Based on genetic (Chow et al., 2007) and parasite (Garcia et al., 2011) studies, three stocks are considered to exist in the Atlantic Ocean and assessed separately by the International Commission for the Conservation of Atlantic Tunas (ICCAT): North Atlantic, South Atlantic and Mediterranean (Kotoulas et al., 1995). Precise stock boundaries are not clear but South and North stocks are separated at 5ºN (ICCAT, 2013a).