Channels and oxbows came into being by shifting of the mainstream of the Sava River in the course of time and that is the reason why they were cut off form the main river. They are situated near the mainstream and most of them are not directly connected to the Sava River. There are 22 channels and oxbows in the area of the Nature Park. Although they are not affected by floods, they are under the influence of rainfall as well as ground water and they are the source of rich flora and fauna. Lonjsko Polje is teeming with different fish species. For this reason traditional fishing with traditional fishing tools was widespread in the past. In this alluvial region where high waters sometimes stay as long as six months, there is one of the greatest hatching grounds of carp in the whole of Europe. The Sava River with its confluents the Lonja, Strug, Pakra, Ilova and Trebež is a genuine anglers’ paradise, offering both beautiful countryside and fishing grounds as well as numerous fish species (catfish, pike, perch, carp, etc.).