[H-SC07] CCUS (Carbon Dioxide Capture, Utilization, and Storage) for Climate Mitigation

[HSC07-P11] Characteristics of lethal and sub-lethal impacts of CO₂ from marine biological impacts database

*Yuji Watanabe¹, Jiro Suekuni¹, Keisuke Uchimoto¹, Ziqiu Xue¹ (1.Research Institute of Innovative Technology for the Earth)

Keywords:Sub-seabed CO2 geological storage, Biological impact, pCO2

In sub-seafloor CO₂ geological storage, the potential environmental impact assessment of assumed CO₂ leakage must be implemented. To conduct this assessment, information is needed to estimate the impact of increased CO₂ on marine organisms. Around Japan, warm currents such as the Kuroshio Current and cold currents such as the Oyashio Current flow. These currents contribute to regional differences in the characteristics of seawater such as water temperatures, salinity, and total alkalinity. As a result, the partial pressure of carbon dioxide (pCO₂), which is a factor affecting organisms, differs depending on the region. In addition, because the biological composition of the habitat differs between warm and cold currents, it is necessary to organize the information on biological effects according to the CO₂ storage site. Therefore, we have collected various impact data from the literature on CO₂ impacts on organisms from cold to tropical regions and compiled a marine biological impacts database. Lethality data are expressed as the relationship between pCO₂ and the exposure time. For the sublethal data, we categorized the data into major categories such as growth, metabolism, respiration, calcification, metamorphosis, malformation, proliferation, and generation. And relative indices (LnRR, Hedges' d) were calculated to make comparisons among different factors. So far, we have collected 150 records for lethal data and more than 1900 records for sublethal data. In this presentation, we summarize the data collected so far and report the characteristics of lethality and sub-lethality. On the other hand, compiling this information is also useful from the perspective of social acceptance. The general public is often unfamiliar with CCS projects. The fact that an environmental impact assessment is being conducted may leads the public to believe that a risk exists for the project. Furthermore, because the public is unfamiliar with the idea of risk assessment, the public will tend to have concerns about the safety of CCS, even though the probability of risk of leakage is very small. Providing information on the biological effects of CO₂ will help the general public better understand the importance of global warming countermeasures and help them make appropriate judgments about the content of potential environmental impact assessments.