title: Hepatic element concentrations of lesser scaup (Aythya affinis) during spring migration in the upper Midwest.
abstract: High concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (Aythya affinis) population. We evaluated hepatic element concentrations of male and female lesser scaup collected from the upper Midwest (Iowa, Minnesota, North Dakota, and South Dakota) during the 2003 and 2004 spring migrations. We measured concentrations of 24 elements in livers of 117 lesser scaup. We found that only selenium concentrations were at levels (>3.0 μg/g wet weight [ww)]) proposed to adversely affect reproduction. Approximately 49% of females (n = 61) had individual hepatic concentrations >3.0 μg/g ww selenium (Se). Our observed hepatic concentration of Se was similar to that reported in lesser scaup collected from the mid-continental United States but less than Se concentrations reported from the Great Lakes region. We found that the liver cadmium (Cd) concentration for males was significantly higher than that for females. Gender differences in hepatic Cd concentrations have not been previously reported for lesser scaup, but Cd is known to have negative impacts on male reproduction. Our results indicate that lesser scaup migrating through the upper Midwest in spring have elevated Se levels and that males carry a significantly greater Cd burden than females. Moreover, elemental concentrations might be high enough to affect reproduction in both male and female lesser scaup, but controlled laboratory studies are needed to adequately assess the effects of Se and Cd on lesser scaup reproduction.
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, 2764 Vet Med, Ames, IA 50011-1250, USA. apillatz@iastate.edu
authors.forename: Angela E
authors.initials: AE
authors.lastname: Pillatzki
authors.forename: Regg D
authors.initials: RD
authors.lastname: Neiger
authors.forename: Steven R
authors.initials: SR
authors.lastname: Chipps
authors.forename: Kenneth F
authors.initials: KF
authors.lastname: Higgins
authors.forename: Nancy
authors.initials: N
authors.lastname: Thiex
authors.forename: Alan D
authors.initials: AD
authors.lastname: Afton
mesh_terms: D025041:Animal Migration; D000818:Animals; D002104:Cadmium / Q000378:metabolism; D018011:Chalcogens / Q000378:metabolism*; D004372:Ducks / Q000378:metabolism*; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000378:metabolism*; D005260:Female; D008099:Liver / Q000378:metabolism; D008297:Male; D008670:Metals / Q000378:metabolism*; D015146:Midwestern United States; D008903:Minerals / Q000378:metabolism*; D012621:Seasons; D012643:Selenium / Q000378:metabolism
chemical_list: D018011:Chalcogens; D004785:Environmental Pollutants; D008670:Metals; D008903:Minerals; D002104:Cadmium; D012643:Selenium