Salmonids are important in icelandic freshwater ecosystems, and have been studied extensively for decades. Particular focus has been on diversity in Arctic charr (Salvelinus alpinus) and Brown trout (Salmo trutta), with emphasis on ecological and evolutionary questions. Researchers at the University of Iceland, initially led by Sigurdur S. Snorrason have focused on questions about ecological diversity in this species, also using it to study morphological and genetic evolution. This has focused a lot on the Arctic charr in Lake Thingvallavatn, but other systems like dwarf charr in springs, sympatric lake charr and anadromous populations have also been explored. This has involved collaborations with colleagues at Holar University, the Marine and Freshwater Institute and other international and national institutions. This group has also explored similar questions in populations of brown trout and other salmonids.

Pictured are large benthic charr in Ólafsdráttur. They gather in the shallows, where the cold water from underground streams generates ideal conditions for spawning (see study on spawning sites).