Mortality data of discarded undersized brown shrimp (Crangon crangon) from the commercial brown shrimp fishery along the German Wadden Sea coast. The data are part of the respective publication "Mortality rates of discard brown shrimp (Crangon crangon) in the North Sea coastal beam trawl fishery" submitted to Fisheries Research, where also the descriptions of the Methods will be found. The descriptions of the variables are given in each file in the "read.me"-sheet. The study was part of the CRANMAN project ("Research on the biology and fishery of North Sea shrimp CRANgon crangon as basis for an efficient self-management", period: 2018-2021) funded by the European Maritime, Fisheries and Aquaculture Fundnd the state of Lower Saxony (Germany).