A monster size goldfish has been found in the depths of Lake Tahoe. Biologists worry how this 1.5 foot long and 4.2 pound visitor may affect the lake.

Reno biologist Sudeep Chandra of the University of Nevada said goldfish inhabited the water of the Tahoe Keys since 1990s. However wasn't until 2011, such "giant" goldfish have been found in the lake and more were found since.

"During these surveys, we've found a nice corner where there's about 15 other goldfish," she told LiveScience. "It's an indication that they were schooling and spawning."

However the giant goldfish is not naturally found in the lake and considered invasive species, which will hurt the Lake Tahoe's ecosystem.

Although it's unclear how the goldfish are introduced to Lake Tahoe, researchers believe the goldfish may have been dumped them by aquarium owners, who are unaware of the negative harm that nonnative species can have.

"What we forget is this introduction can have a large impact in the region," Chandra said.

"The invasion is resulting in the consumption of native species," Chandra said. What's more, the invasive fish excrete nutrients that cause algal blooms, which may pollute Tahoe's clear waters.

Aquarium dumping has become an increasing problem and taking a toll on native species, according to Sue Williams, an ecology professor at UC Davis.

"Globally, the aquarium trade has contributed a third of the world's worst aquatic and invasive species," Williams said.

Biologists at University of Nevada said it will conduct a research in May to understand the extent of goldfish population in Tahoe.