Present in most coastal waters for millions of years, the scallop now embarks on a true odyssey—the journey of scientific research. Capable of preserving and providing ultra-precise information about environmental changes over millennia, it serves as an unexpected indicator of the state and evolution of the ocean. Alongside a multidisciplinary team, Laurent Chauvaud, a researcher at CNRS, takes us from the harbor of Brest to the poles, where the scallop becomes a key ambassador for the ecological cause...