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Effects of contaminants on reproductive success of aquatic birds nesting at Edwards Air Force Base, California

Archives of Environmental Contamination and Toxicology

By:
, , and
DOI: 10.1007/s00244-005-0226-1

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Abstract

Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may indicate the potential for negative effects on avian populations. From 1996 to 1999, we conducted studies at the Piute Ponds area of EAFB to evaluate the impacts of contaminants on nesting birds. Avian reproduction was evaluated in 1999. Eggs were collected for chemical analyses in 1996 and 1999, and African clawed frogs (Xenopus laevis), a likely food source, were collected for chemical analyses in 1998. Avian species occupying the higher trophic levels-black-crowned night-heron (Nycticorax nycticorax), white-faced ibis (Plegadis chihi), and American avocet (Recurvirostra americana)-generally bioaccumulated higher concentrations of contaminants in their eggs. Reproductive success and egg hatchability of night-herons and white-faced ibises in the Piute Ponds were similar to results observed at other western colonies. Deformities were observed in only one embryo in this study, but concentrations of contaminants evaluated in this ibis embryo were considered insufficient to have caused the deformities. Because clawed frogs, a primary prey item for night-herons at Piute Ponds, had no detectable levels of any OCs, it is likely that OCs found in night-heron eggs were acquired from the wintering grounds rather than from EAFB. The presence of isomers of dichlorodiphenyltrichloroethane (DDT) in ibis eggs indicated recent exposure, but invertebrates used for food by ibises were not sampled at Piute Ponds, and conclusions about the source of OCs in ibis eggs could not be made. Concentrations of contaminants in random and failed eggs of individual species were not different, and we concluded that contaminants did not cause the observed egg failures. ?? 2006 Springer Science+Business Media, Inc.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Effects of contaminants on reproductive success of aquatic birds nesting at Edwards Air Force Base, California
Series title:
Archives of Environmental Contamination and Toxicology
DOI:
10.1007/s00244-005-0226-1
Volume
51
Issue:
4
Year Published:
2006
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Archives of Environmental Contamination and Toxicology
First page:
711
Last page:
719
Number of Pages:
9