Marine Regions is the authoritative reference for marine geographic boundaries and place names — the ocean equivalent of GADM for land boundaries, maintained by the Flanders Marine Institute (VLIZ) in partnership with IOC-UNESCO.
The flagship product is the EEZ (Exclusive Economic Zone) layer: the boundaries that define each country's 200-nautical-mile zone of sovereign rights over marine resources. For any analysis involving fishing rights, offshore energy, maritime jurisdiction, or ocean governance, EEZ boundaries are foundational. Marine Regions provides the current version of these boundaries, continuously updated as disputed claims are resolved and new international agreements are reached.
Beyond EEZs, the database covers the full spectrum of marine administrative and geographic units. IHO Sea Areas define named bodies of water (North Sea, Arabian Sea, Coral Sea) according to the International Hydrographic Organization's standard. ICES statistical rectangles are used for fisheries reporting across the North Atlantic. Large Marine Ecosystems define ecologically coherent ocean regions used in conservation planning. Longhurst provinces characterize oceanographic provinces based on productivity patterns.
For ocean biodiversity analysis, Marine Regions integrates with the Ocean Biodiversity Information System (OBIS) and World Register of Marine Species (WReMS) — all using the MRGID identifier system to enable consistent cross-database linking. A species occurrence record in OBIS references the same marine region as a fishing effort record from Global Fishing Watch, allowing multi-source synthesis.
The data is routinely used in research on high seas governance (analysis of activities outside any national EEZ), climate change impacts on fisheries (overlaying projected habitat shifts with EEZ boundaries), marine protected area effectiveness (what proportion of a country's EEZ has protection?), and offshore energy development permitting.
All boundary files are available as shapefiles and GeoJSON through the Marine Regions download portal, with WFS/WMS endpoints for live integration in web mapping applications.
