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Stratification, sex and ontogenetic effects on the lipid and fatty acid profiles in the blubber of sperm whales from Tasmanian waters. J Comp Physiol B 2022; 192:789-804. [PMID: 35939091 DOI: 10.1007/s00360-022-01453-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 05/11/2022] [Accepted: 07/19/2022] [Indexed: 10/15/2022]
Abstract
We examined the differential deposition of lipids according to layer, sex and ontogeny in the blubber of 31 adult sperm whales (n = 22 females, 9 males) and two calves that stranded off the Tasmanian coast from 2002 to 2004. Total lipid (TL) content varied widely across the blubber layers of adults (27-77%). Overall, females had higher TL content than males possibly representing higher energy needs due to reproduction. Higher TL content in the middle layer of adults (69%) suggests this layer may act as an energy reserve. Wax esters (WE) dominated the blubber and were highest in the outer layer of adults and calves, likely providing insulative qualities for this deep-diving odontocete. Triacyclglycerols, an easily mobilized energy source, were highest in the inner layer of females (37.3 ± 13.5%) and calves (32.1 ± 1.8%) compared to males (17.1 ± 8.2%). Monounsaturated fatty acids (MUFA) also dominated the blubber. An increasing gradient from the inner to outer layer reflected an increasing source of endogenously synthesized lipids, whereas an increasing gradient of saturated fatty acids and polyunsaturated fatty acids (PUFA) toward the inner layer reflected an increasing source of dietary lipids. Although body site did not affect lipid profiles, stratification between the outer and more metabolically active inner layers suggests that only using the outer layer may result in an incomplete lipid profile for sperm whales.
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Sun J, Zhang L, Zhou F, Shaw S, Roos A, Berger M, Bäcklin BM, Huang Y, Zheng X, Wang X, Chen D. Hepatic Fatty Acid Profiles Associated with Exposure to Emerging and Legacy Halogenated Contaminants in Two Harbor Seal Populations across the North Atlantic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1830-1840. [PMID: 35068154 DOI: 10.1021/acs.est.1c06512] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Fatty acids (FAs) have been extensively used as indicators of foraging ecology in marine mammals, yet their association with exposure to contaminants has rarely been investigated. The present study provided the first characterization of the relationship between hepatic FA profiles and exposure to a suite of contaminants in a sentinel species─the harbor seal (Phoca vitulina)─from the Gulf of Maine and the south coast of Sweden. FA profiles differed in the two seal populations, and the levels of legacy and alternative brominated flame retardants and polyhalogenated carbazoles were significantly elevated in Maine seals. Correlations between individual FAs and multiple flame retardants (FRs) and poly- and perfluoroalkyl substances (PFASs) were found in seals from both populations. Moreover, several FR and PFAS chemicals were significantly associated with the estimated desaturating enzyme activity inferred from the FA profiles. The ratios of poly to monounsaturated FAs (∑PUFAs/∑MUFAs) and those of unsaturated to saturated FAs (∑UFAs/∑SFAs) were significantly associated with HBBZ, PFHxS, or BDE 47 in seals from Maine and Sweden, whereas ∑n - 6/∑n - 3 PUFAs was significantly associated with BDE 154 and 36-CCZ in Swedish and Maine seals, respectively. Our results suggest the lipid metabolism-disrupting potential of these contaminants in marine mammals and warrant continuous biomonitoring and risk assessment, considering the critical role of PUFAs in vital biological processes.
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Affiliation(s)
- Jiachen Sun
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, CN-510632 Guangzhou, Guangdong, China
| | - Long Zhang
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, CN-510632 Guangzhou, Guangdong, China
| | - Fengli Zhou
- Research Center of Harmful Algae and Marine Biology, Jinan University, CN-510632 Guangzhou, Guangdong, China
| | - Susan Shaw
- Shaw Institute, Blue Hill Research Center, Blue Hill, Maine 04614, United States
| | - Anna Roos
- Department of Contaminant Research and Monitoring, Swedish Museum of Natural History, Box 5007, Stockholm SE-10405, Sweden
| | - Michelle Berger
- Shaw Institute, Blue Hill Research Center, Blue Hill, Maine 04614, United States
| | - Britt-Marie Bäcklin
- Department of Contaminant Research and Monitoring, Swedish Museum of Natural History, Box 5007, Stockholm SE-10405, Sweden
| | - Yichao Huang
- Department of Toxicology, School of Public Health, Anhui Medical University, CN-230032 Hefei, Anhui, China
| | - Xiaoshi Zheng
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, CN-510632 Guangzhou, Guangdong, China
| | - Xiaodong Wang
- Research Center of Harmful Algae and Marine Biology, Jinan University, CN-510632 Guangzhou, Guangdong, China
| | - Da Chen
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, CN-510632 Guangzhou, Guangdong, China
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