A freshwater ‘powerhouse’ is disappearing across the South

In Alabama’s tight knit environmental conservation and advocacy community, many are lifelong friends or neighbors. Others are family.  

“We spent our first date canoeing down Hurricane Creek in Tuscaloosa,” SELC senior attorney Sarah Stokes said while smiling across the table at her spouse of 14 years and Alabama director of The Nature Conservancy, Mitch Reid.

On being an environmentalist power couple, Reid explained, “There’s some late nights and important deadlines, and a lot of support for each other.”  

And a lot of love for their home state of Alabama.   

Reid and Stokes list stat after stat, ranking Alabama’s wildlife above internationally renowned biodiversity hubs. Mussels, turtles, snails, fish — the state’s abundance of freshwater species is unmatched. 

“Alabama’s Mobile-Tensaw River Delta is called North America’s Amazon, but really the Amazon is South America’s Mobile if you are talking about turtles,” Reid said. “But our freshwater ecosystem is like a delicate tapestry –” 

“Yes, a tapestry!” Stokes finished. “When you pull one string the rest of the picture will start to unravel.” 

Abundant mussels, resilient rivers 

If freshwater ecosystems are a tapestry, then mussels are part of the warp threads holding it together. The presence of mussels doesn’t just mean our water is healthy. Mussels actually remove pollutants from water, in Alabama and across SELC’s six-state region. 

“Mussels are a powerhouse for our rivers and streams,” explained Ramona McGee, SELC senior attorney and Wildlife Program leader. “They’re what we call a ‘bioindicator,’ which means they tell us if a body of water is healthy.”  

A small mussel can filter 12 gallons of water per day absorbing contaminants and pathogens including infectious viruses, E. coli, pesticides, and other chemicals that wastewater treatment plants may not have the ability to remove.  

Mussels are a first line of defense as the nearly 380,000 miles of streams and rivers across SELC’s six-state region adapt to climate change. Longer, hotter summers and stronger storms mean rain showers now turn into flood events. Healthy rivers and wetlands are key to prevent flooding and filter pollutants rain washes into our waterways. 

“Mussels are an incredible part of creating resilient ecosystems,” McGee said. “But the truth is they’re disappearing across the South. I don’t think we’re feeling that loss anyplace more than in Alabama’s rivers.”  

Aquatic habitats in Alabama need protection

With names like fuzzy pigtoe, southern pocketbook, and purple wartyback, it’s easy to imagine why early buttons were made from mussel shells. There are more than 180 species in Alabama, but 58 are listed as threatened or endangered under the Endangered Species Act. Many more are likely imperiled enough to warrant federal protection. 

The reason? About 5,000 miles of Alabama rivers are impaired because of years of industrial pollution and development. “But now we know what impairs our rivers. We know what can happen when we cut a forest down to build a subdivision or when we burn coal for power,” Stokes said. “Now we know what dams do.”   

Dams turn cool, flowing rivers into warm, still lakes. Less water bubbling over rocks means less oxygen in the water for wildlife — at times choking and killing hundreds of fish. Another longer-term result is a concrete or earthen barrier stopping fish, and the species that depend on them, from repopulating upstream.   

Watch the short film by our partners at Alabama Rivers Alliance.

Mature mussels hunker down on rocks below a river’s surface most of their life. Some mussels mimic small fish to lure unsuspecting larger fish so their offspring, called glochidia, can hitch a ride upstream. But dams mean fish, and the parasitic young mussels they carry, are stuck downstream.  

“We dammed the Coosa, and it was the largest single extinction event in modern human history,” Reid added. “It’s not because people wanted to go kill a bunch of mussels. They put the rivers to work, and now we know what that cost us.”  

Broken rivers

There are more than 2,200 dams across Alabama and 71 of them are regulated by the federal government. Many were built in the mid twentieth century to support navigation and hydropower, but the wildlife impacts were catastrophic.  

Before the Millers Ferry and Claiborne lock and dams were built on the Alabama River, legend has it you couldn’t jump into the water without landing on a sturgeon. Surveys between 1982 and 2002 revealed a 20-40 percent decline in the diversity of fish species, and the number of mussels species found upstream in the Cahaba River dropped from 50 to about 27. 

A river doesn’t work if you break it in pieces. Now we have a chance to reconnect Alabama.

Mitch Reid, The Nature Conservancy

Reid said there’s a bunch of “old folks” waiting below the dams.  

“They’re all 40-50 years old. They’re all the age of the dam,” Reid said, adding that those mussels are nearing the end of their lifespan. “We’re really under a time crunch. We’re going to have a literal collapse of populations.” 

Some researchers are cultivating mussels, but “that’s not a way to sustain a population,” Reid said. “That will keep that population on life support.”  

Taking down a dam can be a regulatory and political process that takes time. Time Alabama’s mussels don’t have. That is how the Alabama River fish passage project was born.  

The Nature Conservancy and other groups are working with the Mobile District of the Army Corps of Engineers to develop two natural channels of water to allow fish to swim around both the Millers Ferry and Claiborne lock and dams. These projects would reconnect the Gulf of Mexico to the Cahaba River, stretching north of Birmingham.  

“They’re building dam passages out West. There’s no reason we can’t build them here in Alabama,” Stokes said. “This could be an absolute gamechanger for waterways across the South, and should be a legislative priority.” 

There’s not a lot of policy on how the Army Corps manages conservation projects because the agency doesn’t often partner with nonprofits to build them. Reid said developing policy to support the Alabama River fish passage project could be a model for how this kind of species-saving partnership works.  

“There’s a lot of people within the Corps of Engineers, even up to the Department of Army, who are looking at this project as a way of rethinking ecosystem restoration,” Reid said. “A river doesn’t work if you break it in pieces. Now we have a chance to reconnect Alabama.”