Invaders

Invasive Quagga Mussels Arrive  in Texas

Here’s a “first” no one wants to achieve. Several invasive quagga mussel larvae were detected for the first time in Texas in 2021 at Amistad Reservoir, along the border near Del Rio. No juveniles or adults have been found to date. It’s the first invasive mussel species found in the Rio Grande basin.

Prolific quagga mussels are a close relative of the invasive zebra mussel, which has invaded 33 Texas lakes since 2009.

“This detection of invasive quagga mussels is a very unfortunate first for Texas,” says TPWD’s Monica McGarrity. “Unlike zebra mussels, quagga mussels can inhabit greater depths and can settle on soft substrates [like mud or sand] and hard surfaces [like rock or infrastructure], meaning they can colonize more of the lake.”

One microscopic quagga mussel larva was detected (and confirmed by DNA testing) at Diablo East and three more at a second site, Rough Canyon.

National Park Service staff have actively monitored Amistad Reservoir for zebra and quagga mussels since 2014, starting shoreline surveys using mussel detection dogs last year.

Quagga mussels and zebra mussels are often transported to new lakes by boats. Invasive mussels attach to boats, and their microscopic larvae are sometimes trapped and transported in residual water. The mussels can survive for days out of water, often hiding in crevices.

“Each boater cleaning and draining their boat and allowing compartments and gear to dry completely can make a big difference in protecting our Texas lakes,” says TPWD’s Brian Van Zee.

Call TPWD at (512) 389-4848 to report observations or to receive decontamination guidance. Other items stored in infested lakes (such as barges, docks, hoists and pumps) can also spread invasive species.

Transporting prohibited invasive species in Texas is illegal and punishable with a fine of up to $500 per violation. Click for more information.