Objectives

The proposed project has the following objectives:

-        to improve the understanding of the complex physical, chemical and biogeochemical processes of atmospheric Hg fractions/species that govern deposition of oxidized fractions of mercury and re-emission of volatile Hg species in Idrija and the Gulf of Trieste: relevant transformation processes include redox reactions, photochemical, adsorption/desorption, methylation/demethylation and biologically mediated processes;

-        to improve the understanding of mercury dynamics in coastal marine environments of the Gulf of Trieste: assessment of the origins and transformations of all Hg species, including, inorganic, dissolved gaseous and methylated Hg species (MMHg and dimethyl-Hg (DMHg)) will be implemented using state of the art tools including novel isotopic techniques;

-        to investigate Hg and MMHg bioaccumulation in lower food webs in coastal/marine environments: sorption and uptake rates by key marine particles (particulate organic matter (POM), microbes, phytoplankton, zooplankton) along the abiotic/biotic continuum will be investigated using state of the art isotopic techniques under controlled laboratory and mesocosm experiments, and by field observations in the coast-to-open oceans transects;

-        to assess the capacity of terrestrial ecosystems to act as a net source or sink of Hg: mobility and reactivity of terrestrial Hg, its inter-compartmental exchanges and interactions with organic matter will be investigated using tailored experiments at land-sea transects and canopy;

-        to improve comparability of measurements in the atmosphere and other environmental compartments and to validate in-situ biosensors for the determination of bioavailable fraction of mercury in aquatic environment and to test new and validated methodologies in the atmosphere and water in field campaigns;

-        to model the Hg cycle from emissions/releases to bio-accumulation in marine lower trophic levels: existing numerical atmosphere, ocean, and ecosystem models will be coupled and adapted to model Hg cycling in the riverine and coastal region.

-        to support the implementation of the Minamata Convention using improved regional modelling tools: model studies will be performed to examine the impact of natural and anthropogenic drivers on mercury cycling and accumulation. This will support an effectiveness evaluation of mitigation strategies on how land and water management as well as global change scenarios affect MMHg formation and bioaccumulation particularly in marine ecosystems of wider Idrija and Gulf of Trieste region.

-        to disseminate and communicate the results to the relevant stakeholders nationally and internationally and to make further steps in using the results in the planning of water and land management practices in Idrija and wider.

Figure. Mercury cycling in the Idrija region; work implemented so far (right) and the identification of the methodological improvements based on isotopic tools proposed in the proposal (light blue arrows on the left) The study area of the Idrija Mercury Mine, where about 38.000 tons of mercury have been lost to the environment during the past five centuries of mining and ore processing activities, consists of the terrestrial ecosystems throughout the Idrija and Soča river catchments, freshwater ecosystems of the Idrijca and Soča Rivers and the coastal environment of the Gulf of Trieste.