National Environmental Monitoring in Sweden. Monitoring of heavy metals in fish is performed in 110 trend lakes in Sweden. Annual sampling is carried out in 32 lakes, of which seven are in AMAP area. Three fish species have been selected: Arctic char (Salvelinus alpinus), Northern pike (Esox lucius), and Perch (Perca fluviatilis). A selection of metals is analysed in prepared samples of muscle and liver tissue. Analysed metals in liver are : Al, Ag, As, Bi, Cd, Cr, Cu, Ni, Pb, Sn and Zn. In muscle samples Hg and stabile isotopes δ 15N, δ 13C are analysed.