We examined drivers of water quality during 2007–2013 in a region of Lake Ontario influenced by various anthropogenic inputs and natural influences. Nutrient concentrations generally declined from shoreline to offshore, with mean concentrations approaching background after 1 km from shore. N species were an exception to this overall pattern, often with higher concentrations coincident with a mid-nearshore Water Pollution Control Plant outfall (WPCPo). The WPCPo, however, did not appear to be a major contributor to shoreline total phosphorus (TP) or ammonia + ammonium. Shoreline TP variability increased in dry years, while E. coli and conductivity variability increased in wet years. The influence of environmental drivers on water quality differed seasonally. In summer, cross-shore winds causing resuspension appeared to be drivers of elevated nearshore TP and suspended solids (SS), while precipitation, light, and water column stability were related to E. coli. Summer biological activity was evident in higher shoreline total Kjeldhal N contributions and lower NO₃ + NO₂ and dissolved inorganic N. In fall and spring, TP, SS, and conductivity were elevated within 400 m of the shore, suggesting tributary inputs were an important P delivery mechanism to the nearshore in addition to spring resuspension events. Fall, however, represented a transitional period representing a shift from drivers dominant in summer to those in spring. The analytical approach used here reveals generalizable patterns in nearshore water quality and their drivers and may be applicable to other regions where there is a confluence of varying drivers of water quality to a nearshore region.

我们研究了 2007-2013 年间安大略湖地区受各种人为输入和自然影响影响的水质驱动因素。从海岸线到近海，养分浓度普遍下降，平均浓度在离岸 1 公里后接近背景。N 物种是这种整体模式的一个例外，通常与中部近岸水污染控制厂排放口 (WPPCo) 的浓度较高。然而，WPPCo 似乎不是海岸线总磷 (TP) 或氨 + 铵的主要贡献者。干旱年份海岸线 TP 变异性增加，而大肠杆菌和电导率变化在雨年增加。环境驱动因素对水质的影响因季节而异。夏季，引起再悬浮的跨岸风似乎是近岸 TP 和悬浮固体 (SS) 升高的驱动因素，而降水、光和水柱稳定性与大肠杆菌有关。夏季生物活性在较高的海岸线总凯氏氮贡献和较低的 NO ₃  + NO _{2中很明显}和溶解的无机氮。在秋季和春季，TP、SS 和电导率在海岸 400 m 内升高，表明除了春季再悬浮事件之外，支流输入是近岸的重要 P 输送机制。然而，秋季代表了一个过渡时期，代表了从夏季主导的司机向春季主导的转变。这里使用的分析方法揭示了近岸水质及其驱动因素的普遍模式，并且可能适用于其他地区，这些地区存在不同的水质驱动因素与近岸地区的汇合。