FL - Archaeologists dive into Florida’s past and find lessons on adapting to future sea rise
Unlike almost any other archaeologist on earth, Jessi Halligan does her digging underwater.
Halligan, an associate professor of anthropology at Florida State University, studies the first people who came to Florida about 15,000 years ago, when sea levels were 300 feet lower than they are today. These days, many of Florida’s oldest settlements, hunting grounds and ceremonial mounds are at the bottom of rivers or the Gulf of Mexico. Florida is one of the global epicenters for a little-known field called “submerged landscape archaeology.”
There are only about a dozen full-time scientists working in the field in the U.S. They tend to focus on Florida because the state has lost half its landmass to sea level rise since humans started living here. Scientists have found evidence of ancient shell mounds as far as 20 miles into the Gulf, one of thousands of preserved archaeological sites hidden under the state’s gentle rivers and along the wide, shallow continental shelf that stretches 200 miles off the state’s west coast.
Sea levels have risen 300 feet in Florida since people first arrived 15,000 years ago, shrinking the state’s landmass by half.
The stories that archaeologists like Halligan unearth from the depths offer lessons for modern Floridians who are now facing sea level rise once again. Jessi Halligan, an associate professor of anthropology at Florida State University, prepares to dive in the Aucilla River in search of artifacts from the first people who occupied Florida. Brendan Fenerty Courtesy of the Center for the Study of the First Americans (CSFA)
“Across space and time in human history, water always wins. So we have to learn to accept that and be creative with it,” said Halligan. “Flexibility is the watchword. You have to build structures that can move and can bend — or be willing to say goodbye to them.”
“For cities like Miami and St. Pete and Jacksonville, that’s going to come to a pretty major reckoning,” said Morgan Smith, an associate professor of anthropology at the University of Tennessee, Chattanooga who studies underwater sites in the Apalachee Bay in North Florida. “Native peoples had to adapt, and they were able to do it because they had that flexibility in their lifestyle… We’re going to have to do it also, and it’s going to be a lot more complicated.”
Studying artifacts found underwater in Florida has already rewritten the history of human migration in North America. In 2016, Halligan led a team of researchers that found a stone knife buried under 13 feet of sediment at the bottom of the Aucilla River, which drains into Apalachee Bay. It provided evidence that people were living in Florida 14,500 years ago — a millennium earlier than scientists previously assumed the first people arrived in the Americas.
So far, Halligan, Smith, and other scientists have identified about 50 underwater archaeological sites in Florida. Soon, some of these sites may become the first submerged landscapes to be added to the National Register of Historic Places. But the researchers have only surveyed about 1 percent of the Gulf, and they suspect there are thousands of Florida sites left to find.
“Imagine having a 500 piece jigsaw puzzle and you have like 10 pieces and none of them are corners,” said Matthew Newton, an anthropology PhD student at the University of Florida who studies underwater archaeology. “That’s archaeology, and that’s especially how offshore archaeology is. It’s a huge ocean.”
