Abstract The use of freshwater for human consumption and agriculture has resulted in many wetland ecosystems being some of the most seriously impacted ecosystems in the world. In attempts to rehabilitate wetland ecosystems environmental flows are used to restore parts of the hydrological regime altered by human water use. The use of environmental water intends to improve ecosystem health, but frequently aims to have specific outcomes for populations of higher-order consumers such as iconic fish and bird species. To date, research and monitoring has mainly focused on understanding ‘flow-ecology’ relationships, without investigating the mechanisms underlying them. We sought to understand the importance of different basal food sources to the growth of the endangered Murray cod in temporary wetland systems using fatty acid biomarkers. We flooded replicate mesocosms with two different wetland soils to produce sufficient zooplankton prey to sustain and grow Murray cod larvae for approximately 2 weeks. The fatty acid profiles of Murray cod and percentages of different biomarkers were compared at the start and finish of the experiment and our results suggest that the most important basal food source is green algae. However, the biomarkers of diatoms, cyanobacteria and bacteria also increased and differed between wetlands with different hydrological regimes. It is unclear if our results can be extended to other wetland systems and we encourage further research both into the relationship between length of wetland flooding and invertebrate densities in other systems. We also encourage research into the mechanistic pathways in which green algae carbon is transferred through food webs to higher order consumers in wetland systems to help generalise our results to other wetlands and support the management of wetlands through the timing and duration of flooding from environmental water.

中文翻译：

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湿地中层世界墨累鳕（Maccullochella Peelii）的基础食物来源

摘要 淡水用于人类消费和农业导致许多湿地生态系统成为世界上受影响最严重的生态系统之一。在恢复湿地生态系统的尝试中，环境流量被用来恢复因人类用水而改变的部分水文状况。环境水的使用旨在改善生态系统健康，但通常旨在为诸如标志性鱼类和鸟类等高级消费者群体带来特定结果。迄今为止，研究和监测主要集中在理解“流动-生态”关系上，而没有研究它们背后的机制。我们试图使用脂肪酸生物标志物了解不同基础食物来源对临时湿地系统中濒临灭绝的墨累鳕鱼生长的重要性。我们用两种不同的湿地土壤淹没了复制的中宇宙，以产生足够的浮游动物猎物来维持和生长墨累鳕鱼幼虫大约 2 周。在实验开始和结束时比较了墨累鳕鱼的脂肪酸谱和不同生物标志物的百分比，我们的结果表明，最重要的基础食物来源是绿藻。然而，硅藻、蓝藻和细菌的生物标志物也有所增加，并且在不同水文状况的湿地之间存在差异。目前尚不清楚我们的结果是否可以扩展到其他湿地系统，我们鼓励进一步研究湿地洪水长度与其他系统中无脊椎动物密度之间的关系。