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Stable metal isotopes reveal copper accumulation and loss dynamics in the freshwater bivalve Corbucula

Environmental Science and Technology

By:
, , ,
DOI: 10.1021/es049432q

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Abstract

Characterization of uptake and loss dynamics is critical to understanding risks associated with contaminant exposure in aquatic animals. Dynamics are especially important in addressing questions such as why coexisting species in nature accumulate different levels of a contaminant. Here we manipulated copper (Cu) stable isotopic ratios (as an alternative to radioisotopes) to describe for the first time Cu dynamics in a freshwater invertebrate, the bivalve Corbicula fluminea. In the laboratory, Corbicula uptake and loss rate constants were determined from an environmentally realistic waterborne exposure to 65Cu (5.7 ??g L-1). That is, we spiked deionized water with Cu that was 99.4% 65Cu. Net tracer uptake was detectable after 1 day and strongly evident after 4 days. Thus, short-term exposures necessary to determine uptake dynamics are feasible with stable isotopes of Cu. In Corbicula, 65Cu depuration was biphasic. An unusually low rate constant of loss (0.0038 d-1) characterized the slow component of efflux, explaining why Corbicula strongly accumulates copper in nature. We incorporated our estimates of rate constants for dissolved 65Cu uptake and physiological efflux into a bioaccumulation model and showed that dietary exposure to Cu is likely an important bioaccumulation pathway for Corbicula.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Stable metal isotopes reveal copper accumulation and loss dynamics in the freshwater bivalve Corbucula
Series title:
Environmental Science and Technology
DOI:
10.1021/es049432q
Volume
38
Issue:
19
Year Published:
2004
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
5002
Last page:
5009
Number of Pages:
8