High mercury accumulation in deep-ocean hadal sediments.

ABSTRACT: Ocean sediments are the largest sink for mercury (Hg) sequestration and hence an important part of the global Hg cycle¹. Yet accepted global average Hg flux data for deep-ocean sediments (> 200 m depth) are not based on measurements on sediments but are inferred from sinking particulates². Mercury fluxes have never been reported from the deepest zone, the hadal (> 6 km depth). Here we report the first measurements of Hg fluxes from two hadal trenches (Atacama and Kermadec) and adjacent abyssal areas (2-6 km). Mercury concentrations of up to 400 ng g^-1 were the highest recorded in marine sediments remote from anthropogenic or hydrothermal sources. The two trench systems differed significantly in Hg concentrations and fluxes, but hadal and abyssal areas withi

SUBMITTER: Sanei H 

PROVIDER: S-EPMC8155115 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature