2014 Assessment of the Northern and Southern Rock Sole Stocks in the Gulf of Alaska
Rock sole are demersal fish and can be found in shelf waters to 600 m (Allen and Smith, 1988). Two species of rock sole are known to occur in the north Pacific Ocean, northern rock sole (Lepidopsetta polyxystra) and southern rock sole (L. bilineata) (Orr and Matarese, 2000). Adults of the northern rock sole are found from Puget Sound through the Bering Sea and Aleutian Islands to the Kuril Islands, while the southern rock sole is known from the southeast Bering Sea to Baja California (Stark and Somerton, 2002). These species have an overlapping distribution in the Gulf of Alaska (Wilderbuer and Nichol, 2009). Rock sole are most abundant in the Kodiak and Shumagin areas. The northern rock sole spawns in midwinter and spring, and the southern rock sole spawns in summer (Stark and Somerton, 2002). Northern rock sole spawning occurred in areas where bottom temperatures averaged 3°C in January, and
Southern rock sole spawning began in areas where bottom temperatures averaged 6°C in June (Stark and Somerton, 2002). Rock soles grow to approximately 60 cm and can live in excess of 20 years.
Both rock sole species are managed as part of the shallow-water flatfish complex, which also includes yellowfin sole (Pleuronectes asper), starry flounder (Platichthys stellatus), butter sole (Pleuronectes isolepis), English sole (Pleuronectes vetulus), Alaska plaice (Pleuronectes quadrituberculatus), and sand sole (Psettichthys melanostictus), as these species are caught in the shallow-water flatfish fishery (Turnock et al., 2009).