Title: Biomass and geographical distribution of seven small pelagic fish species in relation to temperature conditions in Mauritanian waters.

The focus for this study was to research small pelagic fish resources within the Mauritanian EEZ, to calculate stock biomass and investigate whether species distribution is related to temperature conditions. Acoustic backscatter data from the RV Dr Fridjof Nansen were post-processed using the software Large-Scale Survey System (LSSS) Version 2.0. Species allocation based on the species proportion in catch and biomass estimates were calculated following FAO guidelines. The study results show that temperature influences species’ geographical distribution. Chub mackerel, Atlantic horse mackerel, and sardines are more prevalent in the colder waters of the northern part of the EEZ, while round sardinella, flat sardinella and Cunen horse mackerel are more prevalent in the warm waters of the central and southern part of the EEZ. Though anchovy and Cunen horse mackerel were found in both colder and warmer waters from the north to the southern area. The biggest biomass estimate was the anchovy followed by Cunen horse mackerel and flat sardinella, generally, these species were found in shallower areas.