On March 16, 2021, the Texas Parks and Wildlife Department (TPWD) designated Medina Lake as “positive” with the invasive species, Zebra Mussels. The first sighting in Medina Lake was on February 11, 2021, by a member of the community who contacted TPWD for verification. Shortly after this, TPWD conducted their own searches and located at least 1 more Zebra Mussel. BCRAGD also conducted a search on February 24, 2021, locating a single Zebra Mussel.