Fit for Purpose—Analyses of Macroinvertebrate Communities for Environmental Flow Assessment

Environmental flow assessment is crucial for sustainable water management. In assessing environmental flows using the most common methods, for example, habitat suitability modelling (HSM), it is assumed that the distribution of aquatic organisms is driven by hydraulic features and substrate type of the habitats. However, most of the existing research does not consider analyses of organisms' ecological traits and their community structure. To bridge this gap, we present the results of analyses of macroinvertebrate communities carried out for environmental flow purposes. The study was performed at two reaches of the Flinta River, a European, lowland, temperate and perennial river, with different degrees of hydromorphological alterations. We state that more detailed analyses of organisms' community in environmental flow assessment are needed. Thus, we assess the dissimilarity of the organism community structure sampled during field campaigns by means of statistical tests, and we analyse macroinvertebrate ecological traits and indicators commonly used to evaluate river status. Afterwards, we discuss the applicability of the analyses and provide recommendations for the future environmental flow assessments.