We studied the responses of larvae of Macoma balthica to a range of future CO2
scenarios using large mesocosms encompassing the entire pelagic community. We focused on the growth and settlement process of M. balthica when exposed to future CO2
levels, and found the size and time to settlement to increase along the CO2
gradient, suggesting a developmental delay. The strong impact of increasing CO2
on early-stage bivalves is alarming as these stages are crucial for sustaining viable populations.