titled "Development of China's Deep-Sea Fishing Industry", said it was aimed at introducing China's stance, principles and approach on deep-sea fishing, and serves as a window to China's expertise in managing fishing operations.

A total of 177 Chinese companies and 2,551 fishing trawlers are currently authorized to fish on the high seas across the Pacific, Indian and Atlantic oceans, the waters near the Antarctic and the waters administered by China's partners, and their annual output is roughly 2.3 million metric tons, the white paper said.

The report said that six Chinese companies have been permanently disqualified from fishing offshore since 2016, while operations of another 22 have been temporarily suspended due to minor offenses over the same period. Some of the offenders were reported by foreign governments and international organizations.

"China strictly policed its footprint in deep-sea fishing and maintained zero tolerance toward misconduct through legislation and administrative law enforcement measures," it said, adding that China had adopted a digital logging system to prevent overfishing of tuna, squid and saury, among others.

The white paper highlighted China's support for multilateral crackdown on illegal fishing. Such endeavors include deploying law enforcement vessels regularly in the North Pacific Ocean, starting in 2020, and barring sanctioned fishing boats from refueling and replenishing supplies at Chinese ports under a regional pact since 2018.

As a front-runner in harvesting deep-sea catch known for their health benefits, China's presence in offshore fishing grounds can be traced back to more than 4,000 years ago.

Modern deep-sea fishing picked up in China in 1985, as it launched bilateral cooperation with over 40 countries spread across Asia, Africa, South America and Oceania.

China also participated in multilateral fishery management under the framework of the United Nations and in the spirit of international laws, and supported research aimed at protecting sea mammals and other endangered species, the report said.

Since embracing the concept of ecological civilization in 2012, the country has been working to limit fishing intensity and combat illegal practices to ensure responsible and sustainable use of ocean resources, it said.

As part of the efforts, China implemented in 2020 a self-imposed, three-month trial moratorium on fishing in international waters in Southwest Atlantic and East Pacific. The fishing ban became a formal policy the next year.

The country's 14th Five-Year Plan (2021-25) capped the number of deep-sea fishing boats at 3,000 and limited their total catch to below 2.3 million tons a year.

China exported 3.74 million tons of aquatic products in 2020 to the United States, Europe, Southeast Asia and Japan, among others, which made up 12 percent of the world's total exports of aquatic products that year, according to the General Administration of Customs.