Species- and Tissue-Specific Accumulation of Polycyclic Aromatic Compounds in Three Arctic Seabirds

Polycyclic aromatic compounds (PACs) are a complex class of toxic organic contaminants whose environmental fate and risk in the Arctic are poorly understood. The accumulation potential and risk to marine wildlife of these compounds was assessed by quantifying 86 PACs in liver and egg tissues of three species of Arctic seabirds; thick-billed murres (Uria lomvia), northern fulmars (Fulmarus glacialis), and black-legged kittiwakes (Rissa tridactyla). Eggs and adult birds were collected from Prince Leopold Island, Nunavut in 2023. Both homocyclic and heterocyclic PACs were detected in livers and eggs, and were significantly higher in liver, across all species. Total mean concentrations of homocyclic and heterocyclic PACs in liver (n = 30) were 2250 and 2720 ng/g, respectively. Conversely, egg tissues (n = 26) accumulated substantially smaller PACs, averaging 97.9 (homocyclics) and 449 ng/g (heterocyclics). Despite nesting sympatrically, considerable differences in PAC profiles were also observed among species and tissue types and likely reflect species-specific differences in PAC exposure, accumulation, and metabolism, although the factors driving these differences remain unclear. This research provides new insights on maternal transfer of PACs and underscores the need to expand monitoring efforts beyond conventional homocyclic compounds to accurately assess the toxicological risk to vulnerable Arctic wildlife.