NANJING/GUANGZHOU/SHANGHAI, March 1 (Xinhua) -- The annual fishing ban on China's rivers from March 1 to June 30 began Thursday.

The ban covers the main streams, tributaries and lakes along the Yangtze, Huaihe, Minjiang and Pearl rivers.

Nearly 10,000 people and 1,000 vessels from 21 provincial regions will work to prevent illegal fishing and related activities during the moratorium.

Local governments will provide allowances to fishermen affected by the ban.

The fishing restriction aims to protect aquatic resources and biodiversity as overfishing threatens resources, authorities said.

"The ban period covers the spawning season for most aquatic life in the rivers, which will boost aquatic resources and help maintain the ecological balance," said Chen Shi, an official in Jiangsu Province.

The annual fishing ban was initiated in 2002 on the Yangtze River, the country's longest, and on the Pearl River in 2011.

The ban was extended from three months to four in the Yangtze River in 2016 and in the Pearl River in 2017, in a bid to better protect fish resources.

The fishing ban has, to some degree, contained the deterioration of fishery resources along Chinese rivers, said Cheng Jianxin, a marine surveillance official.

In February, China announced it would initiate an annual fishing ban on the Yellow River, the second longest in the country, between April 1 and June 30 starting 2018.

Fishing for scientific studies, taming and breeding purposes during the ban period should be approved by authorities of provincial level or higher.