Explorers accidentally find a graveyard of more than 40 perfectly preserved ancient shipwrecks at the bottom of the Black Sea

In the depths of the Black Sea lies a landscape of complete darkness, where there is no light and no oxygen.

Archaeologists have long believed this 'dead zone' holds of a perfectly preserved graveyard of shipwrecks.

Now, a mapping expedition has proved them right, after accidentally uncovering more than 40 ancient shipwrecks from the Ottoman and Byzantine periods.  

More than 40 shipwrecks have been discovered from the Ottoman and Byzantine periods, many of which provide the first views of ship types known from historical sources. Pictured is a shipwreck from the Ottoman period

BLACK SEA'S 'DEAD ZONE'

With no light and no oxygen in the Black Sea's lower, anoxic layer, no life can survive.

This means the environment cannot support the organisms that typically feast on organic materials, such as wood and flesh.

As a result, there is an extraordinary opportunity for preservation, including shipwrecks and the cargoes they carried.

The expedition has been scouring the waters 5,900ft (1,800 metres) below the surface of the Black Sea using an off-shore vessel equipped with some of the most advanced underwater equipment in the world.

The vessel is on an expedition mapping submerged ancient landscapes which were inundated with water following the last Ice Age.

The project, known Black Sea Maritime Archaeology Project (Black Sea MAP), involves an international team led by the University of Southampton's Centre for Maritime Archaeology.

Professor Jon Adams, principle investigator on the project, said: 'We're endeavouring to answer some hotly-debated questions about when the water level rose, how rapidly it did so and what effects it had on human populations living along this stretch of the Bulgarian coast of the Black Sea. 

'The primary focus of this project is to carry out geophysical surveys to detect former land surfaces buried below the current sea bed, take core samples and characterise and date them, and create a palaeoenvironmental reconstruction of Black Sea prehistory.'

The vessel is based on board the Stril Explorer, and carries some of the most advanced underwater survey systems in the world.

The researchers are using two Remotely Operated Vehicles (ROVs) to survey the sea bed.

The researchers used two Remotely Operated Vehicles (ROVs) to survey the sea bed. These have discovered several wrecks, including this one from the Byzantine period (pictured)

The wrecks, such as this one from the Medieval period, are astonishingly well preserved due to the anoxic conditions (absence of oxygen) of the Black Sea below 150 metres

BLACK SEA'S HISTORY

Many of the colonial and commercial activities of ancient Greece and Rome, and of the Byzantine Empire, centred on the Black Sea. 

After 1453, when the Ottoman Turks occupied Constantinople (and changed its name to Istanbul), the Black Sea was virtually closed to foreign commerce. 

Nearly 400 years later, in 1856, the Treaty of Paris re-opened the sea to the commerce of all nations.  

One is optimised for high resolution 3D photography, while the other, called Surveyor Interceptor, 'flies' at four times the speed of conventional ROVs and carries an entire suite of geophysical instrumentation, as well as lights, high definition cameras and a laser scanner.

Since the project started, Surveyor Interceptor has set new records for depth at 5,900ft (1,800 metres) and sustained speed  of over six knots (7mph), and has covered 1,250 kilometres (776 miles).

Among the wrecks are ships from the Ottoman and Byzantine Empires, which provide new information on the communities on the Black Sea coast.

Many of the colonial and commercial activities of ancient Greece and Rome, and of the Byzantine Empire, centred on the Black Sea. 

After 1453, when the Ottoman Turks occupied Constantinople (and changed its name to Istanbul), the Black Sea was virtually closed to foreign commerce. 

Nearly 400 years later, in 1856, the Treaty of Paris re-opened the sea to the commerce of all nations. 

Professor Adams said: 'The wrecks are a complete bonus, but a fascinating discovery, found during the course of our extensive geophysical surveys. 

The Remotely Operate Vehicles captured the shipwrecks in stunning detail, including this intricate stern of a ship from the Ottoman period

While the primary focus of the project is to carry out geophysical surveys, shipwrecks, including this one from the Ottoman period, have given new insights into how communities live on the shores of the Black Sea

The exploration vessel is based on board the Stril Explorer, and carries some of the most advanced underwater survey systems in the world

'They are astonishingly preserved due to the anoxic conditions (absence of oxygen) of the Black Sea below 150 metres. 

'Using the latest 3D recording technique for underwater structures, we've been able to capture some astonishing images without disturbing the sea bed.

'We are now among the very best exponents of this practice methodology and certainly no-one has achieved models of this completeness on shipwrecks at these depths.'

SCANNING THE BLACK SEA BED 

The researchers are using two Remotely Operated Vehicles (ROVs) to survey the sea bed.

One is optimised for high resolution 3D photography, while the other, called Surveyor Interceptor, 'flies' at four times the speed of conventional ROVs and carries an entire suite of geophysical instrumentation, as well as lights, high definition cameras and a laser scanner.

Since the project started, Surveyor Interceptor has set new records for depth (1,800 metres) and sustained speed (over six knots (seven miles/hour)), and has covered 1,250 kilometres (776 miles).

A collection of more than 40 shipwrecks have been discovered and inspected, many of which provide the first views of ship types never seen before.

Among the wrecks are ships from the Ottoman and Byzantine Empires, which provide new information on the communities on the Black Sea coast.

This Remotely Operated Vehicle, called the 'Work Class Supporter' is designed to capture high resolution 3D photography and video

The project has been scanning the bottom of the Black Sea, and has so far covered 1,250 kilometres (776 miles)

The Surveyor Interceptor 'flies' at four times the speed of conventional ROVs and carries an entire suite of geophysical instrumentation, as well as lights, high definition cameras and a laser scanner