A comparison of the life history and distribution of vermilion rockfish (Sebastes miniatus) and its cryptic pair, sunset rockfish (S. crocotulus) along the Pacific Coast

Abstract

The presence of cryptic species within exploited fisheries presents challenges for researchers and managers who must balance occasionally divergent commercial and conservation goals. These challenges may be exacerbated when the component taxa have different life histories and historical catches. We used advanced genomics techniques to separate an economically and ecologically important cryptic species pair, vermilion rockfish and sunset rockfish (Genus: Sebastes), into its constituent species. Over 30,000 tissue specimens were analyzed to clarify species-specific life history traits and improve the information available for research and management. Vermilion rockfish were observed from Canada to Mexico, generally in waters shallower than 130 m, while sunset rockfish were encountered from Point Arena, California to Mexico and were common in both shallow waters and offshore banks to at least 300 m. Sunset rockfish grew faster and reached larger maximum sizes, but vermilion rockfish exhibited older maximum ages. As a result of spatial and depth-based management which disproportionately protected deeper waters, vermilion rockfish have likely been subjected to greater commercial and recreational fishing pressure than sunset rockfish throughout most of the 21st century. Improved understanding of the unique life and catch histories of the two species may have implications for how this and other cryptic species pairs are assessed and managed in the future.