The term territorial waters is sometimes used informally to refer to any area of water over which a sovereign state has territorial sea, a contiguous zone, the extended continental shelf. In a narrower sense, the term is used as a synonym for the territorial sea.
Territorial seas take the vast store of the ocean's wealth together with riches. Extending up to 12 nautical miles from shore, these coastal waters constitute only ~6% of the sea—yet they are where the ocean's highest concentrations of biodiversity intersect with the areas of highest human need. Territorial seas are domestic to 100% of the world's mangroves, sea grass beds, together with kelp forests, and 83% of the world's coral reefs.