![enter image description here][2] This project contains the secondary biodiversity database of *Golfão Maranhense (Maranhão, Brazil)* presented in the article "Retrieving biodiversity data from multiple sources: making secondary data standardized and accessible". Data were retrieved from eight biotic groups (birds, amphibians, reptiles, mammals, fishes, phytoplankton, benthos and plants) found in the specialized platforms Science Direct and Google Scholar, public data repositories (GBIF, VertNet, Wikiaves, SpeciesLink) and technical reports. See the Files section for all corresponding spreadsheets. A total of *76 variables* were extracted from the studies. Of these, 59 were standardized using the [Darwin Core standard][3] (DwC), while 17 variables required adaptation. To accommodate the variables not covered by the DwC standard, we developed the ITV-core standard, incorporating terms such as the species' conservation status. These variables have been grouped into three main categories: - (a) General Information - data on the published paper, such as title, year, keywords, and study objectives; - (b) Sampling Events - information on when and where the target taxa were sampled, such as date, sampling method, location, and geographic coordinates; - (c) Occurrences - description of the collected individual, such as epithet, life stage, and conservation status. The species' conservation status was sourced from the International Union for Conservation of Nature (IUCN) and the Brazilian Ministry of the Environment (MMA), and applies at the species level rather than the individual level [1]: https://ibb.co/MB5Km96 [2]: https://files.osf.io/v1/resources/gh9ym/providers/osfstorage/66e1d5fcb95c8fd1e3a3c9a3?mode=render [3]: https://dwc.tdwg.org/