Microsatellite analysis reveals strong genetic connectivity in Scomber colias along the Northwest coast of Africa

Understanding the population structure of wild marine species is essential for sustainable management, particularly in environments with high gene flow where it can be difficult to identify genetic differentiation. Climate change adds further complexity to population dynamics by altering habitats, necessitating a clear definition of stock boundaries and accurate identification of harvested species. This study uses nine microsatellites to examine the population structure and connectivity of Scomber colias along the northwest African coast from Larache (Morocco, 34°N) to Senegal (13°N). The genotyping of 266 individuals across nine sampling areas revealed significant genetic diversity (PIC = 0.86, H_E = 0.859, H_O = 0.805), but a deficiency in heterozygosity indicates non-random mating and suggests Wahlund effects. Despite the high polymorphism of the nine neutral markers, we observed significant deviation from panmixia (F_ST = 0.0047, P-val < 0.0001), subtle yet biologically significant genetic structuring. These findings provide valuable insights and baseline information that can enhance the design of management strategies to maintain genetic connectivity and consider potential subpopulation structures. This study emphasizes the need to integrate genetic insights into the management of S. colias stocks in the Northwest Atlantic to promote sustainable harvesting and ensure the resilience of marine resources.