The Texas Parks and Wildlife Department (TPWD) has upgraded Richland Chambers Reservoir southeast of Dallas to fully “infested” with invasive zebra mussels. Fully infested status signifies that there is an established, reproducing population in the lake. The status change is a result of recent sampling efforts that revealed new evidence of reproducing and growing populations of zebra mussels in the lake.
Zebra mussels were discovered for the first time in 2017 when the Tarrant Regional Water District located several adults on multiple occasions in a single cove near the dam. This resulted in a zebra mussel “positive” designation for Richland Chambers at the time. The Tarrant Regional Water District responded by conducting a localized treatment in the cove, using a novel low-dose copper compound, in an effort to eradicate the mussels.
Sampling efforts did not detect any zebra mussels in 2018 or 2019 but in 2020 Tarrant Regional Water District and TPWD staff found zebra mussels at two locations near the cove where they were found in 2017 and at the Kingswood boat ramp approximately two miles upstream. The discovery at the new boat ramp location provided evidence that the mussels have begun to spread in the lake. In addition, multiple size classes were found, which indicates a reproducing population in the reservoir.
“Conditions in most Texas lakes are highly conducive to zebra mussel establishment. Once they are introduced to a water body, it’s only a matter of time before they fully infest the lake and have negative impacts which is why it is so important for all boaters to take steps to clean, drain, and dry their boats to prevent the spread,” says Monica McGarrity, TPWD Senior Scientist for Aquatic Invasive Species Management.
Earlier in the summer, TPWD elevated Grapevine Lake and O.H. Ivie Lake to fully infested status after field surveys found more mussels of different sizes. However, TPWD and partners monitor more than 40 lakes for early detection of zebra mussels and no additional detections of the invasive species or their larvae in other lakes have been identified in 2020. Additional sampling will be conducted this fall and biologists hope to find no new introductions.
Currently, zebra mussels are found in 30 Texas reservoirs across five river basins as well as in river reaches downstream of infested lakes. These invaders can litter shorelines with sharp shells, impact recreation, harm aquatic life, damage boats and clog water intakes.
“Although zebra mussels are now found in 30 Texas lakes, there are still many, many other lakes they haven’t invaded. Taking a few minutes at the ramp to remove plants, mud and debris from your boat and drain all the water and then opening up compartments once you get home and allowing the boat and gear to dry completely can make a big difference in preventing the spread of zebra mussels as well as other invasive species,” advises Brian Van Zee, TPWD Inland Fisheries Regional Director.
If you have stored your boat in the water at a lake with zebra mussels, it is likely infested with zebra mussels and poses an extremely high risk for moving this invasive species to a new lake. Before moving your boat to another lake, call TPWD at (512) 389-4848 for guidance on decontamination. A status map and list of these lakes can be found at tpwd.texas.gov/zebramussels.
The transport of aquatic invasive species can result in legal trouble for boaters or transporters. Transporting prohibited invasive species in Texas is illegal and punishable with a fine of up to $500 per violation. Boaters are also required to drain all water from their boat and onboard receptacles, including bait buckets, before leaving or approaching a body of fresh water.
For more information on how to properly clean, drain and dry boats and equipment, visit the TPWD YouTube channel for a short instructional video. To learn more about zebra mussels and other invasive species in Texas, visit tpwd.texas.gov/StopInvasives. Information for marinas and owners of boats stored in the water on lakes with zebra mussels can be found on the TPWD website.
TPWD and partners monitor for zebra mussels in Texas lakes, but anyone who finds them in lakes where they haven’t been found before should report them by emailing photos and location information to aquaticinvasives@tpwd.texas.gov to help identify new introductions. Anyone who spots them on boats, trailers or equipment that is being moved should immediately report the sighting to TPWD at (512) 389-4848.