The Youth Tudan and Samsok breed-fish farms secured high-yielding adult fishes and raised the survival and growth rates by breeding them in a scientific and technological way.

The Ryongsong and Sunan breed-fish farms have conducted artificial insemination in a scientific way according to the biological characteristics of each species and increased the hatchability by ensuring the water quality and temperature of hatchery ponds, thus boosting the fry production per unit area.

Meanwhile, breed-fish farms in South Phyongan Province released millions of fry into rivers and lakes.