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,
Pelecus cultratus Pelecus cultratus Pelecus cultratus, known variously as the sichel, the ziege, the sabre carp or sabrefish, is a species of cyprinid fish from an Eastern Europe and adjacent Asian regions. It is the only species of its genus. This species inhabits lower reaches of rivers and brackish waters of eastern Baltic, Black, Caspian and Aral Sea basins. This fish has no major threats and the IUCN lists it as being of "Least Concern". The ziege resembles a large Baltic herring in appearance. It grows to about in length. It has a keel on its belly which from the side looks