Toxicants, including the heavy metals mercury, cadmium, lead and arsenic can have deleterious impacts on marine mammal health and survival. The vulnerability of pinnipeds to toxicant bioaccumulation means they have a role as sentinels of ecosystem health; establishing baseline toxicant concentrations in upper trophic species, such as the Australian fur seal (Arctocephalus pusillus doriferous), is essential for monitoring anthropogenic impacts in the marine ecosystem.
In this study, trace element and heavy metal concentrations will be determined in pup fur and blood serving as an indirect measure/proxy of maternal trace element and heavy metal concentrations. As the first hair coat (lanugo) grows in-utero, pup fur concentrations mirror maternal blood concentrations of these toxicants during gestation. Similarly, toxicant concentrations in pup blood are a secondary indicator of maternal concentrations in the milk.
During the 2013/14 census, blood (n=100) and fur (n=229) samples were collected from Australian fur seal pups at several breeding colonies in Victoria and Tasmania. These colonies (Lady Julia Percy Island, Seal Rocks, The Skerries, Tenth Island and Judgement Rocks) reflect varying degrees of intensity of coastal industrial enterprises across the species’ range. Analysis of blood samples collected from four of these colonies in 2007-2008 (n=50 from each colony) also provides archive samples for temporal comparisons of toxicant concentrations with the 2013/14 samples. The concentration of 13 trace elements and heavy metals (Hg, Se, Zn, Fe, Al, Cu, Ni, Co, Cr, Cd, Pb, As, Mg) in fur and blood will be determined by inductively coupled plasma mass spectrometry.
In addition to presenting reference values for trace elements and heavy metals across the geographical range of the Australian fur seal, we report the effect of varying anthropogenic influence on these concentrations. Demonstration of anthropogenic impacts associated with environmental toxicants will inform mitigation strategies, aiding species and marine ecosystem conservation.