Pontic shad Pontic shad The Pontic shad ("Alosa immaculata", previously "Alosa pontica"), also referred to as the Black Sea shad or Kerch shad, is a species of clupeid fish in the genus "Alosa", native to the Black Sea and Sea of Azov basins. "Alosa immaculata" lives in the Black Sea and Sea of Azov, and adults migrate up rivers to spawn. It may also be found in the Marmara Sea in Turkey. It currently migrates up and spawns in six rivers: the Danube, Dnieper, Dniester, Southern Bug, Don and Kuban Rivers. Previously the migrations reached far upstream, up to 1,600 in Danube
Columbia River supports several species of anadromous fish that migrate between the Pacific Ocean and fresh water tributaries of the river. Sockeye salmon, Coho and Chinook (also known as "king") salmon, and steelhead, all of the genus "Oncorhynchus", are ocean fish that migrate up the rivers at the end of their life cycles to spawn. White sturgeon, which take 15 to 25 years to mature, typically migrate between the ocean and the upstream habitat several times during their lives. Salmon populations declined dramatically after the establishment of canneries in 1867. In 1879 it was reported that 545,450 salmon, with an average weight