Journal Article

Water Regimes and Macroinvertebrate Assemblages in Floodplain Wetlands of the Murrumbidgee River, Australia

Chessman, Bruce C, Hardwick, Lorraine

2014

Overview

Geomorphic change, water resources development and climate change can alter the timing, frequency, magnitude and duration of replenishment of floodplain wetlands via overbank flows. If we understand the ecological consequences of these hydrological changes, environmental water allocations can be used more effectively to sustain wetland biodiversity and associated ecosystem processes. We analysed longterm monitoring data for 13 wetlands on the floodplain of the Murrumbidgee River in south-eastern Australia to determine how aquatic macroinvertebrate assemblages related to the proportion of time during which a wetland contained water. The more temporary wetlands had significantly different and poorer assemblages than the more permanent ones, with frequency of occurrence significantly negatively related to permanence for eight invertebrate genera and positively related for 17. The invertebrates most strongly associated with more temporary wetlands were mainly crustaceans whose resting stages withstand drying, together with highly mobile insects. Those associated with more permanent wetlands included a prawn, molluscs and less mobile insects. These findings suggest that maintaining a broad spectrum of hydrological regimes at the local scale is necessary if macroinvertebrate diversity on the Murrumbidgee River floodplain is to be sustained.

• Subject: Mollusca