Ancient Black Sea shipwrecks  Ancient Black Sea shipwrecks found in the Black Sea date to Antiquity. In 1976, Willard Bascom suggested that the deep, anoxic waters of the Black Sea might have preserved ships from antiquity because typical wood-devouring organisms could not survive there. At a depth of 150m, the Black Sea contains insufficient oxygen to support most familiar biological life forms. Originally a land-locked fresh water lake, the Black Sea was flooded with salt water from the Mediterranean Sea during the Holocene. The influx of salt water essentially smothered the fresh water below it because a lack of internal motion and mixing meant that no fresh oxygen reached the deep waters, creating a meromictic body of water. The anoxic environment, which is hostile to many biological organisms that destroy wood in the oxygenated waters, provides an excellent testing site for deep water archaeological survey. In a series of expeditions beginning around 2000, the NOAA Ocean Exploration program led by Robert Ballard identified what appeared to be ancient shorelines, freshwater snail shells, and drowned river valleys in roughly of water off the Black Sea coast of modern Turkey. The team discovered three ancient wrecks to the west of the town of Sinop at depths of . Wreck A and Wreck C probably date to the late Roman period (2nd-4th century AD), while Wreck B probably dates to the Byzantine period (5th to 7th century AD). To the east of Sinop, the team discovered a remarkably well-preserved wreck at a depth, in Black Sea's deep anoxic waters. The vessel's entire hull and cargo are intact, buried in sediments. Its deck structures are also intact, including a mast rising some into the water column. Radiocarbon dating of wood from the wreck provides a date of 410-520 AD This ship has been named "Sinop D" by the Ballard team. In 2008, Ballard and his team conducted an expedition that focused on the exploration of the sea bed about 15–30 km west of Sinop, and an additional deep-water survey east and north of the peninsula. Their project had several goals. They sought to discover whether human habitation sites could be identified on the ancient submerged landscape, to examine the sea-bed for shipwrecks (where they found Sinop A-D), to test the hypothesis that the anoxic waters below 200m would protect shipwrecks from the expected biological attacks on organic components, and to seek data about an ancient trade route between Sinop and the Crimea indicated by terrestrial archaeological remains.