http://pubs.acs.org/doi/abs/10.1021/acs.est.6b00825
Modulation in Persistent
Organic Pollutant Concentration and Profile by Prey Availability and
Reproductive Status in Southern Resident Killer Whale Scat Samples.
Lundin JI, Ylitalo GM,
Booth RK, Anulacion B, Hempelmann JA, Parsons KM, Giles DA, Seely EA, Hanson
MB, Emmons CK, Wasser SK.
Environ Sci Technol., 2016, 50 (12), pp 6506–6516
Abstract. Persistent organic pollutants (POPs), specifically PCBs, PBDEs, and
DDTs, in the marine environment are well documented, however
accumulation and mobilization patterns at the top of the food-web are
poorly understood. This study broadens the understanding of POPs in the
endangered Southern Resident killer whale population by addressing
modulation by prey availability and reproductive status, along with
endocrine disrupting effects. A total of 140 killer whale scat samples
collected from 54 unique whales across a 4 year sampling period
(2010–2013) were analyzed for concentrations of POPs. Toxicant measures
were linked to pod, age, and birth order in genotyped individuals, prey
abundance using open-source test fishery data, and pregnancy status
based on hormone indices from the same sample. Toxicant concentrations
were highest and had the greatest potential for toxicity when prey
abundance was the lowest. In addition, these toxicants were likely from
endogenous lipid stores. Bioaccumulation of POPs increased with age,
with the exception of presumed nulliparous females. The exceptional
pattern may be explained by females experiencing unobserved neonatal
loss. Transfer of POPs through mobilization of endogenous lipid stores
during lactation was highest for first-borns with diminished transfer to
subsequent calves. Contrary to expectation, POP concentrations did not
demonstrate an associated disruption of thyroid hormone, although this
association may have been masked by impacts of prey abundance on thyroid
hormone concentrations. The noninvasive method for measuring POP
concentrations in killer whales through scat employed in this study may
improve toxicant monitoring in the marine environment and promote
conservation efforts.