Mercury biomagnification in a coastal Louisiana food web following the 2010 Deepwater Horizon oil spill

The estuarine environments surrounding coastal Louisiana create favorable conditions for microbially mediated mercury (Hg) methylation and subsequent bioaccumulation by biota. In 2010, the Deepwater Horizon (DWH) oil spill released large amounts of which, despite having low Hg concentrations, had potential to influence methylmercury (MeHg) bioavailability in zone. To explore this possibility, we assessed concentrations trophodynamics food web prior immediately following DWH compared these metrics with an adjacent ecosystem northern Gulf Mexico. We found no differences MeHg between oysters collected years (1986–2007) those during or months after (May December 2010). When comparing tissue carbon nitrogen stable isotope values across 13 species bivalves, shrimp, crabs, fishes, birds evidence significant biomagnification within driven species’ trophic position their use differing basal sources. addition, also differed two ecosystems, post-spill (2010) pre-spill Alabama (2008–2009). While there was a higher magnification factor relative Alabama, baseline were Alabama. high degree Louisiana, regional variation, underscores need monitor over space time better evaluate short long-term ecological consequences events like spill.