Monster goldfish found in Lake Tahoe

Gigantic goldfish, like this one held by University of Nevada, Reno, researcher Christine Ngai, have been found in the waters of Lake Tahoe / Heather Segale

A new kind of lake monster has been found, in the depths of Lake Tahoe: gigantic goldfish. Researchers trawling the lake for invasive fish species scooped up a goldfish that was nearly 1.5 feet long and 4.2 pounds.

"During these surveys, we've found a nice corner where there's about 15 other goldfish," environmental scientist Sudeep Chandra of the University of Nevada, Reno, told LiveScience. "It's an indication that they were schooling and spawning." The arrival of the fish, which were probably dumped there by aquarium owners, has Chandra worried -- goldfish are an invasive species that could interfere with Lake Tahoe's ecosystem.

It's unclear whether the giant fish were introduced as fully grown adults, or while they were still small, Chandra said. But even a small creature can have a big impact, if there are enough of them.

The goldfish are just one of several species of invasive warm-water fishes in Lake Tahoe. "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 threaten to muddy Tahoe's clear waters. [Photos: Giant Goldfish & Other Freaky Fish]

Fish out of water

Aquarium dumping has become a common practice in the United States and elsewhere, and it's taking a toll on native wildlife. A recent report on California's aquarium trade found that fish owners and importers are introducing hardy, nonnative aquatic species to California waters. "Globally, the aquarium trade has contributed a third of the world's worst aquatic and invasive species," Sue Williams, who was lead author of the report, told OurAmazingPlanet, a sister site of LiveScience, in January.

While the exact number of aquarium owners dumping fish is unknown, scientists know the practice is occurring because these species could not have ended up in these waters naturally. Between 20 percent and 69 percent of fish keepers surveyed in Texas admitted to dumping, according to Williams.

Other ways that invasive species find their way into natural ecosystems include aquaculture, live seafood, live bait, and fishing and recreation vessels. More than 11 million nonnative marine organisms representing at least 102 species arrive at ports in San Francisco and Los Angeles alone, Williams has found.

The invaders include tropical fish, seaweed and snails. One of the nastiest is a deadly type of seaweed known as Caulerpa. A type of algae that produces toxic compounds that kill off fish, Caulerpa was eradicated in 2000 (at great expense) from lagoons in Southern California.

Aquarium owners should be more careful when disposing of unwanted fish and other animals, Williams cautioned. "It's pretty simple: Don't dump your fish," she said. Instead, she suggests calling the pet shop that sold the fish or your state department of fish and wildlife. (Euthanasia is another option, but simply flushing fish down the toilet can be problematic -- for the fish and for your plumbing.)

So why do people dump fish? Studies of dumping have shown that size and aggressiveness of the fish are two main factors, Williams said.

The largest pet goldfish, according to the BBC, was a fish named Goldie that was 15 inches long and weighed more than 2 pounds.

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[AdinaSobo]

For whatever it's worth, if there is a sick or injured fish in the tank, it can be euthanized by placing it in a container (plastic bags work well) with some water and placing it gently in the freezer. I used this method successfully on some fish that were lingering after someone put dish detergent into a classroom tank. The fish lost consciousness quickly (they're exotherms) and died painlessly. For larger fish, I understand that clove oil is recommended. Either way, don't flush them.

Also, I've never had a fish I couldn't trade in to the place I bought it if it outgrew the tank, and over the last 40 years in multiple states and even more cities, that's a lot of different fish stores!

[vista8635]

PBS Fish Commercial: Be More Empowered

http://www.youtube.com/watch?v=SKEf-Sc6ytQ

[oldoc44]

Hey! That's maybe MY fish!! Spent summers at Lake Tahoe as a kid and recall pouring out my goldfish bowl before we closed the cabin for the winter; couldn't bring it back home and wouldn't "flush" him. Glad he's alive and well, - or is he??

[Orlando__]

Isn't that Barry Bond's goldfish?

[alpinequeen]

Twice a year, I'd cull my pond and give the excess goldfish to the local pet store and they'd sell them as pond raised gold fish. This past Summer, a seagull stopped by for lunch and nearly cleaned the pond out.

[superdem1]

Many aquarium hobbiests are kind-hearted people who cannot bring themselves to cull their tanks, they let the populations explode beyond tank capacity, and they think they are being merciful by "setting free" their excess fish. They are not thinking that they are actually releasing non-native species and causing big problems. We now have a snakehead problem in the eastern wild waters, this was a tank-kept species and even a food fish in oriental restaurants, but it is now a reproducing invader with no natural enemies, which is eating all the native fishes and frogs.

[sierrarenderings]

JD2408: Perhaps those are some of the goldfish I've bought as feeders for my Oscars. On behalf of my oscars, thank you.

[Ellen-Degenerate]

Pure Media hype.
I thought the gold fish was going to beat least 6ft long.
Yawn!

[windstar68]

Thats nothing! I've seen goldfish 2 to 3 foot in legth in a lake in Great Falls va.

[Jonseen]

I think Carp and Goldfish are two different things. We see Carp in amusement parks ponds, etc. But THAT is a real Goldfish! I agree with the article, it's a whopper!

I looked it up online and goldfish are related to the many species of carp and koi. But they are a distinctive group in their own right.

[HobartSchmenge]

The headline said MONSTER GOLDFISH, but I'm feeling kind of let down, or even duped after seeing the photo. I guess my definition of "monster" is different.

[varigdc10]

Sometime ago I heard there's a dam somewhere in the South, maybe Kentucky or Arkansas that has huge catfish by a dam in real deep waters at the bottom. A car plunged into the water from the roadway on the dam, when divers went down to the car they saw huge 20 feet long catfish that can swallow people. Beware of the deep waters, remember The Creature From The Black Lagoon?

[maciverj]

Lake Hodges near Escondido California has had stories about monster sized catfish from diver sent to do exams on the dam after every earthquake of a nominal size. Then we have the Lake Hodges monster too... so I think anywhere with deep water will have these stories lol

[DickVanstone]

Lake Hartwell on the SC and GA border has rumored catfish the size of VW Bugs near the dam. Sitting in relative darkness with it's mouth agape eating whatever flows into it.