Water

This document reviews all routes of environmental fate for hydramethylnon (HMN) with an emphasis on its use in controlling red imported fire ants. HMN is an amidinohydrazone insecticide. Chemical name: 5,5-dimethylperhydropyrimidin-2-one 4-trifluromethyl-alpha-(4-trifluoromethylstyryl)-cinnamylidenehydrazon

CALIFORNIA ENVIRONMENTAL PROTECTION AGENCY

In the summer and fall of 2006, the Department of Pesticide Regulation (DPR) sampled water and sediment from 23 marinas to assess the geographical scope and severity of pollution stemming from the use of antifouling paint (AFP) pesticides in California. Copper, zinc, Irgarol, M1 (the primary breakdown product of Irgarol), and aquatic toxicity were selected as potential indicators of AFP pollution. The highest dissolved copper concentrations were observed in larger salt water marinas along California’s Central and South Coast, the lowest were seen in freshwater lake marinas. Copper and zinc concentrations were almost always higher in the marinas than in the adjacent local reference sites, indicating that significant sources of metals existed in the marinas. Concentrations of zinc never exceeded California’s water quality standards. In contrast, concentrations of dissolved copper in salt and brackish water marinas were frequently above California water quality standards established for the protection of aquatic life. Developmental toxicity tests on the copper-sensitive embryo of the mussel Mytilus galloprovincialis were conducted on 47 marina water samples. Eight of these samples showed a statistically significant toxic response and copper was the likely cause of the toxicity. Several copper toxicity models that account for copper bioavailability to aquatic organisms were used to predict toxicity for the 517 samples for which sitespecifi

A Comparison Study of the Proper use of Hester-Dendy ® Samplers to Achieve Maximum Diversity and Population Size of Benthic

Abstract Lotic waters within the California Central Valley have been greatly altered to accommodate urban and agricultural development. Physical habitat (aquatic vegetation and stream substrate) is often reduced or removed completely, greatly impacting aquatic organisms within the stream. One method of examining a benthic macroinvertebrate (BMI) community in an impaired watershed is to create an artificial substrate for macroinvertebrate colonization. In order to determine maximum diversity and population size obtainable using artificial substrate samplers, proper placement and duration within a stream system should be examined first. The objective of this study was to compare taxa richness and abundance of BMI populations when using Hester-Dendy ® (HD) artificial substrate samplers placed at various in-stream locations and for various lengths of time. Samplers were placed at three in-stream locations (top, bottom and vegetation) at three sites within the Sacramento Valley ecoregion. We found no significant difference in BMI abundance or taxa richness between the locations (p=0.097 and p=0.272, respectively). Of the two deployment periods (6 weeks and 4 weeks) we found no significant difference in BMI abundance or taxa richness between the periods (p = 0.848 and p = 0.306, respectively). Since no difference was seen between locations or deployment time, these results suggest that the most efficient way to use H-D samplers is with the easiest placement and shortest deployment. Acknowledgment ii We would like to thank the following environmental monitoring personnel who assisted with sample collection during the study, Milanka Ilic and Michael Mamola. Their tireless efforts allow us to report the data presented here. Thanks also to the Bidwell Institute o

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This document reviews all routes of environmental fate for imidacloprid under field conditions for its potential use in controlling the glassy-winged sharpshooter. Imidacloprid is a chloronicotinoid insecticide. Chemical name: 1-[(6-chloro-3pyridinyl) methyl]-N-nitro-2-imidazolidinimine)