Nutrient concentrations in 59 Antarctic fur seal (Arctocephalus gazella) scats collected in 2022 in two colonies of the Kerguelen Islands, southern Indian Ocean

Total concentrations of major constitutive chemical elements in biological tissues (P, Ca, K, Na, Mg) were determined by inductively coupled plasma atomic emission spectrometry (ICP-OES, Vista-Pro Varian). Aliquots of samples (∼250 mg dry mass of homogenised powder) were digested using a 6:2 (v/v) mixture with nitric acid (HNO3 69%, Trace Metal Grade®, FisherScientific) and hydrochloric acid (HCl, 34%, Trace Metal Grade®, FisherScientific).

Acidic digestion of the samples was performed over-night at room temperature and then in a microwave oven (START-D, Milestone). Finally, the digestats were diluted to 50 mL with ultrapure water before analyses with ICP-OES. Total concentrations of essential trace nutrients (As, Co, Cu, Fe, Mn, Ni, Se, Zn) were determined by inductively coupled plasma mass spectrometry (ICP-MS, ICAP-Qc ThermoFisher).

Aliquots of samples (∼200 mg dry mass of homogenised powder) were placed in Teflon bombs and mineralized with a mixture of ultrapure HNO3 acid (PlasmaPure Plus grade, SCP Science®) and ultrapure water using a micro-wave (ETHOS-UP, Milestone). The digests were then diluted to 50 mL with ultrapure water before analyses with ICP-MS. The quality assurance of all metal analyses relied on blank and internal standard controls, and on the accuracy and reproducibility of data relative to the certified reference materials (CRMs) used in each analytical run.

Blank values were systematically below the detection limits and CRM values concurred with certified concentrations. Results for the CRMs are provided in the dataset