ØKOSTOR 2021: Basisovervåking av store innsjøer. Utprøving av metodikk for overvåking og klassifisering av økologisk tilstand i henhold til vannforskriften : surveillance monitoring of large norwegian lakes 2020. Testing of methodology for monitoring and classification of ecological status according to the Water Framework Directive surveillance monitoring of large norwegian lakes 2020. Testing of methodology for monitoring and classification of ecological status according to the Water Framework Directive