HELCOM collects monitoring data and data related to the Baltic Sea into various different thematic databases.
- HELCOM COMBINE database contains data of oceanographic monitoring data gathered by HELCOM Contracting Parties within the COMBINE monitoring programme. Data about concentrations of hazardous substances in water, sediment and biota can be accessed under DOME database.
- HELCOM Biodiversity database contains macrospecies observation data made available by HELCOM Contracting Parties from a single entry point.
- HELCOM PLC Database contains all waterborne nutrient and contaminant discharges stemming from HELCOM pollution load monitoring.
- HELCOM MPA Database (former Baltic Sea Protected Areas (BSPA) database) is designed to centralise relevant information on the Baltic Sea Protected Areas. The database includes general information on the sites and their management plans, as well as lists of species, biotopes, and biotope complexes.
- HELCOM MORS Environmental database contains levels of radioactivity monitored in water, sediment and biota in the Baltic Sea.
- HELCOM MORS Discharge database contains data reported by HELCOM Contracting Parties on airborne and waterborne discharges resulting from nuclear facilities in the Baltic Sea and North Sea region
- HELCOM Coastal fish core indicator database (COOL) contains data collected from coastal fish monitoring and used for coastal fish core indicators.
- HELCOM/ASCOBANS Harbour porpoise database contains observations of sightings, by-catches and strandings as reported by HELCOM Contracting Parties. Data is available from HELCOM Biodiversity database .