Rapid temporal decline of mercury in Greenland halibut (Reinhardtius hippoglossoides)

Mercury (Hg) pollution in the ocean is an issue of global concern, however bioaccumulation regimes this ubiquitous pollutant marine apex predators have important knowledge gaps. Our fish length and stable isotope (δ15N δ13C) normalized data Greenland halibut (GH) (Reinhardtius hippoglossoides) showed that Hg fillet tissue decreased by ~35–50 %, over a ten-year period from 2006 to 2015 (n = 7 individual sampling years). was predominantly methylmercury form (>77 %). Results Bayesian information theoretic model GH concentrations with time its associated declines air emissions, estimated trophic position, potentially lower degree demersal prey use as indicated temporal trend shifts nitrogen (δ15N) carbon (δ13C) values. accounted for about one third observed reduction Hg. study demonstrates importance simultaneously considering food web dynamics drivers marine, deep water species highlights effectiveness regulations on predator overall seafood safety.