What's New A Few Fast Facts: About The American Shad (Alosa sapidissima) The American shad begins life in a freshwater river or stream. Shortly after hatching, it heads downstream to the ocean. Along the way, the young shad feeds on insect larvae. They spend several years in the ocean, living on small animals called zooplankton (zoh-oh-PLANK-ton). As marine adults, shad typically travel in schools extensively along the coast, ranging from Labrador to Florida. Shad bound for the Schuylkill (and the fish ladder across from the Interpretive Center) begin their journey in the Delaware Bay. They will wait in the bay until the river water reaches a temperature of at least 43° Fahrenheit (6° Celsius). Fish that migrate from the sea to fresh water are anadromous (a NAD rum us), which means "running upstream." Once on their spawning run, shad eat very little. As a result, the shad that mate weigh about 40 percent less than they did at the mouth of the river. Unlike salmon, all shad don't die after spawning. In this area, about half of those that spawn return to the ocean. Shad begin feeding again after spawning. The first half of the 20th century was hard on local shad. A thirty-mile stretch of the Delaware, from just above Philadelphia to below Chester, was so badly polluted that it all but stopped the shad's spawning migration. But from the late 1950s into the 1980s, the combination of heavy hurricane flooding, new laws and wastewater treatment reduced pollution and opened the river to spawning shad. Shad today are prized as gamefish and (along with their roe) for eating. A relative of herring, part of its scientific name, sapidissima, means "most savory" in Latin. ### Top of Page