Conservation officials in Minnesota blame the illegal introduction of a non-native pet goldfish for the massive number of dead carp found washed up on the shores of a lake in southern Minnesota.

Koi Goldfish From East Asia

The Minnesota Department of Natural Resources said that the carp died due to a virus from the koi goldfish. The same virus has also been found in at least eight other lakes in southern Minnesota in the past year.

The koi is a colored variety of Amur carp kept for decorative purposes in ponds or water. Some of their major colors are black, red, orange, white, yellow, blue, and cream.

This fish has been raised in East Asia for centuries. The species, however, is apparently damaging to habitats in other parts of the world as authorities said that a large number of carp found dead in the lake is linked to a virus from koi.

Koi Herpes Virus

Findings from the Department of Natural Resources Minnesota Aquatic Invasive Research Center laboratories showed that the fishes died from infection with the koi herpes virus, which only infects common carp and koi. Investigations started after dead fish started to show up on Lake Byllesby near Cannon Falls.

The DNR said that the pathogen affects the skin and gills of the fish but it cannot be transferred to humans or other animals. The agency added that releasing pet or ornamental fish into the wild is illegal.

Dangers Of Introducing New Species To An Ecosystem

The incident shows the dangers of introducing species to a new ecosystem. Invasive species can disrupt the balance in an ecosystem, such that they can alter the environment in a manner that is more in favor of them but less favorable to native species.

In some instances, the transplanted animal or plant may not thrive in its new environment. A wrong climate and lack of proper food sources, for instance, can shorten the lifespan of animals.

The Goldfish, which are native to East Asia, are considered as among the worst invasive aquatic species in the world. They can enter river systems when they are thrown from aquariums. Eradicating them can prove to be difficult once their population becomes established in the wild.

These invasive fish may disturb the habitat, affect water quality, compete with native species, and just like in the case of in Minnesota, bring about new diseases that can kill the native species.