Time-scale toxic effects in aquatic ecosystems

Although the general effects of stormwater on receiving systems are well described, the relationship between loading/concentration changes during stormwater runoff events and time-scale toxicity, which would support improved modeling and prediction of stormwater effects, is poorly defined. In fact, there are few studies that clearly assess the effects of episodic change in contaminant concentration on individuals, populations, or communities of organisms. To effectively assess these time-scale effects, it is necessary to connect multiple factors, including physical, chemical and biological/ecological characteristics of receiving systems and their watersheds conditions, which affect receiving system biota. The interactions between flow and toxic contaminant concentration in stormwater runoff events, and the measurement of toxic effect is the focus of this paper.