Metals and other trace elements in plasma and feathers of seabirds breeding in Svalbard.

We assessed the concentrations of metals and other trace elements in two of the most common seabird species breeding on Svalbard, the black-legged kittiwake (Rissa tridactyla) and the Brünnich's guillemot (Uria lomvia). Both of these species feed mostly on fish and crustaceans but have different foraging strategies, kittiwakes being surface feeders while guillemots are divers. We investigated the concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), selenium (Se) and zinc (Zn) in the plasma and body feathers of black-legged kittiwakes (n = 17), as well as in the body feathers of Brünnich's guillemots (n = 13). Samples were collected from adult birds at two time points, one week apart during July 2017 in Kongsfjorden, Svalbard. Of the non-essential trace elements, As was found at the highest median concentration at both the first (56.23 ng/g ww) and second (39.99 ng/g ww) sampling timepoints in the kittiwake plasma. When separating for the sexes, as well as sampling time, males sampled at the first sampling time point had significantly higher concentrations of As (median at 0.087 ng/g versus 0.039 ng/g) and Se (median 0.26 ng/g versus 0.16 ng/g) compared to males sampled at the second time point. There was no significant difference in plasma concentrations between females at first and second sampling time points. Kittiwake feathers contained significantly higher concentrations of As, Cd and Hg than guillemot feathers, while guillemot feathers had significantly higher concentrations of Cu, Pb and Zn. However, of the non-essential elements in both kittiwake and guillemot feathers Hg was found with the highest median concentrations at 5160 and 1080 ng/g, respectively, thus in kittiwakes exceeding the level of 5000 ng/g associated with adverse effect (e.g., impaired reproduction). Levels of Hg and Se found in the kittiwake feathers were higher than previous studies on seabirds in the Arctic.