Hunting Hydrilla

Scientists think they've got hydrilla (Hydrilla verticillata) under control in the Rio Grande in Texas, according to this report from The Brownville Herald. The surface area covered by the invasive aquatic weed has decreased by about 50% since May 2003. The weapon of choice in this case? Grass carp (Ctenopharyngodon idella), though the scientists point out that there was likely also a benefit from heavy rainfalls that swept some of the hydrilla out to sea.