Non-native aquarium fish found at Lake Tahoe

Lucas McNamara, 7, was hiking around Griff Creek near Kings Beach Fire Station last week with his family when he saw a black, spiny fish, about 1-foot-long, lying dead in the creek. He ran up the creek bed, yelling, “Dad, you need to look at the big crazy fish!”

Lucas’ parents, Steve and Jen McNamara, decided to make this a teachable moment for their son, who already shows active interest in science and the environment.

“I told Lucas that this fish is not normal for Lake Tahoe and may be harmful to the other fish and animals in the lake,” Steve said.

They brought the fish to the UC Davis Tahoe Environmental Research Center in Incline Village.

UC Davis TERC fish biologist Brant Allen recognized the fish as a Plecostomus, or common algae-eating aquarium fish. These fish can grow too large for their tanks. Allen presumed someone made the bad decision to release the non-native fish into the wild.

“This prehistoric-looking, tropical fish may have died because it couldn’t survive the cold creek temperatures or didn’t have enough accessible food,” Allen said. “Either way, it highlights the continued lack of understanding of aquarium dumping at Lake Tahoe.”

Goldfish found in the Tahoe Keys were most likely the result of private citizen’s dumping their unwanted pets. The goldfish were able to find mates, spawn, and have babies in the lake. Some of the goldfish caught in Lake Tahoe had grown to between 7 and 15 inches in length, and approximately 0.3 to 4 pounds in weight.

Other non-native warmwater species such as largemouth bass, bluegill and crappies have also gotten a foothold in the lake and are competing with native fishes and changing the food web in ways that are still being investigated. University of Nevada, Reno and California Department of Fish and Wildlife researchers have removed over 50,000 fish (weighing 7,000 pounds) from the Tahoe Keys through mechanical removal electroshocking projects in an attempt to reduce the harmful impact on the native fish populations.

“One of the most powerful tools in keeping Lake Tahoe beautiful is the connection between people using the lake and scientists trying to understand what may be impacting it,” said UNR researcher Marion Wittmann. She commended the McNamara family for taking the extra step to inform scientists of unknown organisms found in or near the lake. An organism like this tropical fish that does not belong here could potentially impact the lake’s health.

Citizen monitoring gives scientists quick notice about problems before they can become greater problems.

“I think it's exciting to show my son and others the importance of protecting our environment,” Steve McNamara said.

This past holiday weekend had a huge number of people visiting the Lake Tahoe region. There was also a high amount of careless behavior, including littering, vandalism, dangerous fireworks and non-native species transport. Volunteer beach clean-up events organized by the League to Save Lake Tahoe indicated that 2,260 pounds of trash were picked up from five sites around the lake.

Thankfully, there were also a large number of caring volunteers and citizens who had their boats inspected for invasive species, cleaned up the beaches, picked up trash, and did their part to protect the environment at Lake Tahoe.

For more information, visit the UC Davis Tahoe Science Center in Incline Village at www.TahoeScienceCenter.org or go here.

Inspectors intercept 23 contaminated boats bound for Lake Tahoe
Watercraft are the largest transporters of aquatic invasive species (AIS), and the boat inspection program is critical to preventing the spread of AIS into Lake Tahoe and the surrounding water bodies.

A new invasive species infestation in Lake Tahoe could have devastating impacts. Invasive species multiply quickly and can colonize on all underwater objects including docs, water pipes, filtration systems, piers, ramps, and boats. They destroy fish habitat, impair boat engines and negatively impact water quality and recreation.

This season alone, inspectors have intercepted and decontaminated 23 boats containing invasive species bound for the waters of Lake Tahoe. Some of these boats contained invasive quagga mussels, and some were carrying unidentified snail species. Without natural predators, these invasive species pose serious threats to the ecology, recreation and local economies of the Lake Tahoe Basin.