Summary

Description

Vernal pools are a unique ephemeral wetland feature of Californias native landscape which has been heavily impacted over the past century by agricultural and urban development. Current estimates of habitat losses in the Central Valley range from 50 to 85 percent of presettlement acreage. While physical effects have been emphasized in most research on vernal pools there are reasons to suspect contaminant impacts may also imperil these isolated and vulnerable ephemeral wetlands. Vernal pools and National Wildlife Refuges often exist within a matrix of agricultural activity in the Central Valley and may receive pesticides and other contaminants through aerial deposition or runoff. Vernal pool water was collected for pesticide analysis from the Sacramento National Wildlife Refuge Complex and the San Luis National Wildlife Refuge Complex representing the northern and southern geography of the Central Valley respectively. Pesticide residues were extracted from the water samples using Solid Phase MicroExtraction SPME and confirmed via gas chromatographymass spectrometry GCMS. Analysis on the GC was run in SCAN mode to simultaneously evaluate multiple analytes. Standards from each pesticide class were used for retention time confirmation and quantification. Concentrations of detected analytes include legacy organochlorines heptachlor, organophosphates diazinon, organonitrogens trifluralin, and a number of pthalates are reported.