title: Hiding in Plain Sight: A Case for Cryptic Metapopulations in Brook Trout (Salvelinus fontinalis).
abstract: A fundamental issue in the management and conservation of biodiversity is how to define a population. Spatially contiguous fish occupying a stream network have often been considered to represent a single, homogenous population. However, they may also represent multiple discrete populations, a single population with genetic isolation-by-distance, or a metapopulation. We used microsatellite DNA and a large-scale mark-recapture study to assess population structure in a spatially contiguous sample of Brook Trout (Salvelinus fontinalis), a species of conservation concern. We found evidence for limited genetic exchange across small spatial scales and in the absence of barriers to physical movement. Mark-recapture and stationary passive integrated transponder antenna records demonstrated that fish from two tributaries very seldom moved into the opposite tributary, but movements between the tributaries and mainstem were more common. Using Bayesian genetic clustering, we identified two genetic groups that exhibited significantly different growth rates over three years of study, yet survival rates were very similar. Our study highlights the importance of considering the possibility of multiple genetically distinct populations occurring within spatially contiguous habitats, and suggests the existence of a cryptic metapopulation: a spatially continuous distribution of organisms exhibiting metapopulation-like behaviors.
authors.affiliation: University of Maryland Center for Environmental Science, Appalachian Laboratory, Frostburg, Maryland, United States of America.|U.S. Geological Survey, Leetown Science Center, Aquatic Ecology Branch, Kearneysville, West Virginia, United States of America.
authors.forename: David C
authors.initials: DC
authors.lastname: Kazyak
authors.affiliation: University of Maryland Center for Environmental Science, Appalachian Laboratory, Frostburg, Maryland, United States of America.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hilderbrand
authors.affiliation: U.S. Geological Survey, Leetown Science Center, Aquatic Ecology Branch, Kearneysville, West Virginia, United States of America.
authors.forename: Tim L
authors.initials: TL
authors.lastname: King
authors.affiliation: University of Vermont, Department of Plant Biology, Burlington, Vermont, United States of America.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Keller
authors.affiliation: University of Vermont, Department of Plant Biology, Burlington, Vermont, United States of America.
authors.forename: Vikram E
authors.initials: VE
authors.lastname: Chhatre
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D016000:Cluster Analysis; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D005398:Fisheries / Q000379:methods*; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D005843:Geography; D015810:Linkage Disequilibrium; D008396:Maryland; D018895:Microsatellite Repeats / Q000235:genetics*; D011157:Population Dynamics; D045483:Rivers; D014337:Trout / Q000145:classification / Q000235:genetics* / Q000502:physiology