Introduced European minnow Phoxinus phoxinus in alpine lakes may increase total mercury concentration in brown trout Salmo trutta

In Norway, the cyprinid European minnow Phoxinus phoxinus has been spread far outside its previous natural distribution area, with lots of establishments in mountain lakes where brown trout Salmo trutta originally was only fish species. We have analysed δ15N and total mercury (THg) concentration from eight lakes, situated between 1031 1244 m a.s.l. on Hardangervidda plateau, southern Norway. One is inhabited by minnow, while other seven were significantly higher population co-existing indicating a trophic position this than allopatric populations, probably caused piscivory, as indicated frequent occurrence diet. The concentrations lake had values up to around 0.4 mg THg per kg wet weight. without together values, that translocation establishment may increase previously thereby also level.