Gizzard shad were discovered in Roosevelt Lake during a recent fish survey of the lake. Gizzard shad, which are also called hickory shad, herring and skipjack, are native to eastern North America, especially in the Mississippi River drainage. They typically grow to 9 to 14 inches in length, but some have been reported to exceed 20 inches. The concern is that these shad will compete with threadfin shad, which are currently eaten by the larger fish in the lake. The threadfin shad population would then decrease, and the gizzard shad would probably grow too large for bass and crappie to eat. This would cause fishing conditions at the lake to suffer. Stay tuned for updates on this.