Table 3 Summary of CO₂ impact on benthic organisms and processes at the Basiluzzo Islet sites (soft sediments) and comparison with available benthic data from other shallow natural CO₂ vents (soft and rocky seafloor) at Ischia, Vulcano, and Papua New Guinea.

Significant deviations from the REF are described by upward (enhancing) or downward (declining) arrows, respectively, or by + for changes in community structure. 0, neutral; PNG, Papua New Guinea; OC, organic carbon; EEA, extracellular enzymatic activity; Undist., undisturbed sediments at CO₂ vents; Transpl., medium-term (1 year) transplanted sediments from reference to CO₂-impacted site (REF/CO2-R). For references and detailed description of CO₂ affects on marine environments at natural CO₂ vents, see table S9.