PCB concentrations in lake trout (Salvelinus namaycush) are correlated to habitat use and lake characteristics

Document Type

Article

Publication Date

2008

Publication Title

Environmental Science and Technology

Volume

42

Issue

22

First Page

8239

Last Page

8244

Abstract

This study considers the importance of lake trout habitat as a factor determining persistent organochlorine (OC) concentration. Lake trout is a stenothermal, cold water species and sensitive to hypoxia. Thus, factors such as lake depth, thermal stratification, and phosphorus enrichment may determine not only which lakes can support lake trout but may also influence among-lake variability in lake trout population characteristics including bioaccumulation of OCs. A survey of 23 lakes spanning much of the natural latitudinal distribution of lake trout provided a range of lake trout habitat to test the hypothesis that lake trout with greater access to littoral habitat for feeding will have lower concentrations of OCs than lake trout that are more restricted to pelagic habitat. Using the δ13C stable isotope signature in lake trout as an indicator of influence of benthic littoral feeding, we found a negative correlation between lipid-corrected δ13C and ΣPCB concentrations supporting the hypothesis that increasing access to littoral habitat results in lower OCs in lake trout. The prominence of mixotrophic phytoplankton in lakes with more contaminated lake trout indicated the pelagic microbial food web may exacerbate the biomagnification of OCs when lake trout are restricted to pelagic feeding. A model that predicted ΣPCB in lake trout based on lake area and latitude (used as proximate variables for proportion of littoral versus pelagic habitat and accessibility to littoral habitat respectively) explained 73% of the variability in ΣPCBs in lake trout in the 23 lakes surveyed. © 2008 American Chemical Society.

DOI

10.1021/es801218m

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