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,
Guinean sea catfish Guinean sea catfish The Guinean sea catfish (Carlarius parkii), also known as the Marine catfish, is a species of sea catfish in the family Ariidae. It was described by Albert Günther in 1864, originally under the genus "Arius". It is a tropical fish which is found in Mauritania, Angola, Morocco and the Spanish Sahara. It inhabits coastal marine waters at a depth range of , also frequently entering estuaries and freshwater rivers. It reaches a maximum total length of , more commonly reaching a TL of . The Guinean sea catfish feeds on bony fish and shrimp. It is of