Distribution, abundance, and habitat associations of young of the year of rockfish species (Sebastes spp.) in deep waters along the central coast of California

Abstract

— The distribution and abundance of demersal young of the year (YOY) of rockfish species ( Sebastes spp.) were investigated over a 17-year period along the central coast of California at depths of 19–326 m. More than 87,000 YOY rockfish were counted during surveys of 1292 transects on the seafloor. The 3 most abundant species were the pygmy ( S. wilsoni ), halfbanded ( S. semi-cinctus ), and shortbelly ( S. jordani ) rockfish. Young of the year of many rockfishes were found at greater depths than have been previously reported. The highest densities of all species combined occurred in shallow and intermediate depths ( ≤ 100 m). Most YOY rockfish occupied rock or mixed substrata, except the greenstriped ( S. elongatus ) and stripetail ( S. saxicola ) rockfish, which were associated primarily with soft sub-strata. Statistically significant ( P <0.01) hot spots of YOY rockfish densities were located throughout the region, but only Soquel Canyon, a known refuge for large adult rockfish (>50 cm in total length), was a significant ( P <0.01) cold spot. Biological processes (e.g., ontogenetic movement and predation) and environmental characteristics (e.g., seafloor habitat and oceanographic conditions) are potential influences on the distribution of YOY of rockfishes. The results of our study provide insights into the distributions of YOY of rockfishes in deep, complex sea-floor habitats and can help improve estimation of year-class strength through targeted surveys of preferred habitats.