Volunteers fill a pool with Chinese sturgeons before releasing them into the Yangtze River in Yichang, Hubei province, on Friday. A total of 1,600 Chinese sturgeons, 20,000 Chinese longsnout catfish and 20,000 Chinese high-fin banded sharks were released into the Yangtze to enhance its fish population and improve the aquatic environment. The Chinese sturgeon and the Chinese high-fin banded shark are rare fish species unique to the Yangtze River basin.