Releasing non-native fish to native waters?

[Jakob]

I have a question concerning this topic.
This is a terrible thing to do, we all know that. Snakeheads for example have become a problem in many rivers and lakes throughout North America, as they grow fast and large, protect their offspring and are overall aggressive.

I've read tons of articles about the non-native fish terrorizing native fish. But other than aggression/fast breeding problems, I haven't heard much about bacteria and disease problems. Fish that are released into native waters could carry bacteria and diseases that could severely damage the eco system, as the fish's immune system isn't used to them. Have there been any bad cases of large scale deaths possibly caused by bacteria or diseases introduced with non-native fish?

Enlighten me, please!

 

[ehh]

usually i only ever hear of non-native fish decimating existing fish or plant populations.

 

[Wailua Boy]

Very possible...In Hawaii, some of the first fish introduced here(dojo loachs, livebearers, tilapia, etc.) brought nematodes/trematodes that were never here; now they infest our native species.

 

[MN_Rebel]

VHS was introduced to here via saltwater aquarium fishes. There have been many cases of huge numbers of dead fish that have been found. But it is difficult to determine what caused a massive fish die-off. Could be a disease, a sudden temperature change, lack of oxygen or chemical spill. But there are no case of a disease wiped out the entire native fish populations.

 

[Lepisosteus]

Yes a few years ago here in Ontario in the Trent Severn waterway there was a massive carp die off. Its believed that on the greater side of 24,000 carp died. The cause was a bacterial infection that led to a disease, the source was from what I remember a gold fish or koi carp that was released in the Peterborough area. From a marine owner prospective this was a very smelly year and not the most ideal for boating. If you are interested on this topic just search carp die off in lake Simcoe.

 

[Jakob]

Thanks for the info guys, much appreciated.