Organic halogenated contaminants in mother–fetus pairs of harbor seals (Phoca vitulina richardii) from Alaska, 2000–2002

Abstract

This study measured organochlorine pesticides (OCPs) including hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), heptachlor and dichlorodiphenyltrichloroethanes (DDTs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and polybrominated diphenyl ethers (PBDEs) in tissues of six mother–fetus pairs of harbor seals that were hunted for subsistence in Alaska waters of the Northern Pacific Ocean. These data suggest that significant amounts of these contaminants were transferred from mother harbor seals to fetuses during pregnancy and distributed among fetal organs. The tissue distribution depended on the chemical groups, the specific compounds in the groups and the target organs. Concentration profiles of ΣOCPs, ΣPCBs, ΣPCNs and ΣPBDEs were remarkably similar among maternal blubber, liver, and placenta, fetal blubber, and liver (except for HCHs), possibly indicating that the placenta did not serve as a barrier for all of the compounds analyzed. DDTs, HCB, HCHs, PCBs and PBDEs could penetrate the placenta and accumulate in the blubber of the fetus in utero, while HCHs, PCBs and PBDEs penetrated the placenta and accumulated more preferentially in the fetal liver than in the fetal brain in comparison with DDTs and HCB. Heptachlor and PCNs penetrated the placenta and accumulated in the fetal liver and brain instead of fetal blubber. Similar maternal transfer trends for OCPs, PCBs, PCNs and PBDEs were shown by fetal to maternal (FM) blubber ratios and FM liver ratios. Prenatal transfer of these toxic contaminants from mothers to fetus presumably through the placenta may pose health risks to the fetus during development.

Maternal transfer of organohalogenated compounds in sharks and stingrays

“…This aspect of pollutant transfer has received comparatively less attention than biomagnification, although there have been a considerable number of studies regarding mammalian species (e.g. humans, marine mammals) dealing with body burdens of POPs in offspring (Soechitram et al, 2004;Greig et al, 2007;Vanden Berghe et al, 2012;Wang et al, 2012;Mori et al, 2014). Results for several contaminant classes have suggested a difference between prenatal maternal transfer (i.e.…”

Urinary glucocorticoids in harbour seal (Phoca vitulina) pups during rehabilitation

“…(Laane et al, 2013; Weirup et al, 2013). POP contaminants in maternal tissues may be transferred to the foetus, posing health risks during development (Wang et al 2012).…”

Harbour Seals: Population Structure, Status, and Threats in a Rapidly Changing Environment

“…Populations in the Bering Sea and Aleutian Islands were considered stable in the 1960s and 1970s [57][58][59]; however, surveys from the late 1990s documented precipitous declines [57,59,60]. Declines also occurred in the Gulf of Alaska [60][61][62][63]; however, more recent data suggests that some declines may have lessened [60,64]. In Glacier Bay, a tidewater glacier fjord and marine protected area in southeastern Alaska, precipitous declines in the number of harbour seals have occurred over the last 26 years [65][66][67].…”