Rahway River migrations. Fish ladders are inundated structures with small underwater steps that allow fish to navigate around a dam and continue their migration. Other approaches include removing obstructions that are inoperative or no longer serve their purpose, or improving water quality and reducing debris that obstructs passage. The fish targeted for upstream passage at the Rahway River Water Supply Dam are alewife (Alosa pseudoharengus), blueback herring (Alosa aestivalis), gizzard shad (Dorosoma cepedianum), white perch (Morone Americana) and the endangered American eel (Anguilla rostrate). Alewife and blueback herring are collectively referred to as river herring due to their similarity in appearance, range,
Sander (genus) Sander (genus) Sander (formerly known as "Stizostedion") is a genus of fish in the Percidae (perch) family. They are also known as "pike-perch" because of their resemblance to fish in the unrelated Esocidae (pike) family. Local names for the fish have been the basis for many geographical names, like River Suda in Russia or Saunags village on the Baltic coast. The genus includes the following 5 species: Phylogenetic relationships of the species of genus "Sander" based on the concatenated data set of six gene regions and a Bayesian analysis. "Romanichthys valsanicola" is the nearest living relative of the genus "Sander"