STRIPED BASS POPULATION SUBDIVISION WITHIN THE SANTEE-COOPER SYSTEM, SOUTH-CAROLINA

Population subdivision was indicated in striped bass (Morone saxatilis ) from the Santee-Cooper system, South Carolina. Samples from the two major spawning grounds, the Congaree River (n = 273) and Wateree River (n = 111), and from the Santee River, the source of hatchery broodsto ck (n = 128), were collected during the 1992, 1993, and 1994 spawning seasons. Polymerase chain reaction and restriction fragment length pol ymorphism (PCR-RFLP) assays of three independently segregating loci we re used to screen population samples from the system. An allele freque ncy difference among samples from the three rivers was detected at the SB83 locus. In addition, the SB14 locus showed a significant temporal change in allele frequencies in the Santee River sample. Furthermore, a heterozygote deficiency was observed in the Santee and Congaree Riv er samples, suggesting either inbreeding due to hatchery augmentation or admixture of two distinct populations, These data suggest that ther e is population substructure in the Santee-Cooper system and that futu re hatchery augmentation efforts should recognize this population subd ivision.