Beijing, Aug 16 (IANS): Excessive fishing is becoming a threat to the marine ecosystem of China -- and the authorities are mulling a 10-year ban on fishing in the country's longest river Yangtze.

According to China's Ministry of Agriculture, fishery resources are severely depleted and there are "no fish" in some areas such as the East China Sea.

"The situation in the Yellow Sea and the Bohai Sea is no better than the East China Sea, while the situation in the South China Sea is better," Wang Yamin, a professor with the School of Oceanography at Shandong University was quoted by state media on Tuesday as saying.

Despite a moratorium being in place during designated months, over-fishing continues in the country. Fishing is a source of livelihood for many in China and illegal trade adds to the pressure.

Academicians at the Chinese Academy of Sciences have called for a 10-year ban on fishing in the Yangtze instead of a temporary moratorium.

The country's annual catch in the seas hit 13 million tonnes in recent years, although the allowed volume is set between 8 million to 9 million tonnes, according to the ministry.

The ministry added that currently the annual freshwater catch in the Yangtze River, which accounts for 60 per cent of the country's total freshwater fish output, was about 100,000 tonnes per year, less than a quarter of what Yangtze fishermen routinely caught in 1954.

The Yangtze is regarded as a cradle of China's freshwater fisheries and a valuable reserve of aquatic biodiversity.

The Yangtze fishing moratorium started in 2003, covering 10 provinces and municipalities. The ban originally took effect from February to April in the upper reaches, and from April to June in the lower reaches. In 2016, the ministry extended the area and the time to four months.

China has also imposed an annual summer fishing ban in the Yellow Sea and East China Sea since 1995, and later in the South China Sea.