Ten miles off the coast of Alabama lies an underwater forest with trees dating back to the ice ages.
After Hurricane Ivan in 2004, fisherman discovered something odd on their sonar, and enlisted the help of scientists to figure it out. Researchers found tree stumps dating back to 50,000 years ago.
“This is a very unique site, there’s nothing like it. To have trees this old that are very well preserved, you just don’t find these types of materials,” said associate professor of geography and anthropology Kristine DeLong. “During the ice ages, we had huge ice sheets over North America. Ice sheets kind of plow the whole surface so it doesn’t leave any record behind, so we don’t have a lot of records from this time period.”
One student collected sediment cores at the site and found a mite over 50,000 years old preserved in a sediment. Researchers have also found seeds that date back to the ice age, including bald cypress and grass seeds.
“Some people think that during the ice age everything got really cold and our forests would look more like a forest in Canada today here on the Gulf Coast,” DeLong said. “What we’re seeing from our site today is, no, it looked a lot like today.”
Researchers found palm tree stumps at the site. “You just don’t think about palm trees growing during the ice age, but I have the stumps,” DeLong said.
Researchers are working with scientists from the U.S. Geological Survey to determine how seeds have changed genetically from the ice ages to today.
“We’re also looking at pollen that’s in the sediments, and it tells us about which type of vegetation was growing at the time. It tells us a lot about what the northern Gulf of Mexico coast was like during the ice ages,” DeLong said. “What we’re seeing is that it’s not a whole lot different than it is today, but what’s interesting is we go more into the ice age and we start to see a shift in vegetation, but it’s not as drastic as what some people thought.”
Some others studying this site include professor of science and associate dean of research Samuel Bentley, associate professor of oceanography and coastal sciences Kehui (Kevin) Xu, University of Southern Mississippi professor of geology and geography Andy Reese and Beth Middleton from the U.S. Geological Survey.
“It looks [like] the trees all died at the same time, so we have this hypothesis that some type of event occurred, buried the trees very quickly and that quick burial helped preserve them through time until Hurricane Ivan uncovered them,” DeLong said.
One of the reasons that lead researchers to this hypothesis is the bark found on the centuries-old trees. Bark is one of the first things to go once a tree dies, leading them to believe in a quick burial, said DeLong.
“If you were to go out in the forest today and everybody cut down the trees, but their stumps were there, that’s what it looks like on the bottom,” DeLong said. “There’s sea anemones growing on them and crabs and just all kinds of life, there’s a turtle that lives there. It’s just all this incredible marine life and all of these stumps on the bottom.”
DeLong and others plan to return to the site in two weeks to map and film the site and identify the species of some of the trees. The team has completed two trips with LSU Coastal Studies Institute in 2015 and 2016.
“One of the things that’s kind of sad about the ancient forest is that we’ll eventually lose it,” DeLong said. “Marine organisms will deteriorate all the wood, just like a shipwreck.”
