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Among the countries of the world, the United States has the most species of mammals and among the richest flora of any temperate country.  It leads the rest of the world in diversity of salamanders, crayfishes, freshwater turtles, and freshwater mollusks, and the southeast is the global epicenter of this aquatic diversity.  Tennessee is considered by scientists to be the most species rich inland state, with its biodiversity concentrated in the world's five most threatened types of plants and animals--fish, crayfish, mussels, amphibians, and flowering plants.  However, 22% of the state's fish species are at risk.  The loss of animals that depend on clean water for their survival sounds a warning bell for the human community.   

"Recent biological surveys of the Duck River indicate that it is one of the most biodiverse rivers in North America, according to the Tennessee Chapter of The Nature Conservancy.  Free flowing for most of its 269 miles and brimming with species, the Duck River is one of the last rivers of its kind anywhere in the nation" (Biological Surveys, The Nature Conservancy).  It has been noted in The Nature Conservancy's "Rivers of Life" as the number two aquatic hot spot in the country with 33 at-risk fish and mussel species.  Few rivers anywhere can equal the biological riches of the Duck River, and few opportunities exist to protect such a wide array of southeastern fauna.  The 1.8 million acre Duck River watershed is faced with a number of challenges, making conserving it a monumental and compelling endeavor.  These challenges range from explosive growth and municipal impacts to nonpoint source pollution from a wide array of sources.  To preserve this region, it is crucial that local communities take an active role in addressing the diverse pressures and issues affecting this remarkable system.  These pressures and topics include regional water supply issues, changing land use due to rapid and often unplanned growth, impacts of urban storm water, education and outreach, agricultural impacts, community access to the river and source water protection.

More than 75% of all molluscan species in the southeastern United States are in decline.  Molluscs are the most imperiled large animal group on the planet.  The Duck River system is one of the last refugia remaining in Tennessee, and perhaps the world, for many species.  Five of six federally listed mussels, and three listed fish species are present.  

"The Nature Conservancy's Project Manager Leslie Colley, through a grant from the Tennessee Environmental Endowment, has worked with the Tennessee Aquarium Research Institute (TNARI) and the U.S. Geological Survey (USGS) to conduct an extensive biological survey of the mussel and snail fauna of the Duck River over a three-year period" (Biological Surveys, The Nature Conservancy).  See the chart below for statistics outlining the Duck River's biodiversity.

"In 1991, the Tennessee Valley Authority (TVA) implemented the Reservoir Release Improvements (RRI) program at Normandy Dam.  The RRI program was designed to deal with water quality problems common to dam tailwaters.  TVA placed over two miles of soaker hoses in the pool of Normandy Dam to oxygenate the water before it was released from the reservoir.  Additionally, seasonal adjustments in discharge levels were made to shift more water back into the river during the spring and summer seasons.  In 1999, The Nature Conservancy opened an office in Columbia to support conservation efforts in the Duck River watershed, and TVA removed the last physical vestiges of Columbia Dam.  In 2001, TVA donated lands acquired for the dam project to the Tennessee Wildlife Resources Agency (TWRA).  

"With all recovery elements in place, the last element needed was time.  Ten years after TVA initiated the RRI program, a new mollusk inventory of the basin was commissioned by The Nature Conservancy and TWRA to determine how well this most sensitive fauna had responded to recovery efforts.  Scientists from the USGS and the TNARI were contacted to lead the survey project.  Now nearing completion, this study has shown a remarkable turnaround in the molluscan resources of the Duck River.  Mussel densities have increased between two to six fold since 1988, and the range and numbers of endangered species have increased exponentially.  Mussel diversity was greatest in the town of Columbia where 33 species of freshwater mussels now reside in an area that was too toxic for most of these species a generation ago.  Additionally, a small fish survey of the lower Duck River found 97 species of fish residing in a half-mile section of river.  

With the mollusk fauna already gone or rapidly disappearing from most southeastern rivers, the Duck River stands in

stark contrast to the degradation in the region" (Return of the Natives, 2004).

"Recently, the Sheepnose mussel was found in the Duck River--the first recorded finding for that mussel in 100 years.  According to Paul Johnson, research scientist with the Tennessee Aquarium Research Institute, the comeback of the mussels and snails in the Duck River region is 'one of the most important conservation stories in the United States'" (Biological Surveys, The Nature Conservancy).  

"The upper Duck River Utility has also assisted recovery efforts through extensive planning of water needs in the basin.  Based upon extensive flow modeling, the utility has estimated they can meet water supply needs in the basin for the next 50 years" (Return of the Natives, 2004).

References

Biological Surveys Find Duck River Most Biodiverse in U.S.  The Nature Conservancy.  Aug. 22, 2003.  Last available from the World Wide Web <http://nature.org/wherewework/northamerica/states/tennessee/press/press1167.html>.

Return of the Natives:  Community Guide for Restoration of Fish & Aquatic Species.  Southeast Watershed Forum. January 1, 2004.  Last available from the World Wide Web <http://www.southeastwaterforum.org/pdf/newsletters/Return_of_Natives.pdf>.