The first data paper from CoastNet was published in Frontiers in Marine Science. This work presents some of the most important databases of estuarine fish, included in the “Historical Data” section of the CoastNet geoportal. The projects that were at their origin are also described and the potential use of this type of data are discussed. We hope this paper might be useful for future users of the geoportal, looking for these data. To know more, click here.