After Recent Routine Monitoring, Invasive Zebra Mussels Were Not Detected in Braunig and Calaveras Lakes

Written by:

Posted on:




Get The Latest:

Join our print or digital newsletter to be informed about the agency’s many projects and other news.

New report shows zero detection of Zebra Mussels found in local waterways

SAN ANTONIO – The San Antonio River Authority (River Authority) recently received results from routine Zebra Mussel monitoring conducted in November 2021 at Calaveras and Braunig Lakes. No juveniles were detected, and environmental DNA (eDNA) analysis was negative. This data comes from a collaborative effort between the River Authority, CPS Energy, and Texas Parks and Wildlife to monitor both Braunig and Calaveras Lakes for the presence or absence of zebra mussels.

Zebra mussels multiply rapidly and are easily carried to other waterways by boats and equipment. The mussel’s few natural predators in Texas waterways have little effect on their spread. Infested streams and lakes have reported colonies of zebra mussels taking over habitats and nutrients from native fish and freshwater mussel colonies. They can also interfere with recreation and wreak financial havoc on infrastructure. The River Authority’s Aquatic Biologists continue to monitor the San Antonio River for zebra mussel detections.

Transporting zebra mussels, among other prohibited invasive species, is illegal in the State of Texas. TPWD and River Authority require both motorized and non-motorized boat recreationalists to do the following:

1. Clean your watercraft, anchor, trailer, and gear. Remove any plants, animals, or foreign objects.

2. Drain all water from your watercraft and completely empty your bait buckets to rid them of possible microscopic zebra mussels and larvae.

3. Dry everything for a week or more before entering another water body. If unable to dry it completely, wash it with high-pressure, hot (140° F), soapy water.

The public is also encouraged to help stop the spread of zebra mussels by reporting sightings to both the River Authority and TPWD. To do so, contact the River Authority’s Environmental Investigations team online or by calling 866-345-7272, and TPWD reporting system found on their Stop Invasives webpage. The public may also get more information on zebra mussel sightings from the Nonindigenous Aquatic Species (NAS) website. NAS is an information resource for the United States Geological Survey and provides scientific reports, online/realtime queries, spatial data sets, regional contact lists, and general information.

For further information, visit the Public Services section at to learn more about our Environmental Investigations team and look for our Education section to learn more about the San Antonio River Watershed

Related Articles


Stem Density Efforts

Stem Density efforts are still in place but will not directly affect any parks or trails. We apologize for any inconvenience.

San Pedro Creek Culture Park – STREAM

Due to maintenance, the water features for STREAM art piece will be turned off until further notice. The STREAM Microphone area is also closed due to vandalism. We apologize for the inconvenience.

River Reach Newsletter Signup

River Reach is offering an electronic delivery of the quarterly newsletter in order to be more environmentally conscious. Please fill out the form below and indicate your preferred method of delivery.

By submitting this form, you are consenting to receive marketing emails from: San Antonio River Authority, 100 East Guenther St., San Antonio, TX, 78204, US. You can revoke your consent to receive emails at any time by using the SafeUnsubscribe® link, found at the bottom of every email. Emails are serviced by Constant Contact. This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.