Marcela Cornejo was born in Santiago, Chile. She is Oceanographer from the Pontificia Universidad Católica de Valparaíso with a Doctorate in Oceanography from the University of Concepción, Chile. Marcela is a full professor at the Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Chile, and director of the Laboratory of Marine Biogeochemistry of Greenhouse Gases (LABGEI). She also is part of the Instituto Milenio de Oceanografìa.

Her research focuses on the carbon and nitrogen cycle in aquatic environments and the air-sea greenhouse gas fluxes. During her career, she has carried out studies in the upwelling zone and oxygen minimum zone of the eastern South Pacific, seamounts, South Pacific gyre, fjords in the Chilean Patagonia and Antarctica.