(Figure 1) Sea urchin and anemone abundance from sites at North Vulvano Island@en

R1-R3 = reference sites away from the CO2 vents, and hence representative of 'present day' pCO2 conditions. S1-S3 = sites with increasing proximity to the vents thus provided a gradient of decreasing pH/increasing pCO2.R1-R3为远离二氧化碳喷口（CO2 vents）的参照位点，因此可代表"现今"的二氧化碳分压（pCO2）环境条件。S1-S3为与喷口距离愈发邻近的位点，由此形成了pH逐步降低、二氧化碳分压逐步升高的环境梯度。