Decadal differences in polycyclic aromatic compound (PAC) concentrations in two seabird species in Arctic Canada

Seabirds are exposed to a variety of environmental contaminants in the Arctic. While the persistence, bioaccumulation, and toxicity of some groups of contaminants have been well-studied in seabirds since the 1970s, there is less known about polycyclic aromatic compounds (PACs). With increased vessel traffic, and potential oil and gas development in the Arctic region, there is a need to understand existing PAC exposure in biota against which to compare potential effects of anticipated increases of PACs in the marine region. Thick-billed murres (Uria lomvia) and northern fulmars (Fulmarus glacialis) collected in the Baffin Bay - Davis Strait region during the International Polar Year (IPY; 2007-08), and during a recent Strategic Environmental Assessment (2018; SEA) were examined for hepatic PAC concentrations. We found that fulmars generally had higher concentrations of PACs than the murres, but murres and fulmars sampled in 2007/08 had higher concentrations of most groups of PACs compared to birds from 2018. The one exception to this pattern was that the sum of the alkylated congeners of the heterocyclic aromatic compounds containing a sulfur atom (dibenzothiophene; SAHET) was significantly higher in murres in the more recent sampling period (2018) as compared to 2007/08. SAHETs likely reflect recent exposure tomore refined petroleumproducts associated with small boats, such as diesel, gasoline and motor oil. This work highlights the need for longitudinal studies on PAC concentrations in biota for us to gain a better understanding of how Arctic biota are exposed to this group of contaminants, and the potential deleterious effects associated with PACs.

Automated summary

Seabirds in the Arctic are exposed to various environmental contaminants. This study focused on polycyclic aromatic compounds (PACs), which have received less attention compared to other contaminants. The study found that fulmars generally had higher PAC concentrations than murres, and the concentrations of most PAC groups were higher in birds from 2007/08 compared to 2018. The exception was the higher concentrations of alkylated congeners of heterocyclic aromatic compounds in murres from 2018, indicating recent exposure to refined petroleum products.