When English settlers first established the Jamestown settlement on the shores of what is now Virginia, they came hoping that the “New World” would be a pearl among the British colonies. However, USF researchers have discovered that it was the oysters themselves that kept the colonists alive and the shells that would tell their story hundreds of years after they had died.
The Jamestown fort, which historians had originally thought washed away, was discovered in 1994 by William Kelso, the director of archaeology for the Association for the Preservation of Virginia Antiquities’ (APVA) Jamestown Discovery Project.
Upon his discovery, Kelso began sending artifacts to scientists around the country to interpret the events that shaped the colony.
Among the discoveries were maps – left behind in the journals of colonists – that revealed wells containing shucked oyster shells. These shells were given to USF geologist Gregory Herbert.
“The Jamestown fort was thought to be lost until just a few years ago,” said Herbert, who co-authored an article titled “Reconstructing Early 17th Century Estuarine Drought Conditions from Jamestown Oysters.” “Archeologists previously thought that the colonists were inept, that they were incapable of surviving on their own. We started making the assumption that maybe it was really bad circumstances – really bad climate.”
When examining the oyster shells, USF scientists used a paper written by David W. Stahle in 1998 that used tree rings to study the affects of a drought lasting from 1606-12 – the most severe drought the area had experienced in 800 years.
By studying the annual cycles, or rings, preserved in the skeletal biological remains of the oysters in a process known as sclerochronology, Herbert and USF Ph.D. candidate Jennifer Silko were able to verify Stahle’s claims.
“The oxygen isotopes of the oysters give off the saltwater content, and the carbon content shows us where they were getting their oysters,” Herbert said. “The more severe the drought, the higher the salt content.”
Juliana Harding of the Department of Fisheries Science at the Virginia Institute of Marine Science said the drought could be behind the mysterious disappearances of settlers in the “Lost Colony” of Roanoke.
“The lost colony didn’t make it – Jamestown made it and that speaks for the fortitude of the people,” Harding said. “It shows that they worked hard, they tried hard and they did the best they could with what they had.”
Herbert and Harding said they believe the oysters saved the lives of the Jamestown colonists, who would have lost many crops and other land resources because of the drought.
According to the American Journal of Public Health, a dried oyster is 9 percent protein, and four or five provide the recommended daily allowance of iron, copper, iodine, magnesium, calcium, zinc, manganese and phosphorous. Oysters are also a good source of minerals and vitamins A, B and D.
The oyster shells, the artifacts found at the settlement and the analyzed tree rings all verify the date and existence of the drought, Harding said.
“It turns out that what the oysters said was going on … was also what the artifacts said was going on,” she said. “So the independence of the two storylines lends to credibility that we have the story right in a more robust fashion than if we hadn’t talked to each other.”