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,
Indo-Pacific tarpon living in saltwater, growing just over , while saltwater examples grow over . They live upwards of 44 years and mature within two. They complete their metamorphosis from their larval stage in ten days. They are opportunistic feeders, feeding on smaller fish, crustaceans, and even plants rarely. In saltwater, they mainly feed on prawns and herring, but also many other small fish. In fresh water, no significant difference in their food habits is seen; they eat freshwater prawns and bony bream, mainly. The Indo-Pacific tarpon migrates between the open sea and inland rivers. As with all Elopiformes, it spawns mainly