An international team of scientists discovered three historical shipwrecks during an underwater archaeological expedition last year in the Mediterranean Sea.
The expedition also gathered high-resolution images of three Roman wrecks initially discovered by oceanographer Robert Ballard and archaeologist Anna Marguerite McCann in the 1980s to 2000s. Researchers' findings were presented Thursday during a UNESCO press conference in Paris.
Twenty scientists from Algeria, Croatia, Egypt, France, Italy, Morocco, Spain and Tunisia set out on French research vessel the Alfred Merlin on a 14-day voyage between August and September.
© Provided by CNNScientists conducted their expedition in the Mediterranean last year aboard the Alfred Merlin research vessel. - M. Pradinaud
Using remotely operated underwater vehicles, called ROVs, the researchers explored the Skerki Bank of Tunisia and Italy's Sicilian Channel.
The team used the research vessel's underwater mapping and imaging equipment to catalog shipwrecks, dating from ancient times to the 20th century, with sonar.
The ROVs dived to depths inaccessible to humans to collect images and video of the wrecks and their artifacts. One ROV, named Arthur, was able to reach depths of 2,296 to 2,952 feet (700 to 900 meters).
Located along a heavily traveled route in the Mediterranean, the Skerki Bank in the Strait of Sicily is one of the most treacherous maritime areas. Its shallow waters feature an intensely rocky seabed, some of which is less than 3.2 feet (1 meter) beneath the water's surface.
© Provided by CNNRocky features can be seen just beneath the surface of Keith Reef. - Angel Fitor/UNESCO
The Skerki Bank's perilous features have caused shipwrecks for more than 3,000 years, sinking ancient trading vessels as well as ships during World War II. The area is of interest to researchers because the route has served as a point of contact between multiple cultures traversing the Mediterranean.
An ROV named Hilarion descended through the most dangerous zone of the Skerki Bank called Keith Reef to conduct the first detailed study of the ocean floor. Resting along the bottom of the Tunisian continental shelf were three ships, all previously unknown to researchers.
Two of the shipwrecks were likely from the end of the 19th century or beginning of the 20th century, including a "large motorized metal wreck" with no traces of cargo. In that wreck, researchers noted that the davits, which would have been used to lower lifeboats, were facing outward, which means any crew may have been able to leave the ship. The second ship was likely a wooden fishing boat.
© Provided by CNNOne of the shipwrecks on the Tunisian continental shelf can be seen in this image. - DRASSM UNESCO
A third shipwreck was likely a merchant vessel that sailed between the first century BC and the second century. The ROV spotted artifacts that appeared to be amphoras, or tall, two-handled jars with narrow necks used by Greeks and Romans, possibly to store wine.
The team hopes that looking through archives could reveal the individual names of the ships that sank since none of them was easily identifiable.
Meanwhile, exploration along the Italian continental shelf revisited three Roman shipwrecks dating between the first century BC and the first century, including two merchant vessels and one cargo ship. All three littered artifacts across the seafloor, including amphoras, ceramics, building materials, jugs, pots and lamps.
The items were likely part of trade between cultures that crisscrossed the Mediterranean thousands of years ago.
© Provided by CNNRoman shipwrecks on the Italian continental shelf included handled jars called amphoras. - V.Creuze ROV Drassm/UNESCO
"We are going to write a new page in the history of trade," said Barbara Davidde, underwater archaeologist and director for the national superintendency for underwater cultural heritage in Italy. "Thanks to the analysis of the cargo, we can study the relationships between the countries in the Mediterranean and the sea trade that connected different parts of the Mediterranean."
The shipwrecks and their artifacts surprisingly remained largely undisturbed since being discovered between 1988 and 2000.
The wrecks were initially outside territorial waters, meaning that their artifacts were easy targets for looting. Now, the areas around the wrecks will be protected under UNESCO's 2001 Convention on the Protection of the Underwater Cultural Heritage.
© Provided by CNNCeramics were found scattered across the seafloor from an ancient Roman shipwreck. - V.Creuze ROV Drassm/UNESCO
The designation will allow for more precise mapping of shipwrecks and defining protection zones.
"We recognize the huge potential and the importance of underwater cultural heritage," said Lazare Eloundou Assomo, director of the UNESCO World Heritage Centre.
"UNESCO has actively committed itself to supporting underwater archaeological missions of this type right across the globe. As you know, the Mediterranean with its very rich history, and its countless shipwrecks and archaeological sites offer a unique and fascinating stage for such expeditions. And I hope that there will be many more in the future that will bring us together."
For more CNN news and newsletters create an account at CNN.com