CHANGCHUN, May 14 (Xinhua) -- Chinese fishery authorities have released 400,000 salmon fry into Tumen River, which forms the border between China, the Democratic People's Republic of Korea (DPRK) and Russia, to conserve the region's natural ecology.

It was the second such move since 2008 when 100,000 salmon fry were released into the Tumen River in northeast China.

"Our goal is mainly to help enrich the aquatic life and preserve the ecological environment in the river, and also, to help increase fishermen's income," said Wang Zhaojun, director of the Jilin Provincial Fishery Bureau.

"Meanwhile, we hope to, through the move, enhance the public's environmental awareness and promote harmonious development between man and nature," he said.

The salmon fry released were about six months old and each five centimeters long. They would stay in the Tumen River's estuary for about three months and then swim into the Sea of Japan, Wang said.

"They are expected to return to the Tumen River to lay their eggs in four to five years," he said.