Prymnesium parvum is a toxin producing microalgae that causes devastating algal blooms globally. The Norfolk Broads has suffered from almost annual occurrences of P. parvum blooms since the early 1960s, with the possibility that many more undocumented events occurred prior to this. Blooms of P. parvum result in massive fish mortalities, leading to severe economic damage to the Norfolk Broads and the surrounding environment which is usually a hot spot for angling and tourism.

This website has been put together as part of a collaborative project between members of the Norwich Research Park, The Environmental Agency, Norfolk Pike Anglers and the Broads Authority, to develop a better understanding of this fish-killing pathogen.