Mixed-stock analysis of wintertime aggregations of striped bass along the Mid-Atlantic coast

Abstract

Summary Most larger individuals of migratory striped bass Morone saxatilis from the two major Atlantic coast stocks, the Chesapeake Bay and Hudson River, appear to winter in mid-Atlantic coastal waters. But it is not known whether they exhibit differential wintertime distributions in accordance with the latitudinal differences in locations of these two estuaries. Mixed-stock analyses were conducted based on mitochondrial DNA and nuclear DNA genotypic frequencies on wintertime collections of striped bass from coastal waters. No significant differences (P > 0.05) were seen in the proportions of striped bass from the two stocks between collections made from the Delaware Bay mouth and Cape Hatteras in 1997. However, there was a substantially higher Hudson contribution to a 1995 collection from coastal New Jersey (0.349, SD = 0.136) than to the combined 1997 Delaware Bay mouth and Cape Hatteras collection (0.157, SD = 0.072), suggesting this question deserves further study. Additionally, use of the original four reference samples from Chesapeake Bay tributaries (Choptank, Potomac, Rappahannock, Upper Bay) proved adequate alone in characterizing the Chesapeake Bay stock in simulations in which additional tributary collections (Nanticoke, Patuxent, Pocomoke) were added.