HR: 0800h
AN: OS51C-1321    [Abstracts]
TI: Mercury speciation in the Mediterranean Sea
AU: * Horvat, M
EM: milena.horvat@ijs.si
AF: Jozef Stefan Institute, Jamova 39, Ljubljana, 1000 Slovenia
AU: Kotnik, J
EM: joze.kotnik@ijs.si
AF: Jozef Stefan Institute, Jamova 39, Ljubljana, 1000 Slovenia
AU: Ogrinc, N
EM: nives.ogrinc@ijs.si
AF: Jozef Stefan Institute, Jamova 39, Ljubljana, 1000 Slovenia
AU: Fajon, V
EM: vesna.fajon@ijs.si
AF: Jozef Stefan Institute, Jamova 39, Ljubljana, 1000 Slovenia
AU: Logar, M
EM: martina.logar@ijs.si
AF: Jozef Stefan Institute, Jamova 39, Ljubljana, 1000 Slovenia
AU: Gibi­­ar, D
EM: darija.gibicar@ijs.si
AF: Jozef Stefan Institute, Jamova 39, Ljubljana, 1000 Slovenia
AU: Vaupotic, J
EM: janja.vaupotic@ijs.si
AF: Jozef Stefan Institute, Jamova 39, Ljubljana, 1000 Slovenia
AU: Pirrone, N
EM: n.pirrone@cs.iia.cnr.it
AF: CNR - Institute for Atmospheric Pollution, University of Calabria, Rende, 87036 Italy
AB: An interesting feature of mercury biogeochemistry in the Mediterranean is that several fish species from the Mediterranean show higher concentrations of Hg in their tissues than same fish species in the Atlantic ocean. although the concentrations of mercury in the open waters of both oceans are similar. It has been suggested that the higher mercury levels noted in many larger pelagic fish species in the Mediterranean are not related to anthropogenic inputs, but rather are due to the higher than average natural environmental levels of this metal originating from the Mediterranean mercury anomaly. Although elevated Hg levels have been noted in environmental matrices from the Mediterranean regions adjacent to known mercury anomalies, the data do not clearly indicate that the effects of these anomalies have been transmitted to open waters or to lower trophic level species living in these waters. In the present contribution data obtained during three oceanographic cruises carried out in the framework of the MERCYMS project (An integrate approach to assess mercury cycling in the Mediterranean basin) funded by EU in the period between 2000 and 2003 will be presented. Measurements included total mercury measurements and its speciation (reactive Hg, total Hg and monomethylmercury (MMHg) in filtered and non-filtered sea water samples, dissolved gaseous mercury (DGM) and dimethylmercury (DMHg) in open and coastal waters of the Mediterranean Sea. Radon, as a tracer gas of tectonic activity was also measured in depth profiles. The results presented clearly show that hg species distribution in surface and deep oceanic waters is affected by several dynamic processes such as photochemical transformation at the surface, phytoplankton biomass stratification in the photic zone, development of an oxygen depletion zone at intermediate depths and diffusion from deeper layers due to biological and/or tectonic activities.
DE: 4807 Chemical speciation and complexation
DE: 4875 Trace elements
DE: 4251 Marine pollution
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting