Identifying the Appropriate Unit of Managment for GRSM Brook Trout (Salvelinus fontinalis)

King, Tim; Switzer, John; Moore, Stephen; Kulp, Matt

Great Smoky Mountains National Park (GRSM) is committed to monitoring ecological and evolutionary functions and processes of park ecosystems. Brook trout (Salvelinus fontinalis) is the only salmonid native to the Southern Appalachians and functions as a keystone species in some headwater streams. The historic use of hatchery-reared brook trout for supplemental and restorative stocking in GRSM underscores the need to recognize the evolutionary relationship among stream populations. A recent survey of microsatellite DNA variation in GRSM brook trout indicated the presence of highly significant differentiation at all hierarical levels which suggests that the individual stream should be considered the unit of management. Given that management resources are limited and that stream-specific management is often not practical, fisheries managers need to know whether the genetic divergence observed among GRSM brook trout reflect adaptive differences or is the variation due to stochastic processes like random genetic drift. DNA microarrays are a powerful method for the global analysis of steady-state intracellular mRNA levels, and thus identifying genes that are transcriptionally modulated as a consequence of metabolic or bioenergetic demands. The information gathered from these arrays of gene sequences can be used to characterize complex biological processes and interactions providing insight into the adaptive significance of observed genetic differentiation. This research objective, if funded, would represent the first attempt at determining whether GRSM fisheries managers should focus their resources on genetic relatedness or demographics.