Yearly Report of the Migratory Fish Working Group
For the second consecutive year the migratory brown trout by-catch of professional fishery has remained at a low level (only 2.5 t). The total of migratory brown trout caught by recreational fishery was 0.6 tons, which means a decrease of 43.4% compared to the previous year. The video surveillance system in the fish ladder of the hydro-electric power plant “Reichenau” (Alpenrhein) was exchanged last year, data are only available for the last quarter of 2017. According to expert assessment, no significant changes are noticed compared to the previous year (727 Ind.). For the first time, the number of ascending migratory brown trout at the hydroelectric power plant “Hochwuhr” (Ill) was included in the annual report. The 126 ascending migratory brown trout registered, signify an increase compared to the previous year (90). The management concept for Lake Constance migratory brown trout presented at the IBKF 2017 has received such broad interest, that the edition of 1,500 exemplars is already sold out. In addition, the concept for a baseline survey on the expansion of the particularly vulnerable common nase (Chondrostoma nasus) was developed for the Lake Constance basin.