|Sudeep Chandra at Lake Tahoe|
The researchers believe the large mouth bass and bluegill that are typically are found in much warmer waters were introduced into Lake Tahoe by anglers about 15 years ago.
If left unchecked, scientists said, the species could threaten Lake Tahoe's cold-water fish.
"If you don't tackle them early, they just proliferate," Sudeep Chandra, an expert in freshwater sciences for University of Nevada, Reno told the Las Vegas Review Journal.
Dr Chandra has teamed up with scientists from University of California, Davis, in a programme supported by the US Forest Service and the California Department of Fish and Game, to trace the movements of 14 fish through next winter.
Bass and bluegill are thought to have been introduced by anglers in the Tahoe Keys area of South Lake Tahoe about 15 years ago and they appear to be spreading around the lake.
The fish have overrun the Keys and have been found in more than half of the marinas and lagoons sampled around the lake, the Review Journal reports.