In this area it was extremely difficult to build a permanent road, since the bridges and parts of the roads were constantly being washed away when the glacial rivers reached their maximum discharge, usually in July and August. Clear-water rivers are of two kinds. One drains the old basalt areas and has a variable discharge with maximum flow in late spring. Lakes in Iceland are abundant, but most of them are rather small. Lake M vatn is world renowned for its fascinating scenery and incredibly rich bird life.
Icelandic rivers abound with salmon, while trout and char are plentiful in lakes and streams.
Two other species of freshwater fish are also to be found, the eel and the three-spined stickleback. None of these five species are really freshwater fish, but represent marine species that are establishing themselves in fresh water. Hv t in Borgarfj r ur, in West Iceland.