Freshwater is a limited resource, and freshwater is normally THE limiting factor for terrestrial primary-production.
Norway has luckily an abundance of freshwater resources, but freshwater is easily affected by human activities like hydropower production and introduced species. Freshwater ecology is a specific subject taught at NTNU (BI 3037 Freshwater ecology).
Ecology of salmonid fishes like brown trout, Atlantic salmon and Arctic char is an important research topic in freshwater ecology. Salmonid fishers are mainly distributed in northerly temperate and Polar regions, in both Europe and North-America, and these fishes show a wide range of life-histories. Salmonid fishes use the limited food energy into different body parts during different life stages and seasons. This reveals life-history differences, used to understand effects of manipulation of nature in e.g. hydropower production or changing climate. The effects of rapid hydropower regulation, hydropeaking, are investigated together with collaborators at the FME-research centre: Centre of Environmental Design of Renewable energy (CEDREN). Energetic changes can be used to investigate the effects of human interaction with nature, like effects of hydropower regulation or aquaculture.
Aquaculture industry induces changes on wild Atlantic salmon through the effects of e.g. escapes or parasites (salmon lice). Hybridization between farmed and wild or between anadromous and landlocked Atlantic salmon are examples of research showing the effects of hybridization and thus erosion of the natural occurring genetic resources of a species or subspecies. Norway has a responsibility to manage the salmonid fishes so they are preserved for future generations. Atlantic salmon is today heavily affected by changes induced by industry activity and conservation of salmonid species in general is a major task for future management of these species.