**Acknowledgements**

**4.5. Management implications**

68 Biological Resources of Water

tives and thoroughly and accurately documented.

should be managed on a stream-by-stream basis.

than 5% admixture.

triploid brook trout [48].

Brook trout is the only salmonid native to the southern Appalachian region. The American Fisheries Society Southern Division Trout Committee developed a position statement [22] expressing the importance of SABT and presenting recommendations for conservation-oriented management of this regional resource. Our results contribute to the recommended completion of genetic inventory of critical populations using non-lethal sampling methods. In this context, we frame the management implications for management of SABT populations. Results from this and other studies demonstrate that stocking of non-native genotypes poses long-term genetic impacts and interferes with efforts to conserve southern Appalachian brook trout. Although negative effects of stocking have become well known, some fisheries management agencies maintain imprecise stocking records. Further, hatchery personnel often substitute one brook trout stock for another based on availability. We recommend that all stocking and transfers of brook trout be well planned with cognizance of genetic conservation objec-

Management units—that is, populations that are demographically independent of one another—may be defined functionally as populations that have substantially divergent allele frequencies at many loci [47]. We had but limited ability to estimate levels of genetic diversity and differentiation among regional brook trout populations using allozyme markers. The results of ongoing screening of microsatellite DNA markers will be used to quantify differentiation among native populations, providing the basis for defining defensible management units. Results to date support the view that southern Appalachian brook trout populations

Those populations characterized as pure SABT should be given conservation priority. The stocking and transfer of non-native genotypes into these populations should be prohibited. Harvest should be allowed only in those populations that are demographically able to sustain themselves. We recommend that introgressed populations that contain less than 5% admixture from northern-strain brook trout be treated as 'pure' southern. However, we caution that the level of introgression in these populations may be higher than allozyme frequencies suggest; hence, individuals from these streams should not be transferred into streams that contain pure SABT populations. Hatchery brook trout should be stocked only into those streams that contain pure northern-strain populations and those with greater

We caution that any negative consequences of stocking also would apply to native northernstrain populations (i.e., in the James and Roanoke river drainages). Allozyme markers do not provide enough resolution to differentiate between native northern and hatchery populations, and so we recommend that all brook trout populations should be screened and characterized using microsatellite or single nucleotide polymorphism markers. Until we know more about the genetic composition of these populations, it may be wise to stock only infertile

Southern Appalachian brook trout hatchery stocks are being established in conservationoriented hatchery programs ([49], https://brooktrouthatchery.wordpress.com/, http://archive. This work was funded through the Federal Aid in Sport Fish Restoration Project F-128-R, administered by the Virginia Department of Game and Inland Fisheries, and is based on the Master's degree research of Joanne (Davis) Printz. We thank George Palmer and Cliff Kirk for assistance with fieldwork and collection of genetic samples. Ray Morgan of the Maryland Department of Natural Resources kindly provided unpublished data from Maryland populations, and Doug Besler of the NCWRC generously provided tissue samples. Finally, we thank Chris Printz of ATS International, Inc. of Christiansburg, VA for his assistance in the design and production of the maps. Funding for EH's participation in this work was provided in part by the Virginia Agricultural Experiment Station and the Hatch Program of the National Institute of Food and Agriculture, U.S. Department of Agriculture.
