Drivers of macroinvertebrate assemblages in littoral and pelagic habitats of a large shallow lake: implications for bioassessment

Different measures of macroinvertebrate diversity (species diversity, functional diversity, phylogenetic diversity) and functional feeding groups (FFGs) are commonly used to assess the ecological status of large shallow lakes. In this study, biodiversity and FFGs in a large shallow lake, Lake Hongze, differed between littoral and pelagic habitats, with the spatial variability of littoral assemblages more correlated with nutrient concentrations, whilst pelagic assemblages were more associated with wave-induced disturbance (e.g., mean effective fetch). Species diversity was poorly correlated with measures of nutrient concentrations, whereas functional diversity, phylogenetic diversity, and functional feeding groups are promising indicators of nutrient concentrations. Lastly, our findings support the use of biodiversity and FFGs to disentangle the effects of nutrients and wave-induced disturbance on macroinvertebrate assemblages. Furthermore, monitoring both littoral and pelagic habitats in large shallow lakes is recommended to better understand and quantify ecosystem changes.