Responses of fish assemblages to flooding of the Narran Lakes ecosystem, May 2008: Final Report to the New South Wales Department of Environment and Climate Change

Abstract

This report details the spatial and short-term temporal responses of fish assemblages and recruitment to prolonged flooding in the Narran Lakes system, north-western NSW, that occurred between December 2007 and May 2008. A range of native and alien fish species are known to occur in this catchment (McDowall 1996; Lintermans 2007), and a number of weir structures exist within downstream reaches of the Narran River. Water is regularly extracted from the Narran River upstream of the terminal wetlands for irrigated cropping and stock and domestic needs. During summer-autumn 2008, the Narran Lakes system experienced large-scale flooding and floodplain inundation. To prolong this inundation, the Murray-Darling Basin Commission purchased a quantity of water from the upstream Queensland irrigation district to maximise the outcomes of colonial waterbird breeding that occurred within the Narran lakes Nature Reserve (MDBC 2008; Peter Terrill personal communication). Due to the considerable amount of money spent purchasing this water, the NSW Department of Environment and Climate Change, the Murray-Darling Basin Commission and the Australian Department of Environment, Water, Heritage and the Arts were interested in responses of fish assemblages and recruitment to this prolonged flooding to gain information for the improvement of future water delivery for conservation purposes in the region.