Farming salmon in sea pens devastates salmon populations and migratory trout populations closest to sea pen farming areas. In Iceland, salmon farming is particularly harmful because the salmon used in the open net pens is Norwegian. Farmed salmons regularly escape from sea pens and swim into Icelandic rivers to spawn, with associated genetic mixing and destruction of Icelandic salmon stocks. Diseases and parasites accompanying farmed salmon also reduce the life expectancy of wild Icelandic salmon. The same applies to sea trout and sea char near sea pens.