The Monitoring of fishes and crustaceans by Province East Flanders in Flanders, Belgium is an sampling event dataset published by the Province East Flanders (Belgium). The data are collected from targeted monitoring on non-navigable watercourses, from 1985 onwards. Earlier collected data was digitized afterwards, newly collected data is digitized immediately. Only non-threatened species are presented in this dataset. The data are published as a standardized Darwin Core Archive and includes for each occurrence record an occurrenceID, date, location, quantification, length, weight where available and scientific name. Also the physico-chemical parameters of the watercourses at that moment are given when available. Issues with the dataset can be reported at https://github.com/riparias/pov-fishes-occurrences/issues We have released this dataset to the public domain under a Creative Commons Attribution License. We would appreciate it if you follow the INBO norms for data use (https://www.inbo.be/en/norms-data-use) when using the data. If you have any questions regarding this dataset, don't hesitate to contact us via the contact information provided in the metadata or via opendata@inbo.be.