Examining the relationships between blubber steroid hormones and persistent organic pollutants in common bottlenose dolphins

Details

• Journal Title:
  Environmental Pollution
• Personal Author:
  Galligan, Thomas M. ; Balmer, Brian C. ; Schwacke, Lori H. ; Bolton, Jennie L. ; Quigley, Brian M. ; Rosel, Patricia E. ; Ylitalo, Gina M. ; Boggs, Ashley S.P.
• NOAA Program & Office:
  NMFS (National Marine Fisheries Service) ; SEFSC (Southeast Fisheries Science Center) ; NWFSC (Northwest Fisheries Science Center)
• Description:
  Odontocete cetaceans bioaccumulate high concentrations of endocrine disrupting persistent organic pollutants (POPs), including dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyltrichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) – collectively DDTs – but few studies have explored DDTs-mediated endocrine disruption in cetaceans. Herein, we use remotely collected blubber biopsies from common bottlenose dolphins (Tursiops truncatus) inhabiting a site with high localized DDTs contamination to study the relationships between DDTs exposure and steroid hormone homeostasis in cetaceans. We quantified blubber steroid hormone concentrations by liquid chromatography-tandem mass spectrometry and blubber POP concentrations by gas chromatography-mass spectrometry. We detected six steroid hormones in blubber, including progesterone (P4), 17-hydroxyprogesterone (17OHP4), androstenedione (AE), testosterone (T), cortisol (F), and cortisone (E). Sampled dolphins (n = 62) exhibited exposure to DDT, DDE, DDD, chlordanes (CHLDs), mirex, dieldrin, hexachlorobenzene, polychlorinated biphenyls (PCBs), and brominated diphenyl ethers (BDEs). Using principal components analysis (PCA), we determined that blubber DDTs primarily loaded to the first principal component (PC1) explaining 81.6% of the total variance in POP exposure, while the remaining POPs primarily loaded to the PC2 (10.4% of variance). PC1 scores were negatively correlated with blubber T in males and blubber F in females, suggesting that exposure to DDTs impacted androgen and corticosteroid homeostasis. These conclusions were further supported by observed negative correlations between T and o,p’-DDE, o,p’-DDD, and p,p’-DDD in males sampled in the fall, and between F and the six individual DDTs and ∑6DDTs in females. Overall, these results suggest that POP-mediated endocrine disruption may have occurred in this stock of dolphins, which could negatively impact their health and fitness. However, this study relied on uncontrolled incidental exposures, making it impossible to establish a causal relationship between DDTs exposure and endocrine effects. Importantly, this study demonstrates that remotely collected blubber biopsies are a useful matrix for studying endocrine disruption in marine mammals.
• Keywords:
  Blubber Bottlenose Dolphin DDT (Insecticide) Steroid Hormones Bottlenose Dolphin Steroid Hormones Endocrine Disruption Marine Mammal Persistent Organic Pollutants (POPs)
• Source:
  Environmental Pollution 249 (2019) 982e991
• DOI:
  https://doi.org/10.1016/j.envpol.2019.03.083
• Document Type:
  Journal Article
• Rights Information:
  Accepted Manuscript
• Rights Statement:
  The NOAA IR provides access to this content under the authority of the government's retained license to distribute publications and data resulting from federal funding. While users may legally access this content, the copyright owners retain rights that govern the reproduction, redistribution, and re-use of this work. The user is solely responsible for complying with applicable copyright law.
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:89d24c332f37450200c0f662c41488e04b9864e5cca7c0ef94c6ee5d4e47f9375680ea85274857038f3a1cae96af698fe88967817f38a703637415fb2b52f450
• Download URL:
  https://repository.library.noaa.gov/view/noaa/47281/noaa_47281_DS1.pdf
• File Type:
  [PDF - 1.34 MB ]