Spatio-temporal variability of native flow-cued pawning fish larvae in association to environmental water in the lower River Murray

JUAN P. LIVORE; QIFENG YE

Darwin

Congreso; Joint Congress of the Australian Society for Fish Biology and the Australian Society for Limnology 2014; 2014

Australian Society for Fish Biology y Australian Society for Limnology

Waterhas become a precious resource in many parts of the world and its informedmanagement is essential to a successful balance between human and environmentalneeds. As part of achieving this balance environmental flows have received muchattention, but little rigorous biological evaluation. However reliably investigatingbiological responses to find causal links to E-flows has proven to be achallenge. The monitoring of larval fish abundance over eight years in the lowerRiver Murray under a broad range of flow scenarios, including the Millenniumdrought, natural flood and within channel flows with delivery of E-flows,provides reliable information that associate E-flows to the presence of larvae offlow-cued spawning native fish. Our results show that the delivery of a flowpulse of appropriate magnitude and timing can prolong the period of time over whichlarvae of flow-cued spawning species are found in the lower River Murray. The temporal extension ofearly life history stages in the water column increases total abundance oflarvae and potentially recruitment success. The results also highlight greaterabundances of larvae in the gorge than floodplain geomorphic region of the lowerRiver Murray, indicating the need for large spatial scales in the monitoring ofE-flows. Identifying causal links of the observed patterns and relating them toecological processes and function is essential for E-flow management in thelower River Murray and merits future research.