Giant goldfish are breeding in Lake Tahoe.
The remarkable-sized fish are turning up in the lake near the California-Nevada border.
Because of Lake Tahoe’s importance to local tourism, a team of biologists patrols the lake, taking samples and measuring the fish population. The team is looking for invasive species, such as largemouth bass. The biologists examine and count the fish by using an electric probe to stun them, and then collect them in a net.
“You can get 200 fish in one scoop,” researcher Christine Ngai told KCRA Sacramento. But Ngai found something strange in her net. “You just see this bright golden orange thing starting to float up, and you’re like, what is that? Then you take your net and scoop it up, and it’s like, it’s a goldfish.”
These are not normal, fishbowl-sized goldfish, either. Some of the fish found were almost a foot and a half in length. The fish are becoming increasingly common. Ngai says that she and her colleagues caught 15 goldfish in one day in a small section of the lake.
How did the household pets make it into the lake? There are a number of possible explanations: KCRA points to well-meaning pet owners freeing their fish by releasing them into the lake. Goldfish are also sometimes used as cheap bait, so the fish could be wiggling free or being released by fisherman emptying their bait buckets.
When presented with a food source, a goldfish won’t stop eating of its own accord. This means that goldfish with unlimited food grow as large as their environment will allow. And in a lake as large as Lake Tahoe, the goldfish can get really big.
At the moment, goldfish do not pose as much of a risk to the lake’s ecosystem as do the non-native largemouthed bass, which currently outnumber the goldfish 100 to one. But invasive species can cause massive damage to aquatic ecosystems, so the goldfish are being watched.
