HARBIN, June 11 (Xinhua) -- China on Monday imposed a 35-day fishing ban on the mainstream of the Heilongjiang River on the border with Russia.

The annual fishing moratorium, scheduled to end on July 15, aims to protect fish spawning and increase fish stocks to make the development of local fishery industry more sustainable.

Authorities in the northeastern province of Heilongjiang also impose annual fishing bans on other natural bodies of water. The ban on the China-Russia border lake, Xingkai Lake, started on June 6 and will end on July 20.

During these periods, all fishing boats and equipment should be removed from the water. Sellers of aquatic products should have permits from local fisheries authorities.

The Heilongjiang River is one of the major salmon spawning areas in China.

In early May, fisheries authorities in Heilongjiang released 2 million salmon fry into the Heilongjiang River in a bid to boost stocks of the species.