J1-8156 - Stable isotopes in the study of the impact of increasing CO2 levels on C and Hg cycling in coastal waters

Stable isotopes in the study of the impact of increasing CO2 levels on C and Hg cycling in coastal waters, 1.5.2017―30.4.2020, Nives Ogrinc

The proposed project deals with the use of stable isotopes to better understand the origin and processes of C and Hg in relation to increasing levels of atmospheric CO2 in the coastal marine ecosystem. Combined molecular and multi-isotopic signatures of C and Hg are a rapidly emerging area of research, opening up new ways of studying their sources and fate in the environment. A study of the inorganic and organic carbon flux will provide high-quality data in the Gulf of Trieste (northern Adriatic Sea), an example of an anthropogenically impacted coastal area, which will be further integrated into the currently developed Global Ocean Acidification Observing Network (GOA-ON). The results will yield a comprehensive dataset on the carbonate system and organic carbon pool, which will help to identify the processes enhancing marine acidification and its impacts on the coastal marine system. In this context, the project sets out to develop an optical sensor (optode) for measuring in situ the partial pressure of CO2 gas (pCO2). A second experiment (mesocosmos) will also decode how different sources (natural, anthropogenic) of CO2 influence biological systems (phytoplankton) using stable carbon isotopes. Once developed, these methods will find application in other field of research, for example, for detecting CO2 leakage from proposed subsea carbon capture and storage (CCS) sites. In the case of Hg, research will include two techniques representing “state-of-the-art” in the environmental studies, i.e. Hg isotopic composition analyses using multicollector-Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) and compound specific isotope analysis (CSIA) of C in MeHg. This will provide a better understanding of the complex mechanisms that regulate toxic forms of Hg in the environment and their transfer within the food chain as well as representing an innovative and original contribution to the science. The project results will be important for the management and mitigation of the greenhouse effect in coastal marine areas in the future.


The project combines the complementary expertise of two research institutions and SME in Slovenia and four well experience international partners from Italy (OGS, University of Trieste), France (GET, Toulouse) and Canada (Trent University). Moreover, the effective collaboration with ongoing EU project consortia will provide a forum for further exploitation of the results.



J1 8156 structure3

Project team 

Jožef Stefan Institute

Nives Ogrinc

Milena Horvat

David Kocman

Marko Štrok

Ingrid Falnoga

Doris Potočnik

Katarina Vogel Mikuš 

National Institute of Biology - Marine Biological Station

Jadran Faganeli

Nives Kovač

Vladimir Malačič

Katja Klun


IOS, Institute for Environmental Protection and Sensors

Aleksandra Lobnik

Andreja Gutmaher

Aljoša Košak

Matejka Turel

Polonca Nedeljko


Financial sources






Related projects


TC INT7019: Supporting a Global Ocean Acidification Observing Network towards Increased Involvement of Developing States