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Small mussels - big problem

A small invasive species is making its way into Texas’ waterways, and you have the power to stop it. Zebra mussels are one of the most problematic aquatic invasive species in the state. So how do these 1-2 inch creatures with a striped shell wreak such havoc on our waterways and infrastructure and what are they exactly?

Zebra Mussels
Photo credit of Texas Parks and Wildlife

Zebra mussels are small, but they reproduce in an enormously big way, and can reach extremely high densities of up to 700,000 mussels per square yard. In Texas, they only live for 1-2 years, but grow rapidly and can reproduce within their first year. Each year, a mature female zebra mussel may release up to one million eggs, while the male may release more than two hundred million sperm into the water where fertilization takes place. Larvae are microscopic and free-floating in the water for weeks until they settle and attach onto something. Settled mussels will attach to virtually any hard surface, including plants, other mussels, and boats. When they attach to something mobile like a boat or into the water inside a recreational watercraft, they hitch a ride and can be unintentionally transported to water in other lakes or waterways.

The result of this species in a waterway can be substantial. Aside from zebra mussels easily attaching to and damaging boats and hurting aquatic life, they also pose a threat to infrastructure. They may cling to and clog pipes which can affect the water supply and/or control of power generation facilitates that use surface water. They also have the potential to litter shorelines with sharp shells that can harm both wildlife and people. Once they take hold, getting rid of these tiny mussels is costly and extremely difficult. The best course of action is to prevent them from ever becoming a problem.

Besides CPS Energy managing both Braunig and Calaveras lakes as a recreational area for our community to enjoy, these lakes also provide cooling water for equipment at nearby power plants. While there has been no detection of zebra mussels in either  Braunig and Calaveras lakes, nearby Medina Lake has recently tested positive for the species. This confirmed case increases the likelihood of the species spreading easily to the San Antonio River and potentially into Braunig and Calaveras. To stop this from happening,Texas Parks and Wildlife’s “Clean, Drain and Dry” campaign asks boaters to properly clean, drain and dry their boats before moving to another lake. Signs encouraging the cleaning of boats are posted near the boat ramps at both Braunig and Calaveras lakes.

Invasive Species Warning sign

Currently, 31 lakes and rivers in Texas are positive for zebra mussels. CPS Energy remains committed to our pillar of Environmental Responsibility by continuously working with the Texas Parks and Wildlife Department to monitor for early detection of invasive species in our lakes. The San Antonio River Authority collects water samples twice-a-year from Braunig and Calaveras Lakes which are then sent to Texas Parks and Wildlife Department for microscopic analysis.

With Earth Day happening this month, CPS Energy encourages park goers and boaters alike to remain vigilant in keeping this invasive species out of our unaffected waterways. With all of us working together, we can protect our ecosystem and keep our lakes a place of relaxation and recreation. Remember – small mussels can cause big problems!