| OBIS | Marine occurrence records and dataset provenance | OBIS — Ocean Biodiversity Information System |
| WoRMS | Accepted names, Aphia IDs, marine/brackish/freshwater flags | WoRMS — World Register of Marine Species |
| FishBase | Fish traits, common names, ecology context | FishBase |
| IUCN Red List | Conservation category and population trend context | IUCN Red List |
| Crossref | DOI metadata and publisher records | paper/ notes |
| OpenAlex | Work IDs, concepts, citations, related works | paper/ notes |
| Europe PMC / NCBI | Biomedical and environmental abstracts | paper/ notes |
| OpenCitations | Citation graph checks without paid keys | paper/ notes |
| NWIS / ERDDAP | Freshwater discharge, salinity, SST, and environmental context | finding/ notes |