‘Monster’ goldfish have long prowled Lake Tahoe, scientists say

Reports of giant goldfish wreaking havoc in Lake Tahoe may have garnered fresh attention this week, but officials say the feral fish are just part of an army of invasive critters that they’ve been battling for years.

Searching for invasive species that have colonized the resort-town lake, researchers Sudeep Chandra and Christine Ngai at the University of Nevada, Reno, nabbed the monstrous fish in 2011. One of them, part of a school of about 15 fish, stretched 14 inches and tipped the scales at 4.2 pounds -- dwarfing its typically finger-length, aquarium-bound counterparts.

Chandra, speaking Thursday from a conference in New Orleans discussing aquatic invasive species, described the goldfish’s effect on the ecosystem. The animals prey on fish that are native to Tahoe waters – and, the limnologist added, “they also excrete nutrients that are kind of in the ratio of Miracle Gro.”

That chemical-rich waste triggers algal blooms that sully the lake’s once-crystal-clear waters, Chandra explained.

Researchers think the goldfish ended up in Lake Tahoe as a result of aquarium-dumping, allowing the aquatic pets to run wild and multiply.

“Please do not dump your goldfish into Lake Tahoe!” a USDA Forest Service page warns, adding that “goldfish are among the most destructive non-indigenous species in North America.”

Goldfish are just part of the problem. Several species, including largemouth bass, crappie and bluegill, have been part of what the service calls the “warm-water fish invasion.”

A 2010 bulletin from the University of Nevada, Reno, and UC Davis gave the mug shots of some of the main offenders, warning people around Tahoe that dumping such alien fish into Lake Tahoe is illegal.

The battle against these invaders is not new, officials said.

“There have been pilot projects for removal going on for several years,” said Jeff Cowen, spokesman for the Tahoe Regional Planning Agency.

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