The effect of sediment mixing on mercury dynamics in two intertidal mudflats at Great Bay Estuary, New Hampshire, USA.

ABSTRACT: Estuarine sediments store particulate contaminants including mercury (Hg). We studied Hg sediment dynamics in two intertidal mudflats at Great Bay estuary, NH, over multiple years. Sediments at both mudflats were physically mixed down to ~10 cm, as determined by ⁷Be measurements, albeit via different mechanisms. Portsmouth mudflat (PT) sediments were subject to bioturbation by infaunal organisms and Squamscott mudflat (SQ) sediments were subject to erosion and redeposition. The presence of higher concentrations of fresh Fe(III) hydroxide at PT suggested bioirrigation by the polychaetes (Nereis virens). At depths where infaunal bioirrigation was observed, pore-water inorganic Hg (Hg_i) and methylmercury (MeHg) were lower potentially due to their interaction with

SUBMITTER: Brown LE 

PROVIDER: S-EPMC4765959 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature