BASALT - Four years after anglers started hauling in perch from Ruedi Reservoir, a seasoned fisherman caught what he believes was a bass there Wednesday.
Marco de la Espriella said a juvenile fish, maybe 5 inches long, aggressively went after a spoon lure that was about half the fish's size. At first, he thought it was a tilapia but after reflection, he suspected that it was a bass.
"I've been fishing for 25 years, and I definitely know my fish," de la Espriella said. "I can assure you it's not a trout."
De la Espriella was fishing with his mom where the Upper Fryingpan River enters Ruedi Reservoir, on the far eastern side by Dearhamer campground. De la Espriella threw the fish back in the water. They didn't take a picture of it.
He and his mom researched freshwater fish via the Internet Thursday night and concluded that the fish he caught most likely was a smallmouth bass, based on the jawline. De la Espriella lives in Costa Rica, where he fishes extensively. He said the fish he caught at Ruedi resembles what's known as a "guapote" in Costa Rica. That fish is called a rainbow bass in the U.S., he said, though what he caught more closely resembled a smallmouth rather than a rainbow bass, based on images.
"The only reason we are not 100 percent sure that it is the smallmouth bass is because the one I caught had less stripes," de la Espriella said, referring to a picture he saw of an adult smallmouth bass. "The one I caught had only two or three vertical stripes, but that could be because it was an infant."
Kirk Webb, a fishing guide with Taylor Creek Fly Shop in Basalt, said it's plausible that someone could have illegally stocked smallmouth bass and they are surviving in the relatively warm water of the reservoir. While bass are an invasive species, he believes there is little chance they will pose a threat to the other fish in the reservoir. Colorado Parks and Wildlife stocks Ruedi with lake trout and kokanee salmon. Webb noted there are countless lakes in Minnesota and Michigan where multiple species of fish co-exist.
The bass also don't pose a threat to the gold-medal trout fishing waters of the lower Fryingpan River in Webb's estimation. The river water is too cold for the bass to reproduce, so they would die out if some got past the dam, he said.
When perch were discovered in Ruedi in August 2008, officials with the Colorado Division of Wildlife, now part of Colorado Parks and Wildlife, said the danger was the perch competing with trout for a limited food supply at the reservoir.
Neither perch nor smallmouth bass are stocked at Ruedi Reservoir, said Mike Porras, a spokesman for the agency. There are cases in Colorado where anglers have intentionally stocked waterways with an invasive species or they allowed it to happen by using bait fish. Either way, it's illegal and can result in a fine and loss of hunting and fishing privileges.
"We call those people bucket biologists, and it's not a term of endearment," Porras said. He stressed that he wasn't commenting specifically on Ruedi Reservoir. The agency hasn't detected the presence of smallmouth bass there, he said.
De la Espriella said his concern is the smallmouth will eat the more desirable lake trout, based on the aggressiveness of the small fish he caught. "Those fish will go after anything," he said.