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Mercury bioaccumulation and risk to three waterbird foraging guilds is influenced by foraging ecology and breeding stage

Environmental Pollution

By:
, , ,
DOI: 10.1016/j.envpol.2009.03.030

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Abstract

We evaluated mercury (Hg) in five waterbird species representing three foraging guilds in San Francisco Bay, CA. Fish-eating birds (Forster's and Caspian terns) had the highest Hg concentrations in thier tissues, but concentrations in an invertebrate-foraging shorebird (black-necked stilt) were also elevated. Foraging habitat was important for Hg exposure as illustrated by within-guild differences, where species more associated with marshes and salt ponds had higher concentrations than those more associated with open-bay and tidal mudflats. Importantly, Hg concentrations increased with time spent in the estuary. Surf scoter concentrations tripled over six months, whereas Forster's terns showed an up to 5-fold increase between estuary arrival and breeding. Breeding waterbirds were at elevated risk of Hg-induced reproductive impairment, particularly Forster's terns, in which 48% of breeding birds were at high risk due to their Hg??levels. Our results highlight the importance of habitat and exposure timing, in addition to trophic position, on waterbird Hg bioaccumulation and risk.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Mercury bioaccumulation and risk to three waterbird foraging guilds is influenced by foraging ecology and breeding stage
Series title:
Environmental Pollution
DOI:
10.1016/j.envpol.2009.03.030
Volume
157
Issue:
7
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
1993
Last page:
2002
Number of Pages:
10