A shad is a type of fish that spends most of its life in the ocean but swims up rivers to lay its eggs, just like salmon do. Shad look somewhat like large herring, with silvery scales and compressed bodies that help them swim swiftly upstream against strong currents.

For centuries, shad were so plentiful in American rivers each spring that colonists called their arrival “shad runs.” People would line riverbanks with nets, catching thousands of fish as they migrated upstream. George Washington loved shad so much that he fished for them at Mount Vernon, and the fish became an important food source during the Revolutionary War. Native Americans had been catching and eating shad for thousands of years before European settlers arrived.

Today, shad populations have declined in many rivers because dams block their migration routes, though conservation efforts are helping them return to some waterways. American shad and hickory shad are common species along the Atlantic coast.