The Yangtze River's ecological environment is getting better — and to prove it 12 fish species have reappeared in the river's mouth.
They include the spotted maigre and the Chinese long-snout catfish.
From 2012, more than 30 monitoring spots were set up in the Chinese Sturgeon Nature Conservation Area at Chongming Island near the estuary of Yangtze River, but the 12 species were not observed until the past year.
Six species such as the spotted maigre have been frequently found in the conservation area in the past year, and the other six species, such as the long-snout catfish are also seen in the area, though not as frequently.
Yangtze River's estuary, the passage for fish to travel between the river water and East China Sea, plays a key role in the fishery development along the huge river.
This is why the conservation area was set up at Chongming Island.
In 2012, the conservation area's management office set up an artificial fish shelter in the reservation area. The shelter comprises 2.5-meter-long bamboo poles with holes. The bamboos are set in the riverbed and the holes allow sand to flow in to stabilize the bamboos in the water.
Moss grows on the poles, providing a source of food of fish, and loose sand at the bottom can attract creatures that enjoy swimming in sand. The poles also serve as a shelter for young fish and shrimps when under attack from aggressive fish.
Over the past five years, more than 330,000 bamboo poles have been set up in the river, and the shelter now covers an area of 13,000 square kilometers.
Officials said the shelter has made a significant contribution to improve the eco-diversity of the Yangtze River.