Burtchett Jade M, Mallin Michael A, Cahoon Lawrence B
Center for Marine Sciences, University of North Carolina Wilmington, Wilmington, NC 28409, USA E-mail:
Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403, USA.
Water Sci Technol. 2017 Jun;75(11-12):2702-2715. doi: 10.2166/wst.2017.170.
A priority for environmental managers is control of stormwater runoff pollution, especially fecal microbial pollution. This research was designed to determine if fecal bacterial grazing by micro-zooplankton is a significant control on fecal bacteria in aquatic best management practices (BMPs); if grazing differs between a wet detention pond and a constructed wetland; and if environmental factors enhance grazing. Both 3-day grazing tests and 24-h dilution assays were used to determine grazing differences between the two types of BMP. Micro-zooplankton grazing was a stronger bacteria removal mechanism in stormwater wetlands rich in aquatic vegetation compared to a standard wet detention pond, although grazing was important in detention ponds as well. Our experiments indicated that the majority of grazers that fed on fecal bacteria were <20 μm in size. Grazing rates were positively correlated with fecal coliform abundance and increased water temperatures. Enumeration of grazers demonstrated that protozoans were significantly more abundant among wetland vegetation than in open water, and open wetland waters contained more flagellates and dinoflagellates than open wet detention pond waters. Grazing on fecal bacteria in BMPs is enhanced by aquatic vegetation, and grazing in aquatic BMPs in warmer climates should be greater than in cooler climates.
环境管理者的一个优先事项是控制雨水径流污染，尤其是粪便微生物污染。本研究旨在确定微型浮游动物对粪便细菌的捕食是否对水生最佳管理实践（BMPs）中的粪便细菌有显著控制作用；湿滞留池和人工湿地之间的捕食情况是否不同；以及环境因素是否会增强捕食作用。采用3天捕食试验和24小时稀释试验来确定两种类型BMP之间的捕食差异。与标准湿滞留池相比，在富含水生植物的雨水湿地中，微型浮游动物的捕食是一种更强的细菌去除机制，尽管捕食在滞留池中也很重要。我们的实验表明，以粪便细菌为食的大多数捕食者的大小小于20μm。捕食率与粪大肠菌群丰度和水温呈正相关。捕食者的计数表明，湿地植被中的原生动物明显比开阔水域中的丰富，开阔的湿地水域中的鞭毛虫和甲藻比开阔的湿滞留池水域中的更多。水生植物会增强对BMPs中粪便细菌的捕食，并且在气候较温暖地区的水生BMPs中的捕食作用应大于气候较凉爽地区。
