Dietary mercury exposure to endangered California Clapper Rails in San Francisco Bay

Marine Pollution Bulletin
By: , and 



California Clapper Rails (Rallus longirostris obsoletus) are an endangered waterbird that forage in tidal-marsh habitats that pose risks from mercury exposure. We analyzed total mercury (Hg) in six macro-invertebrate and one fish species representing Clapper Rail diets from four tidal-marshes in San Francisco Bay, California. Mercury concentrations among individual taxa ranged from lowest at Colma Creek (mean range: 0.09–0.2 μg/g dw) to highest at Cogswell (0.2–0.7), Laumeister (0.2–0.9) and Arrowhead Marshes (0.3–1.9). These spatial patterns for Hg matched patterns reported previously in Clapper Rail blood from the same four marshes. Over 25% of eastern mudsnails (Ilyanassa obsolete) and staghorn sculpin (Leptocottus armatus) exceeded dietary Hg concentrations (ww) often associated with avian reproductive impairment. Our results indicate that Hg concentrations vary considerably among tidal-marshes and diet taxa, and Hg concentrations of prey may provide an appropriate proxy for relative exposure risk for Clapper Rails.

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Publication type Article
Publication Subtype Journal Article
Title Dietary mercury exposure to endangered California Clapper Rails in San Francisco Bay
Series title Marine Pollution Bulletin
DOI 10.1016/j.marpolbul.2014.07.009
Volume 86
Issue 1-2
Year Published 2015
Language English
Publisher Pergamon
Publisher location New York, NY
Contributing office(s) San Francisco Bay-Delta, Western Ecological Research Center
Description 7 p.
First page 254
Last page 260
Country United States
State California
Other Geospatial San Francisco Bay
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