Mercury correlates with altered corticosterone but not testosterone or estradiol concentrations in common loons

Ecotoxicology and Environmental Safety
By: , and 

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Abstract

We investigated the relation between environmental mercury exposure and corticosterone concentrations in free-living adult common loons (Gavia immer). We determined blood and feather mercury concentrations and compared them to testosterone, estradiol, and stress-induced plasma corticosterone concentrations. Although neither testosterone nor estradiol correlated with Hg levels, there was a robust positive relation between blood Hg and stress-induced corticosterone concentrations in males, but not in females. The lack of an effect in females may have been due to overall less contamination in females. There were no significant correlations between feather Hg and stress-induced corticosterone in either sex. To help determine whether Hg had a causal effect on corticosterone, we investigated the impact of experimental Hg intake on the corticosterone stress response in captive juvenile loons. Juveniles were subjected to three different feeding regimes: 0, 0.4 and 1.2 μg Hg (as MeHgCL)/g wet weight (ww) fish. We then measured baseline and 30 min post-solitary confinement stressor corticosterone concentrations. The Hg fed chicks exhibited a decreased ability to mount a stress response. From these data, we conclude that Hg contamination does appear to alter the corticosterone response to stress, but not in a consistent predictable pattern. Regardless of the direction of change, however, exposure to mercury contamination and the resulting impact on the corticosterone stress response in common loons may substantially impact health, fitness and survival.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Mercury correlates with altered corticosterone but not testosterone or estradiol concentrations in common loons
Series title Ecotoxicology and Environmental Safety
DOI 10.1016/j.ecoenv.2017.04.030
Volume 142
Year Published 2017
Language English
Publisher Elsevier
Contributing office(s) Upper Midwest Environmental Sciences Center
Description 7 p.
First page 348
Last page 354