Invertebrate communities in freshwater streams form the basis of many environmental biomonitoring protocols. However, because of several practical limitations, these studies often rely on coarse taxonomic resolution. It is possible that this will group together species with different environmental preferences, thus masking the relationship between taxonomic composition and environmental variables. My thesis looks at the relationship between taxonomic resolution and our ability to characterise aquatic invertebrate communities using metacommunity theory. I found that for most orders, as taxonomic resolution increased the proportion of community composition variability explained by the environment decreased. These results suggest the ecological interchangeability of closely related species in this system, given the environmental variables I measured. My thesis illustrates the importance of using a metacommunity context in environmental monitoring and the need to establish the most efficient taxonomic resolution for routine monitoring.