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See detailBlood dynamics of mercury and selenium in northern elephant seals during the lactation period
Habran, Sarah ULg; Debier, Cathy; Crocker, Dan et al

in Environmental Pollution (2011), 159(10), 2523-2529

The effects of reproduction and maternal investment (i.e., milk transfer) on trace element levels remain poorly understood in marine mammals. We examined the blood dynamics of mercury (Hg) and selenium ... [more ▼]

The effects of reproduction and maternal investment (i.e., milk transfer) on trace element levels remain poorly understood in marine mammals. We examined the blood dynamics of mercury (Hg) and selenium (Se) during lactation in the northern elephant seal (Mirounga angustirostris), a top predator from the North Pacific Ocean. Total Hg and Se levels were measured in whole blood and milk of 10 mother-pup pairs on days 5 and 22 of lactation. Both Hg and Se were transferred to offspring through the milk. Results suggested that the maternal transfer of Se was prominent during lactation, whereas the Hg transfer was larger during gestation. The lactation period affected Hg and Se levels in the blood of elephant seal mothers and pups. Physiological processes and their relationship to body condition should be considered carefully when interpreting trace element levels in the framework of biomonitoring. [less ▲]

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Peer Reviewed
See detailMaternal transfer of trace metals to offspring in northern elephant seals
Habran, Sarah ULg; Debier, Cathy; Crocker, Daniel et al

Poster (2008, October 30)

Detailed reference viewed: 40 (13 ULg)
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See detailLactation effect on the trace element dynamics in northern elephant seals (Mirounga angustirostris)
Habran, Sarah ULg; Debier, Cathy; Lepoint, Gilles ULg et al

Conference (2007, November 30)

Northern elephant seals, Mirounga angustirostris, are exceptional mammals: females fast entirely during nursing while their pups may quadruple in weight over the 25-day suckling period. Females thus lose ... [more ▼]

Northern elephant seals, Mirounga angustirostris, are exceptional mammals: females fast entirely during nursing while their pups may quadruple in weight over the 25-day suckling period. Females thus lose approximately a third of body mass and produce energy-rich milk with a high fat content. Stable carbon and nitrogen isotope ratios (d13C and d15N used as diet markers) and total mercury concentrations (Hg) were measured in tissues (blood cells, serum, full blood, milk and blubber) from 20 mother-pup pairs on days 4 and 21 of lactation. A systematic difference was observed between isotopic values in blood cells and serum of the mothers, linked to diet and distinct biochemical composition between blood components. d13C differed between inner and outer blubber layers and were similar between inner blubber and milk. High Hg concentrations (up to 350 ng.g-1ww at the beginning of lactation) were found in the blood of mother elephant seals linked to their high d15N values in blood cells. Hg transfer through placenta and milk was observed between mothers and pups. A significant increase of blood Hg concentration in mothers (+285 ng.g-1ww) and a decrease in pups (-93 ng.g-1ww) were observed between days 4 and 21 of lactation. Both processes were explained by a remobilization of proteins and lipids during fasting and milk production in mothers and by a dilution of Hg in pups due to their high mass increase during this period. This study confirms that lactation modifies stable nitrogen isotope ratios in tissues, as well as mercury levels in blood from mothers and pups, and highlights the existence of a transplacental and transmammary transfer of mercury in northern elephant seals. Therefore, physiological processes and body condition should be considered carefully when interpreting stable isotope ratios and Hg concentrations in the framework of biomonitoring. [less ▲]

Detailed reference viewed: 83 (21 ULg)
Peer Reviewed
See detailLactation effect on stable isotope ratios and mercury levels in the blood of northern elephant seals
Habran, Sarah ULg; Debier, Cathy; Lepoint, Gilles ULg et al

Poster (2006, October 27)

Female northern elephant seals, Mirounga angustirostris, fast entirely during nursing while their pups may quadruple in weight over the 25-day suckling period. Stable carbon and nitrogen isotope ratios ... [more ▼]

Female northern elephant seals, Mirounga angustirostris, fast entirely during nursing while their pups may quadruple in weight over the 25-day suckling period. Stable carbon and nitrogen isotope ratios (d13C and d15N used as diet markers) and total mercury concentrations (Hg) were measured in tissues (blood cells, serum, full blood, milk and blubber) from 20 mother-pup pairs on day 4 and 21 of lactation. A systematic difference was observed between isotopic values in blood cells and serum of the mothers, linked to diet and distinct biochemical composition between blood components. d13C differed between inner and outer blubber layers and were similar between inner blubber and milk. High Hg concentrations (up to 350 ng.g-1 ww at the beginning of lactation) were found in the blood of mother elephant seals linked to their high d15N values in blood cells. Hg transfer through placenta and milk was observed between mothers and pups. A significant increase of blood Hg concentration in mothers (+285 ng.g-1ww) and a decrease in pups (-93 ng.g-1ww) were observed between days 4 and 21 of lactation. Both processes were explained by a remobilization of proteins and lipids during fasting and milk production in mothers and by a dilution of Hg in pups due to their high mass increase during this period. To conclude, physiological processes and body condition should be considered carefully when interpreting stable isotope ratios and Hg concentrations in the framework of biomonitoring. [less ▲]

Detailed reference viewed: 71 (18 ULg)