I favor spiking the Rio Grande with piranha. LOL
In Texas, the American alligator ranges from the Sabine River
of East Texas to the Gulf of Mexico across the coastal marshes
to the Rio Grande and west to around Interstate 35, according
to the Texas Parks and Wildlife Department. The range includes
about 120 counties with the highest concentrations along the
Gulf Coastal Plains. The alligator is the only crocodilian native
to Texas, according to TPWD
https://www.lmtonline.com/news/local/article/alligator-eagle-pass-rio-grande-19472073.php