We have collated a database of 239 reports of freshwater mussel mass mortality events (MMEs) across Europe. This database was collated by sending questions to around 30 co-authors researching mussels in Europe. I have investigated this database to answer questions about the distribution of MMEs across Europe, the causes of MMEs, the species impacted by MMEs, and the timeframes of MMEs, among others. As part of this project, we have also developed a survey to differentiate the confidence reporters have in the cause they attribute to a certain event.