([P.O. Nordberg, unpublished data],[Christensen 2009], [Runnström 1940] and [Ros 1981]). Therefore, the salmon & trout populations in the lake today heavily rely upon fish farming of smolts - which are also released into the lake and some of its tributaries every year ([Swedish Board of Fisheries (Fiskeriverket)], [Fortum (the hydroelectric operating firm)], [the Värmland County Administrative Board (Länsstyrelssen I Värmland)] and [Statistics Sweden (SCB, http://www.scb.se)]). But this procedure has by no means proven to be adequate in replacing the previous natural production capacity held in these waters, leading to a demise in both volumes and the overall quality of the remaining wild strains. The proportion of wild salmon and trout combined in the commercial catch in Vänern has increased from a maximum of 5% in 1997 (Fiskeriverket and Länsstyrelsen i Värmlands län, 1998) to up to 30–50% by 2008 (Degerman, 2008; Hållén, 2008; Johansson et al., 2009). The increasing proportion of wild fish in the lake could be a result of (1) increased natural production and/or protection of wild fish, and (2) declining numbers and/or decreased survival of hatchery smolt (Eriksson et al., 2008). Because the current fisheries in Lake Vänern are completely reliant on hatchery production, improving the survival rates of hatchery smolts could increase catch rates. Recently, however, declines in catch rates of hatchery-reared salmon and trout in Sweden nationwide have raised concerns about the condition, or ‘quality’, of the smolts being released (Eriksson et al. 2008; Swedish Board of Fisheries 2008). The power companies, bound by compensational duties due to verdicts in given licenses, have also been striving to release a higher percentage of 1 year old fish, as opposed to the more natural 2-year cycle. This entire prevailing situation has also led to a negative impact on both of the remaining populations genetic diversity (Ros, 1981) and their unique yet poorly preserved traits, leading to their present endangered status. Other fish The most important large fish in the lake are brown trout (Salmo trutta) and zander (Sander lucioperca). The most important small fish is the stickleback. Vänern has five distinguished species of whitefish: Coregonus pallasii (also common in Neva, Gulf of Finland, Baltic Sea) Lacustrine fluvial whitefish (Coregonus megalops) Coregonus maxillaris (population mainly known around Sweden) Coregonus nilssoni Valaam whitefish (Coregonus widegreni) Coregonus maxillaris Birds The most common birds near Vänern are terns and gulls. Great cormorants have returned and are flourishing. This has contributed to