Claremont Beach samples the differences between years were not significant.

Comparison between Chesapeake Bay tributaries.--Data for all locations and all years for which collections were available were combined in testing for significant differences in meristic counts between two rivers. There was a significant difference in the meristic counts between the York and James fish in all instances; between the Rappahannock and James, the Rappahannock and York, and the James and Susquehanna in three instances; and between the Rappahannock and Susquehanna, and the York and Susquehanna in two instances (table 9). Where applicable, the interaction between years and rivers was not significant. The differences in meristic counts between rivers indicated that discrete populations of shad occurred in the Chesapeake Bay tributaries.