Functional check of three river bottom slides in the river Ulster near Buttlar In this project, the functionality of three consecutive river bottom slides in the river Ulster near Buttlar will be reviewed. Part of this project is to develop and test a new method to minimize the human and financial efforts of such an investigation. Tagging the fish in the investigation area and recapture them at the upper river bottom slide should be sufficient to evaluate the functionality of each of the three individual constructions. A new developed guiding system, which extends over the entire cross section of the river, can make this possible. With the results so far and the great resistance of the fishing gear to strong floods can be expected a positive rating of the new technique and a wide range of applications in the future.