Conservation Genetics

, Volume 11, Issue 3, pp 935–949 | Cite as

Spatial patterns of hybridization between bull trout, Salvelinus confluentus, and brook trout, Salvelinus fontinalis in an Oregon stream network

  • Patrick W. DeHaan
  • Lawrence T. Schwabe
  • William R. Ardren
Research article


Hybridization with introduced species represents a serious threat to the persistence of many native fish populations. Brook trout (Salvelinus fontinalis) have been introduced extensively throughout the native range of bull trout (S. confluentus) and hybridization has been documented in several systems where they co-exist and is seen as a significant threat to the persistence of bull trout populations. We identified a group of diagnostic microsatellite loci to differentiate bull trout and brook trout and then used these loci to examine the spatial distribution of hybrids in the Malheur River basin, Oregon USA. In random samples of approximately 100 fish from each of three creeks we identified 181 brook trout, 112 bull trout and 14 hybrids. Although bull trout, brook trout and hybrids were found in all three creeks, they were not evenly distributed; brook trout were primarily found in the lower sections of the creeks, bull trout further upstream, and hybrids in the areas of the greatest overlap. One creek with a population of brook trout in a headwater lake provided an exception to this pattern; brook trout were found distributed throughout the creek downstream of the lake. Several post-F1 hybrids were identified suggesting that hybrids are reproducing in the Malher River Basin. Mitochondrial DNA analysis indicated that both female bull trout and brook trout are involved in hybridization events. Analysis of population structure suggested that brook trout have established multiple spawning populations within the Malheur system. Data presented in this study suggest that relative abundance of brook trout and habitat quality are important factors to consider when evaluating the threat of hybridization to bull trout populations.


Hybridization Bull trout Brook trout Introgression Salvelinus 

Supplementary material

10592_2009_9937_MOESM1_ESM.doc (78 kb)
Supplementary material I (DOC 79 kb)


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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Patrick W. DeHaan
    • 1
  • Lawrence T. Schwabe
    • 2
    • 3
  • William R. Ardren
    • 1
    • 4
  1. 1.U.S. Fish and Wildlife Service, Abernathy Fish Technology CenterLongviewUSA
  2. 2.Burns Paiute TribeBurnsUSA
  3. 3.The Confederated Tribes of Grand Ronde, Natural Resources DivisionGrand RondeUSA
  4. 4.U.S. Fish and Wildlife ServiceEssex JunctionUSA

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