Dedication to River Murray ecologist Keith Walker

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A special issue of research articles dedicated to A/Prof Keith Walker (1946 – 2016)  has just been published in the Transactions of the Royal Society of South Australia. The rivers of the Murray-Darling Basin are central to the lives of many in south-eastern Australia, through provision of water for human consumption and agriculture, through ecosystem services and by providing enormous recreational and cultural capital. The development of the River Murray as a water resource has fundamentally altered the integrity of the river’s aquatic and floodplain ecosystems. Many researchers, conservationists, managers, and policymakers have devoted their careers to a better understanding of the ecology of this river system, with the ultimate aim of rehabilitating it. A central character in River Murray ecological research was Keith Forbes Walker. This special issue presents a number of new articles concerning the ecology and geomorphology of the River Murray. These have been authored by Keith’s former students and colleagues, providing exemplars of his intellectual legacy. The articles cover a breadth of Keith’s research interests, including the hydrology and hydraulics of the River Murray, geomorphology, aquatic and terrestrial vegetation, fish communities and ecology. It is hoped that this compilation is useful for those with an interest in the River Murray and forms a fitting tribute to the legacy of Keith Forbes Walker. Of particular note, is a paper by SARDI and University of Adelaide staff that discusses the contribution Keith made to the botanical, ecological and hydrological understanding the Lower River Murray and beyond. The paper states that a major legacy of Keith Walker is the realisation by water managers that the positive ecological outcomes of increased water-level variability in the lower River Murray outweigh the (perceived) negative impacts to consumptive users. However, the effect of the different components of the water regime (e.g. timing, magnitude, seasonality, duration, rate of inundation and draw down) are currently not well understood. Furthermore, the impact of lateral and longitudinal connectivity and flow on vegetation dynamics (particularly in regards to propagule transport) have received less attention from researchers and managers in comparison to the effects of changes to water levels. These are important considerations moving forward in management of the lower River Murray with regards to the provision of environmental flows and the use of engineering solutions (existing and proposed infrastructure) for environmental outcomes The special issue editorial can be accessed here  (and you can email jennie.fluin@sa.gov.au for copies of any of the other papers).