Posted on Tuesday 21 January 2003

Many interesting things await discovery at the bottom of the Black Sea.

Researchers announced today their discovery of the shipwrecked remains of an ancient trading vessel over 2,300 years old that sank in the Black Sea off the coast of present-day Bulgaria. The vessel dates to the 5th to 3rd century B.C., an era known to scholars as the classical period of ancient Greece—the time of Plato when Athens reached the height of power and Zeus was believed to rule the celestial firmament. The shipwreck is the oldest ever found in the Black Sea. It joins a relatively small handful of other known shipwrecks of the Greek period... Hiebert postulates that the ship may have begun its journey on the south coast of the Black Sea, sailed north across the sea following prevailing currents to the Crimean peninsula, where it loaded its amphora with freshwater catfish, then sailed west along the northern coast of the Black Sea bound for Greece. "This allows us to construct an idea of what Black Sea trade would have been like in the 5th to 4th century B.C.," said Hiebert. "We find many similarities between the southern coast of the Black Sea and the northern coast of the Black Sea. Now we're finding those same similarities with the western coast of the Black Sea," said Hiebert. Hiebert indicated that a growing body of archaeological research in the region is leading scholars to revise their understanding of the Black Sea as a central—rather than peripheral—region of maritime culture. "This is changing our textbooks because here we have a whole culture area that we have to consider. For [those of] us in archaeology and ancient history, this is very exciting," he said. The researchers said they are anxious to return to wreck later this summer to map and excavate the site and gather more amphora samples to further test their hypothesis. "From text and archaeology we've been able to learn quite a bit about the Greek presence in the Black Sea and about the interaction of the Greeks with the people who were already living. But it's only been through indirect evidence that we've been able to approach the trade networks that existed," said maritime archaeologist Cheryl Ward, an assistant professor of archaeology at Florida State University in Tallahassee who has also worked closely with Ballard and Hiebert in the Black Sea region. "This shipwreck provides the first opportunity to see [direct evidence of] that early trade in action."... Crossroads of the Ancient World The Black Sea region has long intrigued undersea explorers and archaeologists. The region lay at the crossroads of ancient Europe, Asia, and the Middle East. Evidence suggests that the region was a center of maritime trade for millennia, stretching from Roman and Greek times as far back as the Bronze Age. The Black Sea is also the only sea with a deep-water anoxic layer, oxygen-deprived waters where wood-boring mollusks cannot survive. Because of this, wooden shipwrecks of antiquity can remain in a high state of preservation for thousands of years. The 70-year reign of the Soviet-era Iron Curtain during most of the 20th century prevented many Western explorers and archaeologists from conducting research in much of the Black Sea. "It has only been since the fall of the Soviet Union and the opening of the Black Sea as an economic unit as we see it today that we're able to actually go in and study [the region] as it actually was in the ancient world—a sort of maritime province itself," said Hiebert. "We're just beginning our research," Hiebert said. "It's only time before an older shipwreck is found." [More...]

The Black Sea is an exciting area for marine archaeology because it is anoxic (i.e. without any dissolved oxygen) and impregnated with Hydrogen sulphide (H₂S). While this has a corrosive effect on metal, it does a good job in preserving organic material. Why is it annoxic? Paradoxically, it's because the Black Sea is fed by so many fresh-water rivers:

[I]t is the rivers which dominate the Black Sea. Only three major rivers - Rhône, Nile and Po - run into the far bigger Mediterranean. But the Black Sea receives five: the Kuban, the Don, the Dnieper, the Dniester and, above all. the Danube whose drainage basin extends across the whole of eastern and central Europe aid almost to the borders of France. The Danube alone carries 203 cubic kilometric of fresh water into the Black Sea every year, more than the entire flow of river water into the North Sea. It is these rivers, source of so much life, which over tens of thousands of years extinguished life in the Black Sea depths. The inrush of organic matter from the rivers was too much for the bacteria in sea-water which would normally decompose it. They feed by oxidizing their nutrients, using the dissolved oxygen normally present in sea-water. But when the organic inflow is so great that the supply of dissolved oxygen is used up, then the bacteria turn to another biochemical process: they strip the oxygen from the sulphate ions which are a component of sea-water, creating in this process a residual gas: hydrogen sulphide, or H₂S. This is one of the deadliest substances in the natural world. A full breath of it is usually enough to kill a human being. Oil workers know and dread it; they watch for its rotten-eggs reek and at the first whiff they run. They are right to do so. Hydrogen sulphide almost instantly destroys the sense of smell, so that after the just sniff it is impossible to tell whether one is inhaling more. The Black Sea is the world's biggest single reservoir of hydrogen sulphide. Below a fluctuating depth of between 150 and 200 metres, there is no life. The water is anoxic, without dissolved oxygen, and impregnated with H₂S; because much of the Black Sea is deep, this means that some 90 per cent of the Sea's volume is sterile. It is not the only place in the oceans where H₂S has accumulated. There are anoxic areas on the floor of the Baltic Sea, and under some Norwegian fjords where water circulation is slight. Off the Peruvian coast, hydrogen sulphide is sometimes brought welling up from the depths to the surface in the periodic catastrophes known as ('el Nino', where it kills the entire ecosystem, destroying the coastal fisheries and reacting with paint on ships' bottoms to turn them black (the 'Callao Painter' effect). But the Black Sea deeps remain the largest mass of lifeless water in the world. And yet, until the last hundred years, the Black Sea has seemed to human beings a place of almost monstrous abundance. The poisonous darkness lay far below, unknown to anyone. Above the hundred-fathom line, the 'haloclyne' or 'oxyclyne' which marks the upper limit of anoxia, the Sea boiled with life. Salmon and huge sturgeon - the beluga can reach the length and weight of a small whale - crowded up the big rivers to spawn (caviar was so plentiful that in fourteenth-century Byzantium it was the food of the poor).

Black Sea : The Birthplace of Civilisation and Barbarism by Neal Ascherson, Vintage 1996 pages 4 - 5