Journal
ENVIRONMENTAL POLLUTION
Volume 249, Issue -, Pages 982-991Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.envpol.2019.03.083
Keywords
Bottlenose dolphin; Blubber; DDT; Endocrine disruption; Marine mammal; Steroid hormone
Categories
Funding
- Navy Sea Systems Command, Naval Undersea Warfare Center, Newport Division [N00178-12-D-6974-3]
- NOAA National Ocean Service National Centers for Coastal Ocean Science
- National Marine Mammal Foundation
- NOAA NMFS Southeast Fisheries Science Center
- NOAA NMFS Southeast Regional Office
- NOAA NMFS Northwest Fisheries Science Center
- National Institute of Standards and Technology
- Medical University of South Carolina
- Florida Department of Environmental Protection
- Dolphin Relief and Research
- Gulfarium Marine Adventure Park
- Gulf World Marine Park
- NOAA Fisheries Office of Protected Resources
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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 truncates) 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 (P-4), 17-hydroxyprogesterone (17OHP(4)), 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 Sigma 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. (C) 2019 Elsevier Ltd. All rights reserved.
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