It seems that goldfish have invaded a Colorado lake in Boulder, Colorado and experts believe that the cause is the disposal of unwanted family pets.

In what likely began as a simple handful of unwanted goldfish being tossed into the lake, after years of reproducing the school now numbers between 3,000 and 4,000. The exotic species were first discovered on March 13 by the Boulder Open Space Rangers in Teller Lake #5, and experts believe that they will likely have to be removed in order to maintain the integrity of the lake.

"These are domestic fish actually.These are fish from a store I imagine. They can out-compete the native fish" CPW spokeswoman, Jennifer Churchill says. They may need to drain the lake to remove the goldfish or using electro fishing, where they stun the fish and remove the invasive species.

"Goldfish are not a native species and are very harmful to the local aquatic ecosystem," district wildlife manager for Boulder, Kristin Cannon says. "We strongly encourage the public not to dump their unwanted pet fish in our waters. It is bad for our environment, as well as illegal."

This isn't the first time pet fish have had to be removed from lakes in Boulder. In November 2012, the removal of koi goldfish from Thunderbird Lake highlighted the threat posed to the lake environments by the introduction of exotic species to the region. In this case, elecro fishing caught 2.275 nonnative goldfish that had likely been reproducing and flourishing for two to three years. What began as a drop off for unwanted goldfish pets, grew into a huge problem placing the ecosystem of the lake in danger.

"Most people don't realize the far-reaching effects of introducing exotic species to the environment," senior aquatic biologist for CPW, Ken Kehmeier says. "Nonnative species can be devastating to native populations by causing disease outbreaks and creating competition unbalance. It's an issue that anyone concerned with our environment should know about."

Unfortunately for the fish, they won't get a second chance to live as pets. Most of the fish will likely end up as food at a raptor rehabilitation program. Some residents have contacted park officials requesting to visit the lake to retrieve some of the fish to take home, but so far all of these requests have been denied by officials.

Discarding any unwanted pet, even a fish, should never be done without trying to find a proper home for the animal. In the end, you could harm the animal, or such as in this case, you could do much more harm to the environment than you could imagine.