7-epi-cylindrospermopsin and microcystin producers among diverse Anabaena/Dolichospermum/Aphanizomenon CyanoHABs in Oregon, USA

•Microcystins MC-LR and [Dha7]MC-HtyR and 7-epi-cylindrospermopsin were shown to be produced by Dolichospermum strains in Oregon, USA•Congener identity was linked to mcy and cyr cyanotoxin genes•Dolichospermum sp. DET69 (cyr+) and Dolichospermum sp. DET73 (mcy+) are the toxin producers in Detroit Reservoir, a major source of drinking water•MC-LR is produced by two distinct Dolichospermum strains in three other Oregon lakesDiverse HAB-forming members of the Nostocales ADA clade (Dolichospermum and Aphanizomenon flos-aquae) in the US Pacific Northwest include producers of microcystin, cylindrospermopsin and anatoxin-a, as well as strains lacking cyanotoxin genes.