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Metals and trace elements in giant garter snakes (Thamnophis gigas) from the Sacramento Valley, California, USA

Archives of Environmental Contamination and Toxicology

By:
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DOI: 10.1007/s00244-008-9265-8

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Abstract

The giant garter snake (GGS; Thamnophis gigas) is a federally listed threatened species endemic to wetlands of the Central Valley of California. Habitat destruction has been the main factor in the decline of GGS populations, but the effects of contaminants on this species are unknown. To contribute to the recovery of these snakes, the U.S. Geological Survey (USGS) began studies of the life history and habitat use of GGSs in 1995. During a series of investigations conducted from 1995 to the present, specimens of dead GGSs were opportunistically collected from the Colusa National Wildlife Refuge (CNWR), the Natomas Basin, and other sites in northern California. Whole snakes were stored frozen for potential future analysis. As funding became available, we analyzed tissues of 23 GGSs to determine the concentrations of total mercury (Hg) and other trace elements in livers and concentrations of Hg in brains and tail clips. Mercury concentrations (??g/g, wet weight) ranged from 0.08 to 1.64 in livers, 0.01 to 0.18 in brains, and 0.02 to 0.32 in tail clips. In livers, geometric mean concentrations (??g/g, dry weight) of arsenic (25.7) and chromium (1.02) were higher than most values from studies of other snakes. Mercury concentrations in tail clips were positively correlated with concentrations in livers and brains, with the most significant correlations occurring at the Natomas Basin and when Natomas and CNWR were combined. Results indicate the value of using tail clips as a nonlethal bioindicator of contaminant concentrations. ?? 2008 US Government.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Metals and trace elements in giant garter snakes (Thamnophis gigas) from the Sacramento Valley, California, USA
Series title:
Archives of Environmental Contamination and Toxicology
DOI:
10.1007/s00244-008-9265-8
Volume
56
Issue:
3
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
577
Last page:
587
Number of Pages:
11