The data include the abundance and community compositions characterized using qPCR and metagenomic sequences. This dataset is associated with the following publication: Jeon, Y., I. Struewing, K. Clauson, N. Reetz, N. Fairchild, L. Goeres-Priest, T. Dreher, R. Labiosa, K. Carpenter, B. Rosen, E. Villegas, and J. Lu. Dominant Dolichospermum and microcystin production in Detroit Lake (Oregon, USA). Harmful Algae. Elsevier B.V., Amsterdam, NETHERLANDS, 142: 102802, (2025).