Energy and Environment Reporting for Texas

Why Texas Water Planners Worry about Mussels

Texas Parks and Wildlife

Volunteers count mussels in Lake Arrowhead State Park in North Texas

You may have had mussels steamed in a bit of white wine and butter. But they most likely weren’t mussels from rivers or creeks in Texas.

“Their favorite food is bacteria. They are filter-feeders, the vacuum cleaners of the river systems,” said Marsha May, a biologist with the Texas Parks and Wildlife Department.

“They’re taking in all kinds of things that can be found in streams and rivers. And so they could be toxic,” cautioned May.

Not exactly appetizing. And maybe worse is what it says about the state of those Texas waterways.

“(Mussels) are an organism we consider a biological indicator of the health of the system,” said May.”Once the mussels start going, other organisms are going to follow.”

Some studies have indicated the population of native Texas freshwater mussels has been declining, so much that five species are now on a list of candidates for designation under the Federal Endangered Species Act.

Dave Fehling/StateImpact Texas

Non-native Asian clam shells are easy to find along the Brazos River. Harder to find are Texas mussels, below right

Under an agreement that came last year after a wildlife advocacy group, WildEarth Guardians, sued the Federal Department of Interior, the U.S. Fish and Wildlife Service is now gathering data to determine just how many mussels there are in Texas.

That is a worry for Texas water officials.

“If mussels get listed as endangered, it’s going to make it much more difficult to develop water supplies in Texas. It may make it more difficult to build reservoirs, for example,” said Robert Mace, Deputy Executive Administrator with the Texas Water Development Board.

The Texas fawnsfoot mussel, a candidate for the endangered species list

Efforts to protect endangered species can lead to costly lawsuits when wildlife advocates challenge the use of river water. Those advocates often argue that depleting the flow by diverting water to farms and cities upsets the delicate balance needed for river creatures to thrive.  The state and river authorities typically counter that the impact is minimal.

Bill West, the General Manager of the Guadalupe-Blanco River Authority in Seguin, said legal challenges could threaten the state’s ability to meet the demand for water.

“It has some major, potential impacts on the economic future of the State of Texas,” West said.

One such potential impact is 25 miles west of Houston. Near the town of Wallis in Austin County, the City of Houston has long-range plans to divert millions of gallons of water from the Brazos River into a reservoir it would build on some 9500 acres of what is now farm and ranch land. Two species of native mussels are known to inhabit this stretch of  the Brazos.

Dave Fehling/StateImpact Texas

Site for future reservoir in Austin County near Brazos River

“The identification of an endangered species in the area could have some effect on the building of the reservoir, ” wrote Judi Pierce with the Brazos River Authority in an email to StateImpact.

“Much depends on the type of species, where the species ranks on the endangered list, the location and the habitat of that species and how that species would be affected in that specific location by the building of the reservoir,” wrote Pierce.

In other words, a lot of ifs. Much will depend on the assessment by the U.S Fish and Wildlife Service. A decision could come in 2016 as to whether Texas mussels are so scarce as to warrant making them an endangered species.


  • Cris Sleightholm

    Here we go again….the livelihoods of human beings versus the livelihoods of a lesser creature. Perhaps when the planet can no longer sustain life will the environmentalists lament over saving the remaining humans versus one last single mussel.

    • Opihi Man

       The issue is not humans vs. so-called “lesser creatures”. Humans waste water all over the place: washing cars unnecessarily, maintaining green lawns and golf courses in areas where green grass almost never grows naturally, decorative fountains, all sorts of other unnecessary uses, literally and metaphorically pissing our water away. When organisms like freshwater mussels, cave salamanders, fish and so on become rare enough to need federal protection to save the last few, that is a message that we humans are using the water up faster than natural processes can replenish it. By curtailing our water use in time to save the last few remaining mussels and other freshwater animals, we are also cutting back before the water shortage becomes truly life-threatening to humans. In other countries in Africa and Asia, where rare plant and animal species have little or no protection, humans have already grown past what their water supplies can support, and people are dying…

      • Cris Sleightholm

        I really don’t think the peoples of Africa, India, Australian outback, drought stricken China or the extreme drought conditions that are pervasive to the southwest  give a rats ____ about threatened lesser creatures in their dwindling to non existent water supply. The disappearance of lesser species is not uppermost on their minds as they walk up to 8 hours (in Africa) or more a day to draw water from the only well in miles where water quality is questionable. The preservation of these lesser creatures will not impact the cleanliness of rivers and streams, which are beyond help in the first place, nor will it replenish our diminishing supplies of water due to drought and other natural weather fluctuations beyond our control. 

        I agree with you regarding the absurd waste of our precious waters which is due to the lack of regulation in the interest of personal gain, esthetics, hypocritical concern, etc.What we humans should do is stop the so called “permitted” dumping of toxins into our waters so that what is left of our waters is potable, so that we don’t worry about the disappearance of our species that die off due to mutations, poison,become sterile and die off due to toxic conditions. Regardless, when it boils right down to who/what survives on the last drops of water, it will not be the mussel.

  • John

    Makes me wonder if the State will have take into consideration the economic impact on losing Texas’s fish and wildlife populations. There is another side to this story…

  • CH

    There is nothing sustainable or healthy about diverting a river. The mussels are doing their job cleaning the river for free. We can not afford to think it is OK to destroy another functioning system all for the purpose of unsustainable growth that will lead to disasters later. Such stupidity harms humans and only gives a small, temporary boost to any local economy that then has to be followed by a costly ugly mess trying to sustain something that should not have been and no one will be able to afford to fix it.  Who pays?

  • Ronnie Cundieff

    I live on Lake Jacksonville in East Texas, and it’was interesting during the drought to watch the “mussel line”  retreat down the shore.  I’m not sure what kind they are (about 1 inch in diametor)  but there are millions of them, and in the wake of the drought, we now have a “mussel shoals” extending 20+ feet down from the shoreline from their shells.  The bass love gathering up into their nests.

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