Alosa kessleri the dam, and the population is now abundant. The species may be threatened by commercial and illegal fishing in the Caspian Sea and at the mouth of the Volga during the migration, though. Alosa kessleri Alosa kessleri, also referred to as the Caspian anadromous shad, the blackback, or the black-spined herring, is a species of clupeid fish. It is one of the several species of shad endemic to the Caspian Sea basin. This is an anadromous species which ascends from the Caspian to the Volga river up to the Volgograd to spawn. Before the construction of th Volgograd dam it
Mattapoisett River mill purposes" and featured three herring weirs; the "Upper Herring Weir" in Rochester, the "Middle Weir" or "Church's Weir", and the "Lower Herring Weir" at the entrance to Mattapoisett Harbor. Fish populations drastically declined during the twentieth century until they were almost extinguished, but local restoration efforts from the 1980s onwards have fostered a slow recovery. The principal restoration tactic has been to remove snags and other obstacles from the river that serve to impede fish migrations. The Lower Herring Weir is one of the few rivers emptying into Buzzards Bay that has electronic fish counters installed. Reports from Alewives