The Biota of Intermittent Rivers and Ephemeral Streams: Aquatic Invertebrates

Intermittent rivers and ephemeral streams (IRES) support diverse and sometimes distinctive aquatic invertebrate communities. Although flow intermittence has been linked to reduced taxa richness, the highly variable environmental conditions that characterize IRES can enhance both taxonomic and functional diversity, with different invertebrates characterizing flowing, pool, dry, and flow-resumption phases. Aquatic invertebrate communities, which include specialist taxa, have a diverse range of adaptations to promote their survival in the pools and dry bed sediments that characterize IRES channels during nonflowing phases. These tolerant organisms and recolonists from outside of IRES channels allow communities to recover once flow resumes. IRES invertebrate communities have been affected by human activity, especially where flow regimes have been altered by climate change, water resource pressures, and changing land use. Restoration initiatives, from riparian revegetation projects to conservation strategies that protect individual species, are therefore needed to safeguard aquatic invertebrate community diversity in IRES.