The goals of the proposed project are: 1. to develop a robust method and experimental set‐up to determine behaviour of fish in the vicinity of tidal turbines and collision risk in the strong turbid currents of the Marsdiep based on DIDSON technology, 2. to provide a first insight and measure avoidance and collision rate of fish (and although the focus will be on fish, also if marine mammals such as harbour porpoises and seals approach the device this will be determined within the project), 3. to develop data analysis methodology since analysing large DIDSON datasets manually is very labour‐intensive and will enhance the efficiency of future large scale studies using DIDSON