Stable Carbon Isotopes of Phytoplankton as a Tool to Monitor Anthropogenic CO2 Submarine Leakages

Water

Mirta Smodlaka Tankovic¹  Ana Baricevic¹  Bor Krajnc²  Nives Ogrinc²  Federica Cerino³  Michele Giani³  Paola Del Negro³  Cinzia De Vittor³  Lidia Urbini³  Federica Relitti³ 

[1] Center for Marine Research, Ruder Boskovic Institute, 52210 Rovinj, Croatia;Department of Environmental Sciences, Jožef Stefan Institute, 1000 Ljubljana, Slovenia;National Institute of Oceanography and Applied Geophysics—OGS, 34010 Sgonico (TS), Italy;

关键词: diatoms;    CO₂ leakage;    ¹³C;    carbon fixation;    Carbon Capture and Storage;    Phytoplankton;   

DOI  :  10.3390/w12123573

来源: DOAJ

【 摘 要 】

This study aims to validate the stable carbon isotopic composition (δ¹³C) of phytoplankton as a tool for detecting submarine leakages of anthropogenic CO_2(g), since it is characterised by δ¹³C values significantly lower than the natural CO₂ dissolved in oceans. Three culture experiments were carried out to investigate the changes in δ¹³C of the diatom Thalassiosira rotula during growth in an artificially modified medium (ASW). Three different dissolved inorganic carbon (DIC) concentrations were tested to verify if carbon availability affects phytoplankton δ¹³C. Simultaneously, at each experiment, T. rotula was cultured under natural DIC isotopic composition (δ¹³C_DIC) and carbonate system conditions. The available DIC pool for diatoms grown in ASW was characterised by δ¹³C_DIC values (−44.2 ± 0.9‰) significantly lower than the typical marine range. Through photosynthetic DIC uptake, microalgae δ¹³C rapidly changed, reaching significantly low values (until −43.4‰). Moreover, the different DIC concentrations did not affect the diatom δ¹³C, exhibiting the same trend in δ¹³C values in the three ASW experiments. The experiments prove that phytoplankton isotopic composition quickly responds to changes in the δ¹³C of the medium, making this approach a promising and low-impact tool for detecting CO_2(g) submarine leakages from CO_2(g) deposits.

【 授权许可】

Unknown