Macquarie Marshes: Murray-Darling River Basin (Australia)

Abstract

The Macquarie Marshes are a large Australian floodplain wetland within the semi-arid region of the Murray-Darling River Basin, a Ramsar listed wetland of international importance recognised globally for their high biodiversity and conservation values. Unique flooding regimes from variable river flows of the Macquarie River are vital for a flourishing mosaic of diverse wetland habitats: open water lagoons and vast common reed-beds to lush water couch meadows to extensive stands of river red gum forests and woodlands. They are renowned for high waterbird abundance and diversity, especially colonial nesting waterbirds which can breed in amazingly large numbers, up to hundreds of thousands at a time. Fish, frogs, turtles and a diversity of other fauna species rely on the Marshes. The Macquarie Marshes also support a rich Aboriginal and European cultural heritage. But river regulation by large dams and river flow extraction have altered river flows changing flooding regimes. A concomitant decline in waterbird abundance and breeding events, fish populations, and the health of river red gum trees occurred. Recent concerns about degradation in the Murray-Darling River Basin initiated an Australian governments’ recovery program, significantly increasing the water allocated to the Macquarie River for environmental purposes. Evaluation of environmental water use under the Basin Plan is vital for effective adaptive management, but will be contingent on a commitment to long-term ecological research and monitoring.