Preliminary results on trace element levels in three species of seabirds from the western Indian Ocean

As top predators of pelagic food webs, marine birds naturally bioaccumulate essential and non-essential elements. Levels of arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), selenium (Se) and zinc (Zn) were determined in the liver, kidneys and muscles of three species of marine birds found on Reunion Island: Barau's Petrel (Pterodroma baraui), Audubon's Shearwater (Puffinus lherminieri bailloni) and the White-tailed Tropicbird (Phaethon lepturus). The study of the 89 birds sampled put forth variations of the elemental levels between organs, age groups (juveniles versus adults) and species. Adult Barau's Petrels showed the highest values of Hg and Cd. This study offers a first glimpse of the levels of impregnation of eight trace elements in top predators of the western Indian Ocean and brings answers to certain questions related to the processes of bioaccumulation in marine top predators of the tropical Indian Ocean.