The Texas Parks and Wildlife Department reports that freshwater mussels are one of the most at-risk types of animal in all of the U.S., and six more species have reached critically low population numbers in Texas.
After an August proposal by the U.S. Fish and Wildlife Service, six species of Texas freshwater mussels will be protected under the Endangered Species Act (ESA). They are the Texas pimpleback, Guadalupe orb, Texas fatmucket, Guadalupe fatmucket, false spike and Texas fawnsfoot. The first five are listed as endangered, and Texas fawnsfoot is considered threatened.
The proposal is not locally controversial as Texas cases often are, said University of Texas at Austin biology professor Sahotra Sarkar. Rather, Sarkar is concerned about how much difference it will make.
“We would be a lot more sanguine if they had been listed at least a decade ago when listing was first proposed by conservation scientists,” Sarkar told Interior Newswire.
WildEarth Guardians, a conservation nonprofit organization, filed petitions to list the species under the ESA 14 years ago, according to the Center for Biological Diversity. It further reported that the Fish and Wildlife Service, despite agreeing that the species needed protection, did not heed the organization’s petitions citing “higher priority actions” at stake. Earlier this year the center filed suit against the federal agency for failing to protect 10 freshwater mussel species, including three of the five currently listed as endangered.
Despite their tiny and even aversive appearance, freshwater mussels are among the freshwater aquatic invertebrates that are crucial actors in their ecosystems. They’re also among the most imperiled taxonomic groups in North America and across the globe.
“[Freshwater mussels] play major ecosystem roles but, even independent of these roles, they are among the most fascinating components of biodiversity,” Sarkar said. “They also play sentinel roles. When freshwater species are in trouble, we know that we have severe problems with water quality.”
What is harming this animal to such a degree? Sarkar said it primarily comes down to overconsumption, pollution and invasive species.
“There are two major causes for the problems of freshwater aquatic invertebrates in Texas," he said. "The disappearance of adequate water quantities in streams and aquifers, largely a result of consumption and pollution, largely a result of uncontrolled economic and industrial overgrowth. There is also a problem of invasive species but that is less true here than in many other regions of the country.”
The Center for Biological Diversity added that the mussels are also battling the consequences of humans diverting rivers and streams or relying on the watersheds for development. These changes disrupt water currents and cause sediment changes in the mussels’ habitats.
"One of the key impacts on these mussel species is river flow,” Myron Hess, an environmental lawyer in Austin, told the Houston Chronicle. “If the river stops flowing or dries up, the mussels are not going to survive. They’ll be more vulnerable to predators without the protection of water, and without a strong flow, pollution in the river could build up and adversely affect them.”
The Fish and Wildlife Service will designate hundreds of miles of watershed along the Guadalupe, Colorado, San Saba, Llano, Brazos and Trinity rivers as well as many others as protected critical habitat for these six species, amounting to 1,944 miles of river flow combined. Under this protection, any other federal agencies planning to commit an act that would destroy or harm the designated areas must consult with the service.
Texas, Sarkar said, needs to start treating its water with respect, and “use it sustainably so as to not condemn future generations to miserable lives bereft of the natural beauty that still surrounds us.” He called for the stop of “unregulated and unsustainable economic overgrowth fueled by overconsumption,” which causes land-use land-cover (LULC) change and threatens biodiversity.
“We must return to living as we traditionally have in this state, with wonderful stewardship of our resources compared to most of our neighboring states,” Sakar added. “In the case of these species, relatively small stretches of rivers have been identified as their critical habitat. It should not be difficult to maintain these in a condition that allows the mussels to exist.”
The Guadalupe River Basin is home to a variety of endangered and threatened species, and the Guadalupe-Blanco River Authority intends to develop a conservation plan to ensure that both animals and people that depend on a clear and reliable water supply are not left wanting in years to come, the Houston Chronicle reported.
“Central Texas is blessed with abundant life-giving streams and rivers, but unbridled development has put these freshwater bottom-feeders at high risk of extinction,” said Michael Robinson at the Center for Biological Diversity. “Protecting unique mussel species will help preserve clean, flowing water for other creatures and people as well.”
Designating a river as a critical habitat does not mean that people can no longer enjoy the waterway recreationally or even utilize it commercially.
“It simply means we have to be careful not to hurt water quality too much in everyday use, something we should be paying attention to on all our rivers and streams, all of the time,” Sarkar said.
The federal agency has one year after its proposal to finalize the listings, which is expected to happen early in 2022. The service accepted public comment through October.
Sarkar, and many others, he said, are frustrated that action has taken this long and that modern climate change activists have “derailed a wider, more diverse and more radical environmental agenda.”
“Environmentalists used to pay attention to this global problem, but the necessary focus on it has disappeared of late because of the unfortunate infatuation with climate change, which also has the same cause [as threats to biodiversity],” Sarkar said.
Some ecosystems are too late to save. For example, in the Balcones Canyonlands of central Texas, widespread pouring of concrete and paving for developments made the land impermeable, preventing water flow and drying up an aquifer, destroying an ecosystem filled with micro-endemic species.
“Those like me, who have spent our entire lives worrying about the disappearance of biodiversity, are worried that continued focus on carbon trading and offsets and the like is taking us away from the protection of endangered habitats from irreversible transformation,” Sarkar said.
The Texas Parks and Wildlife Department encourages concerned people to get involved by reporting all incidental observations of freshwater mussels and getting familiar with mussel biology and handling regulations.
