The vendace (coregonus oxyrhynchus) is a migratory coregon species that spawns in the sandy or gravelly stretches of medium-sized rivers (generally the barbel region). The young fish probably migrate fairly soon to the estuary (the brackish water zone). It is thought that they reach adulthood in the extensive transitional waters close to the ocean or the Wadden Sea. In earlier times the Rhine vendace was caught by professional fishermen in the Lower Rhine and its tributaries. After the Rhine vendace died out, a stock replenishment scheme was started with the help of stock donated from the North German and Danish populations of the North Sea vendace. Today a large population of vendace has been found in the Netherlands, above all in the Ijsselmeer Sea, and in the year 2005 the first fish migrating upriver for spawning was registered on the Lower Rhine, near Wesel. There are good grounds for hoping that reproductive populations of the fish may be reestablished. Here, though, we need to know more about the lifecycle of the species, and effective measures must also be taken to control pollution.
