Data from: Foraging and fasting can influence contaminant concentrations in animals: an example with mercury contamination in a free-ranging marine mammal

• Main Authors: Peterson, Sarah H., Ackerman, Joshua T., Crocker, Daniel E., Costa, Daniel P.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2018
• Subjects: Bioaccumulation; phocid; top predator; Mirounga angustirostris; body condition; Elephant Seals
• Online Access: https://doi.org/10.5061/dryad.q0t6b

Large fluctuations in animal body mass in relation to life-history events can influence contaminant concentrations and toxicological risk. We quantified mercury concentrations in adult northern elephant seals (Mirounga angustirostris) before and after lengthy at sea foraging trips (n = 89) or fasting periods on land (n = 27), and showed that mercury concentrations in blood and muscle changed in response to these events. The highest blood mercury concentrations were observed after the breeding fast, whereas the highest muscle mercury concentrations were observed when seals returned to land to moult. Mean female blood mercury concentrations decreased by 30% across each of the two annual foraging trips, demonstrating a foraging-associated dilution of mercury concentrations as seals gained mass. Blood mercury concentrations increased by 103% and 24% across the breeding and moulting fasts, respectively, demonstrating a fasting-associated concentration of mercury as seals lost mass. In contrast to blood, mercury concentrations in female's muscle increased by 19% during the post-breeding foraging trip and did not change during the post-moulting foraging trip. While fasting, female muscle mercury concentrations increased 26% during breeding, but decreased 14% during moulting. Consequently, regardless of exposure, an animal's contaminant concentration can be markedly influenced by their annual life-history events. Mercury concentrations in foraging and fasting seals These are the supporting data for Peterson et al. 2018 "Foraging and fasting can influence contaminant concentrations in animals: an example with mercury contamination in a free-ranging marine mammal." Included is the ID of each individual seal, the sex of each seal, and the date of the sample collection. We indicate which samples we used in each paired analysis (blood, muscle, and hair analyses across foraging trips or fasting periods). We indicate the Foraging Trip (Post-breeding vs. Post-molting) or Fasting Period (Breeding vs. Molting) that was used in ...