Media Contact: TPWD News, firstname.lastname@example.org,
Zebra Mussels Discovered in Canyon Lake
AUSTIN — Invasive zebra mussels have now
been positively identified in the Guadalupe
River Basin in what is
now the state’s southernmost affected lake.
and Wildlife Department (TPWD) fisheries biologists and game wardens confirmed
the presence of zebra mussels at Canyon Lake June
8. Employees at Canyon
noticed the zebra mussels while working on a boat that had been stored in a
slip at Crane’s Mill Marina and contacted TPWD to report the discovery
and to get verification.
“This is the first
positive documentation of zebra mussels in Canyon
Lake and in the Guadalupe River Basin,”
said Brian Van Zee, Inland Fisheries regional director for TPWD.
“Although marina staff have intercepted several incoming boats over the
years that had invasive mussels attached, it is essential that boats stored on
infested lakes be decontaminated before they’re moved as they are a key
pathway for spreading this invasive species.”
The rapidly reproducing zebra
mussels, originally from Eurasia, can have serious economic, environmental and
recreational impacts on Texas
reservoirs and rivers. Zebra mussels can cover shoreline rocks and litter
beaches with treacherously sharp shells, clog public-water intakes, and damage
boats and motors left in infested waters.
unfortunate not only for the reservoir but also for downstream resources
– including the Guadalupe
River and the reservoirs
downstream from Canyon Dam,” said Van Zee.
is an 8,230-acre U.S. Army Corps of Engineers reservoir on the Guadalupe River,
located 30 miles north of San Antonio and 40
miles southwest of Austin.
The Guadalupe River
and all of the reservoirs downstream of Canyon
Lake are now at risk of invasion as
zebra mussel larvae disperse downstream, including Lake
Lake Placid, Meadow Lake, Lake Gonzales (H-4), and Lake Wood
state-listed threatened freshwater mussels found in the Guadalupe River basin
could now be negatively impacted, including the Texas Pimpleback,
the Golden Orb and the Texas Fatmucket.
documented in other parts of the country is that zebra mussels can colonize on
the shells of native mussels, and reach a density where they essentially
smother and suffocate the native mussels,” Van Zee said.
Since zebra mussels were first
found in Texas in 2009, 10 lakes in four river basins are now classified as
infested, meaning they have an established, reproducing population –
Belton, Bridgeport, Dean Gilbert (a 45-acre Community Fishing Lake in Sherman),
Eagle Mountain, Lewisville, Randell, Ray Roberts, Stillhouse Hollow, Texoma and now
Van Zee said that the
lake’s popularity as a boating destination for Texans around the state
combined with its deep water and suitable habitat made it vulnerable to the
spread of zebra mussels.
“Unfortunately, I think
this is a textbook scenario of a zebra mussel infestation that is the result of
a contaminated boat being launched in the lake,” Van Zee said. “It
really hits home how important it is for boaters to take ownership of the
problem and to take the appropriate steps before moving a boat with zebra
mussels attached as well as to clean, drain and dry their boats every time they
leave a lake. We know that Texans love their lakes and rivers and by taking
these three simple steps they do a lot of good toward helping prevent further
spread of invasive species in our state.”
In Texas, it is unlawful to possess or
transport zebra mussels, dead or alive. Boaters are required to drain all water
from their boat and onboard receptacles before leaving or approaching a body of
fresh water in order to prevent the transfer of zebra mussels that might be
inside. Zebra mussel larvae are microscopic and both adults and larvae can
survive for days in or on boats transported from a lake. The requirement to
drain applies to all types and sizes of boats whether powered or not: personal
watercraft, sailboats, kayaks/canoes or any other vessel used on public waters.
In addition to the adults and
juveniles found in the lake, plankton samples collected from Canyon Lake
also found zebra mussel larvae at multiple sites, meaning the lake has a fully
established infestation. TPWD is working with the U.S. Army Corps of Engineers
as well as the Guadalupe Blanco River Authority to continue to assess the
extent of the infestation on Canyon
Boater awareness and education
is very important when it comes to the issue of invasive species and TPWD will
continue working with its partners across the state to spread the word to
More information about zebra
mussels can be found online at tpwd.texas.gov/ZebraMussels.
On the Net:
Stop Zebra Mussels Video: http://youtu.be/E4Y5ILzKgHg
There is an important new emergency notification system
being established on the following Guadalupe County Emergency and Fire Marshal