Himberg M., von Numers M., Vasemägi A., Heselius S.-J., Wiklund T., Lill J.-O., Hägerstrand H. 2015. Gill raker counting for approximating the ratio of river- and sea-spawning whitefish, Coregonus lavaretus (Actinopterygii: Salmoniformes: Salmonidae) in the Gulf of Bothnia, Baltic Sea. Acta Ichthyol. Piscat. 45 (2): 125–131.

摘要

Background. The ability to distinguish between stocks in mixed fisheries is a prerequisite for a sustainable fisheries management. In the Gulf of Bothnia the relative contribution of endangered river-spawning and sea-spawning whitefish, Coregonus lavaretus (Linnaeus, 1758), to fisheries catches are currently not well known. This also applies to the southern Åland Islands, a major feeding ground for river-spawning whitefish from northern rivers. River- and sea-spawning whitefish are mixed while away from the breeding grounds and off the spawning season, and cannot be distinguished based on external features.