Cyanobacterial survival following their release in water from major headwaters reservoirs was compared in five New South Wales rivers. Under low flow conditions, cyanobacterial presence disappeared rapidly with distance downstream in the Cudgegong and Hunter Rivers, whereas the other three rivers were contaminated for at least 300 km. Cyanobacterial survival is likely to be impacted by the geomorphology of each river, especially the extent of gravel riffle reaches (cells striking rocks can destroy them) and by the different turbulent flow conditions it produces within each. Flow conditions at gauging stations were used to estimate the turbulent strain rate experienced by suspended cyanobacteria. These indicate average turbulent strain rates in the Cudgegong and Hunter Rivers can be above 33 and 83 s⁻¹ while for the Murray, Edward and Macquarie Rivers average strain rate was estimated to be less than 30 s⁻¹. These turbulent strain rate estimates are substantially above published thresholds of approximately 2 s⁻¹ for impacts indicated from laboratory tests. Estimates of strain rate were correlated with changes in cyanobacterial biovolume at stations along the rivers. These measurements indicate a weak but significant negative linear relationship between average strain rate and change in cyanobacterial biomass. River management often involves releasing cold deep water with low cyanobacterial presence from these reservoirs, leading to ecological impacts from cold water pollution downstream. The pollution may be avoided if cyanobacteria die off rapidly downstream of the reservoir, allowing surface water to be released instead. However high concentrations of soluble cyanotoxins may remain even after the cyanobacterial cells have been destroyed. The geomorphology of the river (length of riffle reaches) is an important consideration for river management during cyanobacterial blooms in headwater reservoirs.

在新南威尔士州的五条河流中，比较了蓝藻从主要源头水库释放到水中后的蓝细菌存活率。在低流量条件下，Cudgegong河和Hunter河中的下游，随着距离的增加，蓝细菌的存在迅速消失，而其他三条河被污染了至少300 km。蓝藻的存活可能会受到每条河的地貌的影响，尤其是碎石浅滩的延伸范围（撞击岩石的细胞会破坏它们）以及河流中产生的不同湍流条件。测量站的流动条件用于估计悬浮蓝细菌所经历的湍流应变率。这些表明卡吉贡河和亨特河的平均湍流应变率可以高于33和83 s ^-1而对于默里河，爱德华河和麦夸里河，平均应变率估计小于30 s ^-1。这些湍流应变率估计值大大高于已发布的大约2 s ^-1的阈值实验室测试表明的影响。应变率的估计与沿河站的蓝藻生物量的变化相关。这些测量结果表明，平均应变率与蓝细菌生物量变化之间存在弱但显着的负线性关系。河流管理通常涉及从这些水库中释放出低蓝藻含量的冷深水，从而导致下游冷水污染对生态的影响。如果蓝细菌在水库下游迅速消失，可以释放地表水，则可以避免污染。然而，即使在破坏了蓝细菌细胞之后，仍可能保留高浓度的可溶性蓝毒素。