Officials of the Hwanghae Iron and Steel Complex have installed mobile cage-nets in the Taedong River and introduced a vertical fish breeding method based on the ecological habits of fishes.
In general, fishes live in different sections of water according to species, and their feed organisms vary from each other.
Accordingly, they breed silver carps in the upper section of the cage-nets, Aristichythys nobilis and grass carps in the middle, carps and Ryongjong fish in the lower section and Cristaria plicata at the bottom.
They also make effective use of natural feed by moving the cage-nets into the water area abundant in feed organisms.
They say they can produce over 10 tons of fish this year.