Fisheries and Oceans Canada, Gulf Fisheries Center, 343 Université Av., Moncton, New Brunswick, Canada; Canadian Rivers Institute, Department of Biology, University of Prince Edward Island, Charlottetown, Canada.
Canadian Rivers Institute, Department of Biology, University of Prince Edward Island, Charlottetown, Canada; Canadian Rivers Institute, School of Environment, Resources and Sustainability, University of Waterloo, Waterloo, Canada.
Mar Pollut Bull. 2018 Aug;133:261-270. doi: 10.1016/j.marpolbul.2018.05.041. Epub 2018 May 30.
Simple empirical models can sometimes capture salient patterns without sacrificing predictive capacity when compared to more complex models. Herein we examine dissolved oxygen as an indicator of eutrophication status for shallow estuaries. Dissolved oxygen was measured hourly in the upper estuary of 15 watersheds along a nutrient-loading and geographic gradient. Metrics describing hypoxia and supersaturation were devised and then analyzed using multivariate statistics. Results revealed independent responses for hypoxia and supersaturation with hypoxia-related metrics correlating strongly with water residence. A metric integrating hypoxia and supersaturation effectively discriminated between seagrass and algae-dominated habitats and was significantly correlated with both water residence and nitrate-N loading. Chlorophyll, measured bi-weekly, was not correlated with our predictor variables likely because it does not account for benthic production. Over 70% of the variability in hypoxia was explained by water residence and nitrate-N loading indicating that this model can be of use for managers.
简单的经验模型有时可以在不牺牲预测能力的情况下捕捉到显著的模式，与更复杂的模型相比。在这里，我们将溶解氧作为浅水河口富营养化状态的指标进行研究。在营养负荷和地理梯度的影响下，15 个流域的上游河口每小时测量一次溶解氧。设计了描述缺氧和过饱和的指标，然后使用多元统计进行分析。结果表明，缺氧和过饱和有独立的反应，与水停留时间密切相关的缺氧相关指标相关性很强。一个整合缺氧和过饱和的指标有效地区分了海草和藻类占主导地位的栖息地，与水停留时间和硝酸盐-N 负荷显著相关。每两周测量一次的叶绿素与我们的预测变量没有相关性，可能是因为它没有考虑到底栖生物的产量。超过 70%的缺氧变化可以用水停留时间和硝酸盐-N 负荷来解释，这表明该模型对管理者来说是有用的。
