While most visitors to Great Smoky Mountains National Park have probably heard about the black bears that roam the park, few have heard about the water bears.
Known formally as tardigrades, water bears are microscopic, eight-legged creatures that exist in sediments and soils. Though they occur nearly everywhere on earth, few scientists have bothered to study the species.
That has left the field wide open for Paul Bartels, a biology professor at Warren Wilson College. Bartels and his students have discovered 78 species of tardigrades in the Smokies, including 18 new to science.
The effort to document where the water bears roam is part of the All Taxa Biodiversity Inventory, or ATBI, a project started in 1998 that is seeking to document all living creatures in Great Smoky Mountains National Park. It is the largest natural history survey ever undertaken in the United States.
"The whole purpose of the ATBI is that somebody needs to say what's really there," Bartels said. "Somebody's got to stop to do it, and if no one does it, it will never get done. We're doing it for the tartigrades in the park."
While scientists estimate there are 100,000 unique species in the Smokies, old park records documented only 9,551 species, according to Becky Nichols, an entomologist at the park who has been involved in the ATBI.
Nichols said the diversity of trees, plants, soils, climate and other factors create diverse habitats that have given rise to many species.
"We knew there had to be a lot more than that," she said. "That was really the beginning, the impetus behind ATBI."
Since it started, the ATBI has documented 16,570 species in the park, including 6,129 species new to the Smokies and 890 species new to science. More than 1,000 scientists have been involved in the project, with more than 200 permits issued each year to researchers.
Most of these discoveries have been small or microscopic species like Bartel's water bears.
Though most of the public is oblivious to these organisms, Bartels said there is much they can teach scientists about how ecosystems work and how changes to the environment will affect the creatures.
"We are managing the park based on a subset of big things, but we don't have a clue about what happens with the microscopic things, and the bulk of the biodiversity is microscopic," Bartels said. "We are asking the tardigrades, what can you teach us about the microscopic world?"
While some groups, like beetles, butterflies and moths, are close to being fully documented, scientists are still a long way from completing the ATBI, a feat that may never be accomplished, Nichols said.
"You could keep something like this going forever and not find every living thing," she said.
Bartels said the project also faces the difficulty of convincing the public about its usefulness. While the project has inspired other inventories around the country, he said the general public has yet to be convinced of the importance of biodiversity, which is in rapid decline.
"Unless people believe that it's beneficial to find these spiky little things out there for finding a base of diversity, it won't happen," Bartels said of completing inventories like the ATBI.
"I am already seeing support for a baseline inventory start to wane. A lot of people want to start them; the question is whether people want to finish them."