Fish abundance data (fish per m) collected during the MACRO project in Mongolia. We collected fish assemblages in river networks of two different ecoregions, the Forest Steppe (FS) and Grassland (G), in 2017 and 2019.

We established reaches for fish collections measuring at least 20 times the mean wetted width of the river at the sampling area. We collected fishes by single-pass backpack electrofishing supplemented with angling (Ball State University IACUC #126193) following the American Fisheries Society standard collection protocols (Bonar, Hubert, & Willis, 2009), and reported fish abundance as fish-per-meter sampled.

We sampled fishes during one month expeditions in each of the river networks during the month of August in 2017 for the FS and 2019 for the G.