Australia has a problem.  Apparently, people are disposing of their pet goldfish by dumping them in the lakes and rivers of the country and they are thriving in the wild, growing to as much as four pounds and the size of an American football, according to csmonitor.com.

And, they are not only causing problems in the area in which they were dumped by the owners.  New research has found they will travel as much as 150 miles to find a suitable place to raise their families.  And, the researchers from Murdoch University’s Centre of Fish and Fisheries say they might just be very difficult to stop.

Lead author on the new study, Stephen Beatty, said in a released statement, “Once established, self-sustaining populations of alien freshwater fishes often thrive and can spread into new regions, which is having a fundamental ecological impact and are major drivers of the decline of aquatic fauna.”

The goldfish, according to the research, can grow to match the size of is new-found habitat, and the buffet of new food and resources now within its reach.  This can  cause disruptions in the feeding habits of native fish populations, and the goldfish may even eat the eggs of its competitors in the region.

Australia isn’t the only region to experience the influx of non-native goldfish.  Likely former pets up to as long as 18 inches are causing ecological concerns in Lake Tahoe, California, and goldfish and Asian carp have become so commonplace in the Great Lakes the local fishermen are selling them to make a profit.

Major resources are needed to rid an area of any invasive species, once it has established a foothold.  One such endangered fish sanctuary in Utah, the Red Hill Desert Garden is going dry to try to kill off invasive species impacting the area, and the government of New Zealand has already invested $28 million to rid the country of non-native animals plaguing the island nation.

Most people don’t consider what may be the consequences of dumping the pet fish into the area waters.  Experts suggest you take the pet to the pet store for someone else to adopt instead of just releasing it into the wild.  You could help prevent an expensive clean-up down the road.