BATON ROUGE, La. (AP) — LSU’s researchers are part of a new documentary, “The Underwater Forest,” which details the discovery and exploration of an ancient cypress forest found 60 feet underwater in the Gulf of Mexico off the coast of Alabama.

LSU Department of Geography & Anthropology Associate Professor Kristine DeLong is one of the featured scientists in the film by Ben Raines. In it, she dives the underwater forest, helps excavate it and analyzes samples of the wood and ancient pollen to find out how old the forest is.

Experts say the forest dates back to an ice age about 60,000 years ago, when sea levels were about 400 feet lower than today.

LSU marine geologists and students deployed sonar to map the forest and a coastal profiler to collect sediment cores in search of more clues.

The documentary, produced by This is Alabama and the Alabama Coastal Foundation, will be posted Sunday on www.thisisalabama.org . It will air on Alabama Public Television on Saturday at 8 p.m.