Designated on November 16, 1990, Florida Keys National Marine Sanctuary is one of 15 marine protected areas that make up the National Marine Sanctuary System. Administered by NOAA, a federal agency, and jointly managed with the State of Florida, Florida Keys National Marine Sanctuary protects 2,900 square nautical miles of waters surrounding the Florida Keys, from south of Miami westward to encompass the Dry Tortugas, excluding Dry Tortugas National Park. The shoreward boundary of the sanctuary is the mean high-water mark, essentially meaning that once you set foot in Keys waters, you have entered the sanctuary. Within the boundaries of the sanctuary lie spectacular, unique, and nationally significant marine resources including North America's only coral barrier reef, extensive seagrass beds, mangrove-fringed islands, and more than 6,000 species of marine life. The sanctuary also protects pieces of our nation’s history such as shipwrecks and other archeological treasures.