Millions of amur ides are migrating upstream to reach Dali Lake for spawning.
Dali Lake or Dalinur Lake is the second largest lake in north China’s Inner Mongolia Autonomous Region. Every year, amur ides swim to warm freshwater rivers from Dali Lake to reproduce.
Because the water salinity is five percent, amur ide and crucian carp are the only species of fish that inhabit the lake. They are the main food source for birds including fish gulls, herons, and cormorants.
The fish migration is slightly late this year. “Since their migration period is relatively short, the number of fish in the river this year is more than in previous years,” said Sun Lixiao, deputy chief of the production technology section of a local fishery.
The birds eat about 1,500 tons of amur ide every year. In the migration period, the birds can get the fish with no effort.
However, rising salinity of the lake, bird predation, overfishing, and climate change all pose a threat to the fish population. In order to maintain the balance of the biological chain, local fisheries have carried out propagation.