Mercury dynamics in the mangrove-influenced estuary of the Parnaíba Delta, Brazil.

The Parnaíba River Delta (PRD), located in northeastern Brazil, is an ecologically crucial estuarine system little impacted by anthropogenic activities. This study aimed to assess mercury (Hg) contamination levels in the water and sediments and their link to changes in the hydrographic parameters across the delta to evaluate spatial distribution patterns and Hg speciation. Water and surface sediment samples were collected from 12 stations throughout the PRD.