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,
Fish Hook River Fish Hook River The Fish Hook River, also spelled Fishhook River, is a tributary of the Shell River, long, in north-central Minnesota in the United States. The river's source, Fish Hook Lake, collects short tributaries known as the Portage River and the Potato River. Via the Shell and Crow Wing rivers, the Fish Hook River is part of the watershed of the Mississippi River. The river flows for its entire length in southwestern Hubbard County; its watershed extends into northeastern Becker County. Its name is a translation of the Ojibwe name for the river and Fish Hook Lake, "Pugidabani". The