This study reconstructs bottom water oxygenation, organic matter fluxes, and Mediterranean Outflow Water (MOW) dynamics in the Gulf of Cadiz during the Early to Middle Pleistocene Transition (EMPT), using high-resolution multiproxy data from the IODP Site U1387, comprising Marine Isotope Stage (MIS) 28 to MIS 19. Along with benthic foraminifera assemblages, we integrate stable isotopes, total organic carbon (TOC), total alkenone concentrations, geochemical and sedimentological proxies (Zr/Al ratio, grain size) to identify environmental controls across glacial–interglacial cycles and millennial-scale events.