Effects of Bromacil, Diuron, Glyphosate, and Sulfometuron-Methyl on Periphyton Assemblages and Rainbow Trout

摘要

This study documents the testing of several common herbicides used by the Oregon Department of Transportation in vegetation management. The project assessed the short- and long-term effects of Roundup, Krovar and Oust on periphyton and rainbow trout. The active ingredient in Roundup is glyphosate; Krovar uses bromacil and diuron; and Oust uses sulfometuron-methyl. Short-term (96 hour) exposure tests used actual road shoulder runoff collected after herbicide application, using a simulated rain and a natural rain event. Long-term exposure tests assessed effects of a 14-day exposure using lab-mixed solutions of deionized lab water and herbicides, individually and in mixture. The data showed that the short-term exposure had no statistically significant effects on periphyton. The short-term exposure reduced survivorship of rainbow trout, but the effects were observed both in treated and untreated runoff; thus the toxicity was likely due to other factors. The long-term exposure tests showed that herbicides, especially Krovar and the mixture of three chemicals, reduced periphyton algal biomass.