Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Oct 15;110(42):16922-6.
doi: 10.1073/pnas.1311418110. Epub 2013 Sep 16.

Blue whale earplug reveals lifetime contaminant exposure and hormone profiles

Stephen J Trumble  1 , Eleanor M Robinson, Michelle Berman-Kowalewski, Charles W Potter, Sascha Usenko
Affiliations

Blue whale earplug reveals lifetime contaminant exposure and hormone profiles

Stephen J Trumble et al. Proc Natl Acad Sci U S A. .

Abstract

Lifetime contaminant and hormonal profiles have been reconstructed for an individual male blue whale (Balaenoptera musculus, Linnaeus 1758) using the earplug as a natural aging matrix that is also capable of archiving and preserving lipophilic compounds. These unprecedented lifetime profiles (i.e., birth to death) were reconstructed with a 6-mo resolution for a wide range of analytes including cortisol (stress hormone), testosterone (developmental hormone), organic contaminants (e.g., pesticides and flame retardants), and mercury. Cortisol lifetime profiles revealed a doubling of cortisol levels over baseline. Testosterone profiles suggest this male blue whale reached sexual maturity at approximately 10 y of age, which corresponds well with and improves on previous estimates. Early periods of the reconstructed contaminant profiles for pesticides (such as dichlorodiphenyltrichloroethanes and chlordanes), polychlorinated biphenyls, and polybrominated diphenyl ethers demonstrate significant maternal transfer occurred at 0-12 mo. The total lifetime organic contaminant burden measured between the earplug (sum of contaminants in laminae layers) and blubber samples from the same organism were similar. Total mercury profiles revealed reduced maternal transfer and two distinct pulse events compared with organic contaminants. The use of a whale earplug to reconstruct lifetime chemical profiles will allow for a more comprehensive examination of stress, development, and contaminant exposure, as well as improve the assessment of contaminant use/emission, environmental noise, ship traffic, and climate change on these important marine sentinels.

Keywords: cerumen; cetaceans; persistent organic pollutants.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Illustration of a blue whale earplug. (A) Schematic diagram showing the location of the earplug within the ear canal: (a) whale skull, (b) tympanic bulla, (c) pars flaccida/tympanic membrane (“glove finger”), (d) cerumen (earplug), (e) external auditory meatus, (f) auditory canal, (g) muscle tissue, (h) blubber tissue, and (i) epidermis. (B) Extracted blue whale earplug; total length 25.4 cm. (C) Earplug longitudinal cross-section. (D) View (20×) of earplug cross-section showing discrete laminae.
Fig. 2.
Fig. 2.
Reconstructed chemical profiles measured in a blue whale earplug. Each measurement reflects the mean concentration during lamina production. (A) Cortisol levels increased with age, whereas testosterone peaked at 120 mo (∼100× increase). (B) PBDE 47 profiles demonstrate considerable depuration from mother during periods of early development. (C) Historic-use pesticide profiles of DDT and metabolites and nonachlor compounds. (D) PCB profiles showed trends similar to the other pesticides with the highest levels measured in the first lamina. (E) Total mercury and organic contaminant deposition accumulation rate. (F) Life span mercury profile shows two unique peaks at 60–72 and 120–126 mo.
Fig. 3.
Fig. 3.
Male blue whale blubber (left axis) and earplug (right axis) contaminant profiles. Blubber was sampled near muscle blubber interface and compared with the lamina corresponding to 72–78 mo in the earplug, which represents a midpoint in the organism lifespan.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Reilly SB, et al. 2008. Balaenoptera musculus. International Union for Conservation of Nature 2012. IUCN Red List of Threatened Species. Version 2012.2. Available at www.iucnredlist.org. Accessed June 7, 2013.
    1. Clapham PJ, Young SB, Brownell RL. Baleen whales: Conservation issues and the status of the most endangered populations. Mammal Rev. 1999;29(1):35–60.
    1. Kjeld JM, Ólafsson O, Víkingsson GA, Sigurjónsson J. Sex hormones and reproductive status of the North Atlantic fin whales (Balaenoptera physalus) during the feeding season. Aquat Mamm. 2006;32(1):75–84.
    1. Hogg CJ, et al. Determination of steroid hormones in whale blow: It is possible. Mar Mamm Sci. 2009;25(3):605–618.
    1. Moore MJ, van der Hoop JM. The painful side of trap and fixed net fisheries: Chronic entanglement of large whales. J Mar Biol. 2012;2012:1–4.

Publication types