Figure legends
Figure 1: Map of study area, including the location of sampling sites. Photos showing the Spremberg Reservoir with inflow of brown, iron-rich water (upper photo), and the dam with outflow of clear water (lower photo). Red arrow depicts flow direction. Photos were taken in 2020 and 2021 and kindly supplied by the Lausitzer und Mitteldeutsche Bergbauverwaltungsgesellschaft mbH, Senftenberg/Germany.
Figure 2: Abundance of benthic macroinvertebrates (individuals m-2) collected at the three locations upstream (i.e., high iron concentrations) and the three locations downstream (i.e., low iron concentrations) of the dam. See Appendix 1 for a list of invertebrate taxa found at each site.
Figure 3: a) Abundance (represented as catch per unit effort, CPUE, individuals 1000 m-1) and b) biomass of fish species (represented as biomass per unit effort, BPUE, g 1000 m-1) collected at the three locations upstream (i.e., high iron concentrations) and the three locations downstream (i.e., low iron concentrations) of the dam. See Appendix 2 for a list of species abundances at each site.
Figure 4 : Contribution of aquatic and terrestrial resources to the diet of the three dominant fish species (roach, perch, and bleak), as depicted by the terrestrial index of fishes. A higher index indicates higher contribution of terrestrial resources to the diet. Boxplots indicate medians, with whiskers expanding to the 25th and 75th percentile. Dots depict outliers and asterixes level of significance (***:P ≤ 0.001; **: P ≤ 0.01).