Scientists urge awareness after non-native fish found in Tahoe creek

INCLINE VILLAGE, Nev. — Lucas McNamara was hiking around Griff Creek in Kings Beach last week with his family when he saw a black, spiny fish, about 1 foot long, lying dead in the creek.

“Dad, you need to look at the big crazy fish,” the 7-year-old yelled as he ran up the bed of the creek next to the North Tahoe Fire Protection District fire station.

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 on July 3 the UC Davis Tahoe Environmental Research Center in Incline Village, where the McNamaras life part time.

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, and Allen presumed someone made a 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.”

Allen is out of the country currently, so the fish won’t be dissected for another couple weeks. Once it is, scientists will examine its stomach to see what it was eating before it died.

Abnormally large goldfish found in recent years in the Tahoe Keys were most likely the result of private citizen’s dumping their unwanted pets, according to TERC.

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 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, Wittmann said.

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.

Heather Segale is Education and Outreach Director for the UC Davis Tahoe Environmental Research Center. She may be reached at hmsegale@ucdavis.edu. Bonanza/Sierra Sun Editor Kevin MacMillan contributed to this report.