Effect of discharge and habitat type on the occurrence and severity of Didymosphenia geminata mats in the Restigouche River, eastern Canada
Effect of discharge and habitat type on the occurrence and severity of Didymosphenia geminata mats in the Restigouche River, eastern Canada
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流量和生境类型对加拿大东部雷斯蒂古什河双生双体藻垫的发生和严重程度的影响
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
N. Bergeron
中科院分区：
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作者：
C. Gillis;S. Dugdale;N. Bergeron
自2006年以来，加拿大东部的Restigouche河流域一直受到垫状硅藻Didymosphenia geminata的滋扰性生长的影响。2010年，鉴于这一事件对当地大西洋鲑鱼渔业的潜在影响，我们建立了一个志愿者监测网络，以评估D。双子叶垫严重度内的分水岭。在6个夏季的监测过程中，对D. Restigouche河流域的20个子流域报告了双子垫的严重程度。绘制了观测图，以说明D的年度严重程度。整个流域的双子叶垫。然后从该数据集中提取样本，以评估严重程度的空间和时间变异性。在到达尺度上，D.与任何其他河流生境类型相比，双子叶植物主要出现在浅滩中。在流域尺度上，双样本Kolmogorov-Smirnov检验强调了最大泉水流量对年平均D的显著影响。geminata mat severity，表明当春季最大流量较高时，D.随后几个月的双子垫明显较低。此外，最大春季流量解释了71%的变异，每年垫严重程度。这项研究有助于理解垫严重度动态，并说明了志愿者监测网络研究复杂的生态系统动态的价值。
Since 2006, the Restigouche River watershed, eastern Canada, has been affected by nuisance growths of the mat‐forming diatom, Didymosphenia geminata. In 2010, in view of the potential impacts of this alga on the local Atlantic salmon fishery, we created a volunteer monitoring network to assess D. geminata mat severity within the watershed. Over the course of 6 monitoring summers, more than 1,200 observations of D. geminata mat severity were reported in 20 subwatersheds of the Restigouche River basin. Observations were mapped to illustrate the yearly severity of D. geminata mats throughout the watershed. Metrics were then extracted from this dataset to assess the spatial and temporal variability of mat severity. At the reach scale, D. geminata occurrence was predominantly found in riffles compared to any other river habitat type. At the watershed scale, a two‐sample Kolmogorov–Smirnov test highlighted a significant effect of maximum spring discharge on mean annual D. geminata mat severity, indicating that when maximum spring discharge is high, severity of D. geminata mats in the following months is significantly lower. Additionally, maximum spring discharge explained 71% of the variability in annual mat severity. This study contributes to the understanding of mat severity dynamics and illustrates the value of volunteer monitoring networks for studying complex ecosystem dynamics.