“…In Mediterranean waters, a significant decline in biomass occurred with an increased risk of overexploitation, coinciding with a decrease in the size and conditions of the individuals (FAO, 2018). Numerous studies on the European sardine population structure have been carried out using several phenotypic methods, including body morphometrics (Baibai et al ., 2012; Mounir et al ., 2019; Silva, 2003), otolith shape (Jemaa et al ., 2015b; Neves et al ., 2021) and otolith microchemistry (Castro, 2007; Correia et al ., 2014), as well as distinctive genetic methods (Atarhouch et al ., 2006; Baibai et al ., 2012; Chlaida et al ., 2006; González & Zardoya, 2007; Imsiridou et al ., 2019; Kasapidis et al ., 2011; Laurent et al ., 2007; Laurent & Planes, 2007; Ruggeri et al ., 2012). These studies have led to inconclusive results on the identification of stock boundaries, particularly genetic studies that unanimously suggest a weak genetic structure for this species (Baibai et al ., 2012; Kasapidis, 2014).…”