Premium
Assessing the Conservation Value of Hybridized Cutthroat Trout Populations in the Quinn River Drainage, Nevada
Author(s) -
Peacock Mary M.,
Kirchoff Veronica
Publication year - 2004
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/03-017
Subject(s) - population , subspecies , introgression , oncorhynchus , endangered species , ecology , geography , rainbow trout , trout , threatened species , fishery , biology , habitat , sociology , fish <actinopterygii> , demography
The Lahontan cutthroat trout Oncorhynchus clarki henshawi , an interior basin salmonid, is endemic to the hydrographic Lahontan Basin, which encompasses parts of northern Nevada, northeastern California, and southeastern Oregon. This subspecies is currently listed as threatened under the 1975 U.S. Endangered Species Act. Landscape‐ and population‐level research suggests that this subspecies has survived in a desert environment by living in large, interconnected stream and/or stream‐and‐lake systems that support a metapopulation dynamic. Threats to the subspecies include habitat fragmentation as well as competition and hybridization with nonnative salmonids. Hybridization with the closely related rainbow trout O. mykiss compromises rangewide recovery efforts by increasing the risk of introgression and subsequent loss of pure populations in restored population networks. Here we use a suite of highly variable genetic markers (microsatellites, simple sequence repeats, and arbitrarily amplified regions) to assess levels of hybridization between Lahontan cutthroat trout and rainbow trout in the McDermitt Creek stream system located in the northwestern Lahontan Basin. The McDermitt Creek stream system is the only potentially networked stream system in the Quinn River/Black Rock Desert distinct population segment (DPS). Three populations (Sage Creek, Line Canyon Creek, and Indian Creek) targeted for reconnection were assessed for hybridization status. The Line Canyon Creek population was the only pure Lahontan cutthroat trout population. The Sage Creek and Indian Creek populations had varying levels of introgression. Fixation index ( F ST ) results showed significant genetic differentiation among Quinn River, Humboldt River, and Western Basin DPS populations (pairwise F ST estimates ≥ 0.3, P = 0.00064). Due to the limited number of pure populations in the Quinn River/Black Rock Desert DPS and their genetic distinctiveness, preservation of the populations is warranted, despite limited introgression.