Short-term effects of a prolonged blackwater event on aquatic fauna in the Murray River, Australia: considerations for future events
Short-term effects of a prolonged blackwater event on aquatic fauna in the Murray River, Australia: considerations for future events
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DOI：
10.1071/mf11275
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发表时间：
2012-01-01
影响因子：
1.8
通讯作者：
Lieshcke, J.
中科院分区：
文献类型：
--
作者：
King, A. J.;Tonkin, Z.;Lieshcke, J.
黑水含有大量的溶解有机碳，可以被微生物迅速消耗，有时导致极低水平的溶解氧（缺氧），对水生生物造成严重后果，包括鱼类死亡。2010年末的干旱降雨淹没了澳大利亚墨累-达令盆地南部barma - millewa森林的大片地区，导致森林和墨累河下游出现了长时间的缺氧黑水事件。本研究调查了黑水事件对鱼类和小龙虾的短期影响。与未受影响的样地相比，受黑水影响的样地出现的墨利小龙虾（Euastacus armatus）的丰度显著高于未受影响的样地，这些样地易受干燥、捕食和开发；大量死亡或濒临死亡的虾和幼虾；本地鱼类的丰度显著降低；但也含有相似丰度的外来鱼类（尤其是普通鲤鱼）。引起这些变化的机制的性质以及该事件对河流系统的长期意义仍然是未来研究的重要领域。我们还提出了一系列减少黑水影响的管理考虑因素，例如长期干旱后环境供水的时机以及在洪水期间保持河流与洪泛区连通性的重要性。
Blackwater contains high levels of dissolved organic carbon that can be rapidly consumed by microbes, sometimes leading to extremely low levels of dissolved oxygen (hypoxia) and drastic consequences for aquatic life, including fish kills. Drought-breaking rains in late 2010 inundated large areas of the Barmah-Millewa Forest, southern Murray-Darling Basin, Australia, and resulted in a prolonged hypoxic blackwater event within the forest and the Murray River downstream. This study investigated the short-term effects of the blackwater event on fish and crayfish. Compared with non-affected sites, blackwater affected sites had: significantly higher abundances of emerged Murray crayfish (Euastacus armatus) that were vulnerable to desiccation, predation and exploitation; large numbers of dead or dying shrimp and yabbies; significantly reduced abundances of native fish; but contained similar abundances of alien fish species (particularly common carp, Cyprinus carpio). The nature of the mechanisms that caused these changes and the longer term significance of the event on the river system remains an important area for future research. We also propose a range of management considerations for reducing the blackwater impacts, such as the timing of environmental water delivery after prolonged drought and the importance of maintaining river-floodplain connectivity during flood periods.