Effects of Age, Adipose Percent, and Reproduction on PCB Concentrations and Profiles in an Extreme Fasting North Pacific Marine MammalReportar como inadecuado




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Persistent organic pollutants, including polychlorinated biphenyls PCBs, are widely distributed and detectable far from anthropogenic sources. Northern elephant seals Mirounga angustirostris biannually travel thousands of kilometers to forage in coastal and open-ocean regions of the northeast Pacific Ocean and then return to land where they fast while breeding and molting. Our study examined potential effects of age, adipose percent, and the difference between the breeding and molting fasts on PCB concentrations and congener profiles in blubber and serum of northern elephant seal females. Between 2005 and 2007, we sampled blubber and blood from 58 seals before and after a foraging trip, which were then analyzed for PCBs. Age did not significantly affect total PCB concentrations; however, the proportion of PCB congeners with different numbers of chlorine atoms was significantly affected by age, especially in the outer blubber. Younger adult females had a significantly greater proportion of low-chlorinated PCBs tri-, tetra-, and penta-CBs than older females, with the opposite trend observed for hepta-CBs, indicating that an age-associated process such as parity birth may significantly affect congener profiles. The percent of adipose tissue had a significant relationship with inner blubber PCB concentrations, with the highest mean concentrations observed at the end of the molting fast. These results highlight the importance of sampling across the entire blubber layer when assessing contaminant levels in phocid seals and taking into account the adipose stores and reproductive status of an animal when conducting contaminant research.



Autor: Sarah H. Peterson , Jason L. Hassrick, Anne Lafontaine, Jean-Pierre Thomé, Daniel E. Crocker, Cathy Debier, Daniel P. Costa

Fuente: http://plos.srce.hr/



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