During the week of Nov. 4, biologists with the Oregon Department of Fish and Wildlife will be surveying 18 miles of McDermitt Creek looking for and removing non-native rainbow and brook trout – part of an eight year effort to restore native Lahontan cutthroat trout to this remote watershed in southeast Oregon.
This will not be the first time ODFW has taken aim at non-native trout in McDermitt Creek, said Shannon Hurn, district fish biologist in Hines. Between 2006 and 2009 biologists methodically treated the creek with rotenone, a plant-based fish toxicant, in order to remove non-native rainbow trout, brown trout and brook trout. The agency’s goal is to restore the native population of Lahontan cutthroat trout that has been pushed out by brown and brook trout or genetically comprised by hybridizing with rainbow trout.
According to Hurn, the restoration effort was complicated this spring when it appears someone illegally released rainbow and brook trout back into McDermitt Creek. The fish were discovered in late summer when biologists were preparing to re-introduce about 70 native Lahontan cutthroat trout into the creek.
Hurn said the illegal release may have been an effort to re-create fishing opportunity in the creek.
“The creek was closed to all fishing after the Holloway Fire in 2012 and our plan was to re-open fishing once the Lahontan trout population was viable,” she said. “Perhaps someone got tired of waiting.”
Biologists will conduct blood, genetic and scale tests on the rainbow and brook trout removed from McDermitt Creek to try to find out how old the fish are and whether they are from a hatchery stock. It is illegal in Oregon to transport and release live fish without a permit.
The discovery of the non-native trout will slow recovery efforts in the creek, as well as the possibility of any future fishery, Hurn added.
In the meantime, the Lahontan cutthroat trout destined for McDermitt Creek were released into nearby Sage Creek in September to help boost the population there. Biologists hope to borrow from the Sage Creek population for the McDermitt Creek re-introduction.
The trout that went into Sage Creek were from a Nevada population that was restored in the 1980s using Lahontan cutthroat trout from McDermitt Creek.
Lahontan cutthroat trout can grow to be the largest of all cutthroat trout and were once found throughout desert basins in parts of California, Nevada and southeast Oregon. In recent decades, many populations have disappeared due to dam construction, habitat loss and the introduction of non-native brown, brook and rainbow trout.
The species has been protected since 1973 and is currently listed as threatened under the federal Endangered Species Act. In 2006, it was identified in the Oregon Conservation Strategy as a species in need of conservation.
Image courtesy Oregon Department of Fish and Wildlife