They found shipwrecks from the Archaic period (700-480 B.C.) to the Classical (480-323 B.C.) Hellenistic (323-31 B.C.) and Late Roman (about 300-600 A.D.) through the Early Modern Period (about 1750-1850).
"Overall, Late Roman vessels are still the predominant type, but we see that ships were traveling past Fourni in every time period," Campbell said.
The most significant shipwrecks of the 2016 campaign were a Late Archaic-early Classical wreck with amphoras from the eastern Aegean, a Hellenistic cargo of amphoras from Kos, three Roman cargos of Sinopean (carrot-shaped) amphoras, a wreck of North African amphoras of the 3rd-4th century AD, and a cargo of Late Roman tableware.
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The archaeologists also documented a large number of finds such as jettisoned pottery and ancient anchors. Indeed, two massive stone-stocks of ancient anchors dating to the Archaic period are the largest found in the Aegean so far.
"Some shipwrecks even carried goods from North Africa, Spain, and Italy," Campbell said.
He explained the high volume of ship traffic along the trade networks is the reason for the high concentration of wrecks found around Fourni.
"The small islands were really not unsafe. On the contrary, ships were making use of their many bays for shelter from winds and weather while traveling along the Eastern Aegean trade routes," Campbell said.
The archaeologists plan to continue the survey through 2018 to unveil what might be the largest concentrations of ancient shipwrecks in the world.
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"For comparison, the United States recently created a national marine sanctuary in Lake Michigan to protect 39 known shipwrecks located in 875 square miles. Fourni has 45 known shipwrecks around its 17 square mile territory," Campbell said.
So far the project, funded by the Honor Frost Foundation and Deep Blue Explorers, has covered less than 50 percent of Fourni's coastline. Many deepwater areas remain to be explored.
"We believe there are many more wreck sites to be found," Campbell said.
After mapping each wreck using photogrammetry to create 3D site plans, the project will consider excavating shipwrecks of significant scientific value.