Genomically-informed Fisheries Management of White Seabass (Atractoscion nobilis)

The white seabass (Atractoscion nobilis) is among the most valuable species targeted by commercial and recreational fisheries in California and Baja California, Mexico. Paramount to the effective management and conservation of... [ view full abstract ]

The white seabass (Atractoscion nobilis) is among the most valuable species targeted by commercial and recreational fisheries in California and Baja California, Mexico. Paramount to the effective management and conservation of this bi-national stock is knowledge of white seabass life history and ecology, and of the size and spacing of white seabass populations maintained by genetic connectivity. Here we present a genome-level survey of white seabass across much of their Pacific coast distribution to better understand the population structure of this species in the wild. Our method can be adapted for any non-model species and is a relatively affordable and scalable approach for resource managers to conduct an initial genome-scale, rangewide survey of a species of interest. We characterized eight unique sample locations plus multiple replicates using a pooled RAD-seq technique that produced a final dataset of 1561 SNPs on 261 contigs of 300-600bp length (mean = 420bp), distributed across the genome. Each SNP had at least 40x coverage and was scored across all pools. We found no indication of genetic structure across putatively neutral genomic regions, and few outlier loci across populations. These results are supported by preliminary electronic tagging data showing frequent long-distance movements of adult white seabass along the Pacific Coast, but contrast with previous genetic studies and otolith microchemistry data that indicate a distinct sub-population south of Punta Eugenia in Baja. We discuss the implications of these data for the management and conservation of wild populations across the United States–Mexico border.