Mozambique Tilapia have been introduced into Texas for aquatic vegetation control, I believe initially in private ponds and lakes. Supposed to die once water reaches 50 degrees, but they are likely a little more cold hardy than that. The private lake I live on once intentionally introduced Tilapia for vegetation control and the fish were billed to die every winter and not breed therefore requiring reintroducing annually. In reality, most winters few if any tilapia die and they are rapid breeders. Prior to a cold outbreak in the winter of 2017-2018 their numbers in our lake had skyrocketed and were causing a big decline in the native fish, especially bluegills/sunfish types, but even largemouth bass. That winter’s extra cold temperatures wiped out thousands of tilapia and the bluegill have mostly recovered, but the tilapia numbers were on a steady rise too This winter’s cold killed a good number of tilapia in the lake, but not all of them. Tilapia aren’t much for taking lures or flies. Bigger ones will sometimes eat nymph patterns or woolly buggers. I don’t like them and wished tilapia never got introduced.
But, a much more significant fish kill due to the recent record cold happened along the Texas Coast. Looks pretty grim as videos and pictures continue to roll in of stacks of dead trophy speckled trout littering shorelines along with and among so many other species. Looks to be at the worst along the middle and lower coasts where waters tend to be shallow and cool quickly dooming fish that cannot tolerate water in the 30s or even the low 40s for long. Numbers of fish lost and assessments are still be tabulated, but likely millions of fish have died, with speckled trout being hit the hardest among the most popular and sought after texas saltwater gamefish.
Texas has had these massive cold water kills in the past, the worst in my lifetime happened in 1983 and 1989. TP&W took measures then to change limits and such to help the fish recover and will likely do so soon once they get a handle on the extent of the situation.