We utilize 430 base pairs of D-Loop sequence data to characterize mitochondrial polymorphism and estimate the female evolutionary effective population size, Nef, of the Southern California Bight population of white seabass, (Atractoscion nobilis). The D- Loop sequence data is highly polymorphic and reflects a population expansion signal according to both a coalescent-based and moment-based estimation procedures. The coalescent-based approach produces a Nef of 54,260, based on a mutation rate of 7.36 x 10-7 base-pairs/generation. In addition, the positive, exponential growth rate is 1.22.x 10-3 .