In California, the Department of Fish and Game has found a better way to deal with introduced freshwater fish than poisoning entire bodies of water...they're blowing the fish up!! The northern pike (Esox lucius) introduced to Lake Davis are aggressive predators, and have taken over the lake. After a previous attempt at poisoning the fish affected water quality, caused health problems, and prevented all fishing for months, Fish and Game has turned to a less toxic option. Explosions are set off underwater and dead fish are then scooped off the surface. If the detonations turn out to significantly harm the trout that also inhabit the lake, officials will look into other management options.
Though this method is obviously one of control rather than eradication, it makes sense in this situation. Since the pike were reintroduced intentionally after the lake was cleared the first time, it is likely introductions will continue to occur. Northern pike is a popular game fish, and though it has been introduced by humans to many lakes, its range is considered circumarboreal. You can read more about the effects of northern pike introduction in this .pdf file. (Thanks to a member of the ALIENS-L listserver for posting the link to this story.)