The concentration of carbon dioxide in the atmosphere is rising due to human activities. The ocean has absorbed almost 30 % of the total emissions and stored in deeper waters. We studied the southern Adriatic, an area where dense water forms and sinks, helping move carbon from the surface to depth. Using a recently validated long-term dataset, we found that over the past decade this region acted as a net sink of carbon dioxide, highlighting its role in storing carbon in the Mediterranean Sea.