<p>Blue carbon ecosystems (BCEs)—coastal and marine habitats that capture and store large amounts of carbon—cover a small ocean area but are critically important for their role in carbon sequestration and storage, and their location, primarily in the coastal zone, often puts them at risk due to their use for human activities. Bivalve aquaculture, which can have both positive and negative effects on ecosystem functioning, is expanding its footprint in these environments, creating increased opportunities for interaction with BCEs. Here, we estimate both the current and future overlap of bivalve aquaculture and BCEs, finding significant areas of interaction, particularly in regions such as Asia that have high densities of bivalve aquaculture. We estimate this area of overlap could encompass over 41,000 bivalve farms, and currently stores approximately 12 million Mg C and sequesters about 147,000 Mg C yr^-1. This presents both risks and opportunities for conservation and highlights the need for further research and strategic coastal management.</p>