Based on the glacial to postglacial δ¹³C differences between endobenthic Uvigerina peregrina species from the Alboran basin and from other mediterranean basins, changes in the fertility of the western part of this basin during the last deglaciation are reconstructed. As a result of particulate organic carbon (POC) rain from the highly productive upwelling cell along the northwestern margin of the Alboran basin, U. peregrina is presently depleted by about 1.6‰ with respect to the measured δ¹³C values of bottom water ΣCO₂ and by about 0.9‰ with respect to specimens from other areas of the western Mediterranean or from the Gulf of Cadiz within the Mediterranean Outflow Water. The Uvigerina δ¹³C difference between the Alboran Sea and the Gulf of Cadiz (Δδ¹³C), was close to 0‰ at the beginning of the last deglaciation and during the late glacial time. This suggests that highly fertile systems set in the Alboran Sea near 16 kyr B.P. Two rapid increases in the Δδ¹³C offset are recorded near 15 kyr and 11 kyr B.P. Fluctuations around 1.1 to 1.2‰ occurred during the early Holocene, and a maximum was reached near 9 kyr B.P. After 4 kyr the Δ δ¹³C offset decreased to its present-day average value of 0.9‰. Changes in the intensity of surficial production cannot account for all the observed fluctuations, especially in the early Holocene time. A strong decrease in the intermediate and deep water ventilation of the Alboran basin may have occurred near 8–9 kyr, in phase with the last stagnant phase in the eastern Mediterranean and the deposition of Sapropel S1. As a result, the redistribution and remineralization at depth of the produced organic matter was incomplete. The POC rain reaching the sediment was locally intensified and caused the lowering of the δ¹³C values of endobenthic foraminifers such as U. peregrina. The benthic ¹³C signal suggests that the difference between the Alboran Sea and the Gulf of Cadiz was at its maximum. At the same time, an important modification in the water masses structure may have occurred near 9–8 kyr B.P. The deepening of the permanent pycnocline probably related to a thicker Atlantic jet at a stage of high sea level stand is recorded by the replacement of the right coiling N. pachyderma dominance (coincident with a shallow pycnocline) by the G. inflata dominance (coincident with a deep pycnocline). Diatom abundances were strongly reduced indicating an important modification of the productive system. The glacial-postglacial evolution of productivity within the Alboran basin was therefore more complex than in the adjacent Atlantic Ocean and opposite to the global one which displays a general increase in productivity during glacial time. Although it is the global budget of paleoproductivity that would drive the partitioning of carbon within the ocean, local or regional discrepancies with the global glacial-interglacial model must be addressed. Local winds and regional atmospheric pressure systems, which are the forcing factors for circulation and exchange with the Atlantic, control the fertile systems of the Alboran basin.