Birds of Indian Subcontinent

Selenium in Aquatic Birds from Central California

Publication Type:Journal Article
Year of Publication:1997
Authors:Paveglio, FL, Kilbride, KM, Bunck, CM
Journal:The Journal of Wildlife Management
Date Published:1997
ISBN Number:0022541X
Keywords:Anas, Anas acuta, Anas clypeata, Anas platyrhynchos, Anatidae, Fulica, Fulica americana, Fulica atra, Himantopus, Himantopus himantopus, Himantopus mexicanus, Rallidae, Recurvirostridae
Abstract:Subsurface agricultural drainwater used for wetland management has resulted in selenium (Se) contamination of aquatic bird food chains in central California. After freshwater replaced agricultural drainage water during autumn 1985, Se concentrations in mallards (Anas platyrhynchos), northern shovelers (A. clypeata), northern pintails (A. acuta), American coots (Fulica americana), and black-necked stilts (Himantopus mexicanus) collected from the Grassland Water District (GWD) of California declined from 1986 to 1988 (Paveglio et al. 1992); however, Se concentrations were still above levels associated with reproductive impairment in laboratory and field studies. Consequently, we conducted follow-up collections from the GWD during 1989 and 1994 to determine Se concentrations in aquatic birds after long-term use of freshwater for wetland management. As was found during 1986-88, Se concentrations were higher for birds from the South Grasslands, which historically received more undiluted drainage water compared with the North. Although Se concentrations were lower in 1994 compared with 1986 for aquatic birds (except pintails from the North Grasslands), values generally remained stable or declined slightly from 1988 to 1994. After 9 years of freshwater management of the Grasslands, liver Se concentrations in some wintering birds still were above concentrations associated with impaired reproduction in laboratory and field studies. Under our adaptive management strategy, an additional 1-13 years from 1994 are projected for mallards, shovelers, and stilts from the North and South Grasslands and coots from the South Grasslands to reach background Se concentrations in liver (5.5 ppm dry mass [DM]). In contrast, only an additional 2-7 years from 1994 of freshwater management will be required for stilts and shovelers in the South Grasslands to reduce Se liver concentrations below the threshold associated with reproductive impairment (9 ppm DM). We recommend that freshwater flows to arid wetlands be restored and use of agricultural drainage water for management or disposal in arid wetlands be discontinued.
Short Title:The Journal of Wildlife Management
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith