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General Category => Fish Information - Trivia - Reference material => Topic started by: Editor on June 05, 2012, 09:14:52 AM

Title: What drives blackwater events?
Post by: Editor on June 05, 2012, 09:14:52 AM
What drives blackwater events?

Blackwater events were seen across the Murray‐Darling Basin after the widespread flooding of 2010‐2011, with over 2000km of river channels affected. This situation provided researchers with an unusual opportunity to study what was driving the formation of blackwater in the Murray‐Darling. Blackwater occurs when the breakdown of high levels of dissolved organic carbon (from floodplain vegetation, leaf litter and soil) in the water column depletes the oxygen available for fish and other aquatic organisms. This can cause fish kills. The researchers found that there were multiple factors contributing to both the development and the persistence of this blackwater event. After the decade‐long drought the prolonged inundation of both forested and agricultural floodplains meant large amounts of carbon were dissolved into the floodwaters. In addition, altered flow patterns, due to a combination of climatic effects and river regulation also contributed to the high levels of dissolved carbon. Read more about this research by Whitworth and others in the Journal of Hydrology: http://dx.doi.org/10.1016/j.jhydrol.2012.04.057 (http://dx.doi.org/10.1016/j.jhydrol.2012.04.057)


A summary of the blackwater event in the Murray, Murrumbidgee and Lower Darling River catchments in March 2012 is available from:
www.dpi.nsw.gov.au/fisheries/habitat/threats/fish-kills/black-water-events-causing-fish-kills-in-the-murray,-murrumbidgee-and-lowerdarling-river-catchments-march-2012 (http://www.dpi.nsw.gov.au/fisheries/habitat/threats/fish-kills/black-water-events-causing-fish-kills-in-the-murray,-murrumbidgee-and-lowerdarling-river-catchments-march-2012)