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Rapid changes in small fish mercury concentrations in estuarine wetlands: Implications for wildlife risk and monitoring programs

Environmental Science and Technology

By:
and
DOI: 10.1021/es901400c

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Abstract

Small fish are commonly used to assess mercury (Hg) risk to wildlife and monitor Hg in wetlands. However, limited research has evaluated short-term Hg variability in small fish, which can have important implications for monitoring programs and risk assessment. We conducted a time-series study of Hg concentrations in two small fish species representing benthic (longjaw mudsuckers [Gillichthys mirabilis]) and pelagic (threespine sticklebacks [Gasterosteus aculeatus]) food-webs within three wetland habitats in San Francisco Bay Estuary. We simultaneously monitored prey deliveries, nest initiation, and chick hatching dates of breeding Forster's terns (Sterna forsteri), the most abundant nesting piscivore in the region. Mudsuckers and sticklebacks were the predominant prey fish, comprising 36% and 25% of tern diet, and Hg concentrations averaged (geometric mean ?? SE, ??g/g dw) 0.44 ?? 0.01 and 0.68 ?? 0.03, respectively. Fish Hg concentrations varied substantially over time following a quadratic form in both species, increasing 40% between March and May then decreasing 40% between May and July. Importantly, Forster's terns initiated 68% of nests and 31% of chicks hatched during the period of peak Hg concentrations in prey fish. These results illustrate the importance of short-term temporal variation in small fish Hg concentrations for both Hg monitoring programs and assessing wildlife risk.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Rapid changes in small fish mercury concentrations in estuarine wetlands: Implications for wildlife risk and monitoring programs
Series title:
Environmental Science and Technology
DOI:
10.1021/es901400c
Volume
43
Issue:
22
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental Science and Technology
First page:
8658
Last page:
8664