An article by:

Casey Phillips

Release date:

08/04/17

7:32 am

The Tennessee River: Superhighway Through an ‘Underwater Rainforest’

For scientists, biodiversity is a critical measurement of an ecosystem’s ecological richness. The higher the biodiversity, the more plant and animal species that can be found in a particular location.

According to a 2016 study created through a partnership between the Tennessee Aquarium Conservation Institute (TNACI) and the University of Georgia River Basin Center (RBC), the Southeast is a hotbed of aquatic biodiversity, a region with a variety of freshwater wildlife that is practically unparalleled in the temperate world. Some conservationists have likened it to “an underwater rainforest.”

This “heat map” of biodiversity was produced through a partnership between the Tennessee Aquarium and the University of Georgia River Basin Center. Analyzing the distribution of fishes, mussels and crayfish across almost 300 watersheds in 11 states. Warmer colors indicate watersheds with higher diversity of life and greater need of conservation work. (Credit: Tennessee Aquarium Conservation Institute/University of Georgia River Basin Center)

And winding its way through the center of this treasure trove of biodiversity? The Tennessee River — all 652 miles of it. In that sense then, Dr. Andreas Fath’s TenneSwim project is a suitably one-of-a-kind study of a one-of-a-kind ecosystem.

The TNACI/RBC study evaluated the distribution of more than 1,000 fish, crayfish and mussel species in almost 300 watersheds across 11 states. According to the report’s findings, the region of the Southeast with the greatest biodiversity is a bullseye centered on Middle and Southeast Tennessee, Northwest Georgia and Northern Alabama.

A crayfish recovered from the Hiwassee River. Branching off from the Tennessee River northeast of Chattanooga, the Hiwassee is part of the Tenenssee River system, which runs through one of regions of highest biodiversity in the temperate world. (Credit: Casey Phillips/Tennessee Aquarium)

The Tennessee and Cumberland river drainages, which were considered as a single region in the study, contained more species (231 fish, 125 mussels, 65 crayfish) than any other region the researchers analyzed. Of the top 10 watersheds considered to be priority areas for conservation work by the study’s creators, 40 percent were in the Tennessee River basin.

As he swims the Tennessee River, Dr. Fath is tracing a course that runs through the heart of one of the most ecologically rich and significant aquatic ecosystems in the world.

A Bronze Darter (Percina palmaris) emerges from a substrate of leaves at the Tennessee Aquarium. Tennessee is home to more than half of the 200 darter species found in North America, and many of them are endemic (found only in) the Tennessee River system. (Credit: Casey Phillips/Tennessee Aquarium)

And hand in hand with the Tennessee River’s tremendous abundance of wildlife is a rogue’s gallery of threats that imperil that diversity, from habitat loss to degraded water quality due to storm water runoff. As Dr. Fath proceeds along his route, his analysis of the waterway, particularly looking at concentrations of chemicals such as pharmaceuticals, heavy metals and fertilizers, will help conservationists to better understand what imperils this unrivaled ecosystem and to plan courses of action to preserve it.

A Warpaint Shiner (Luxilus coccogenis) recovered in the Hiwassee River, which feeds into the Tennessee River. Like all fish, this species relies on clean water, making waterway analyses like TenneSwim of tremendous value to conservationists working to ensure its survival. (Credit: Casey Phillips/Tennessee Aquarium)

In light of the potential for TenneSwim to set a world record and the sheer difficulty of swimming the entirety of the Tennessee River, it might be easy to lose sight of the project’s equally noteworthy scientific aims. By comprehensively analyzing the waterway, Dr. Fath and his team will be providing an unprecedented collection of data that will help ensure one of the world’s hotspots of biodiversity isn’t allowed to cool.

TenneSwim