Juro brings up an interesting point regarding regs with pet stores. When my wife and I go into a pet managerie and handle a cat or dog in a playpen, we're required to sign our names and contact info into a log in case that particular animal is found to be a vector of a certain disease. If so, we can be contacted immediately and take appropriate actions.
When someone purchases a pet (bird or mammal), there's plenty of paperwork filled out at these stores. Tracking is easy. But I'm not certain about purchasing fish, especially exotics. If the same steps are taken to track the purchase of species such as snake heads, perhaps the buyer would think twice before assuming it's OK to just heave them into the nearest body of water. The key is EDUCATION AT THE POINT OF PURCHASE.
If someone is more in tune with the tracking of exotic fish once purchased from a store, please advise. I'm wondering just how well we could track these problems down.