Conservation of population structure and genetic diversity under captive breeding of remnant coaster brook trout (Salvelinus fontinalis) populations

Abstract

Rebuilding wild populations often involves captive broodstocks derived from small, remnant populations. We measured a hatchery program's ability to conserve genetic diversity when founding captive broodstocks from such populations. Migratory coaster brook trout were extirpated from most of their historic range in US waters of Lake Superior and were proposed for listing under the Endangered Species Act. Two captive broodstocks, one with 19 founders and another with 99 founders, were established to rebuild US populations. We used microsatellite markers to examine genetic variation in source populations and early hatchery generations. Broodstocks retained the strong differentiation found between source populations; however, one founder, with a low probability of belonging to either source population, sired 5.7% of F 1 progeny. We found small changes in within-population genetic variation across successive wild and hatchery generations of broodstocks. Evaluation of stage-specific survivorship indicated that equalizing family sizes of embryos produced modest gains in the effective number of breeders, and that survival in the hatchery was nearly random across families. Our study demonstrates the value of genetic monitoring during initial stages of hatchery programs for small and declining populations.

Estimation of census and effective population sizes: the increasing usefulness of DNA-based approaches

“…For example, knowing if certain factors (mating system, fecundity, or survivorship) always lead to the same reduction in N e from N C would help researchers infer N e from N C . Another use of understanding N e /N C ratios is in predicting how management actions could increase N e or the N e /N C ratio to maintain genetic variation (Cooper et al 2009).…”

From microsatellites to single nucleotide polymorphisms for the genetic monitoring of a critically endangered sturgeon

“…The easiest way is when nonmodel species are closely related to model organisms for which a large amount of genomic information and/ or SNP chips are already available and could be "cross-amplified" (e.g., Cooper, Miller, & Kapuscinski, 2009;Haynes & Latch, 2012;Ogden, Baird, Senn, & McEwing, 2012). There are usually two main approaches aimed to discover novel SNPs, mostly depending on the availability of genomic resources.…”

The ghost of introduction past: Spatial and temporal variability in the genetic diversity of invasive smallmouth bass

“…Although our results support the notion of multiple introductions, this should be interpreted with caution as several factors may be responsible for this pattern, including an unsampled source population, postinvasion genetic drift, insufficient marker resolution and admixture in the source population (Chown et al., 2015; Gray et al., 2014). Given that hatcheries make use of artificial selection techniques to enhance species production and abundance (e.g., Aprahamian, Smith, McGinnity, McKelvey, & Taylor, 2003; Lamaze et al., 2012), it is possible that the introduced M. dolomieu were of admixed or hybrid origin, as has been reported for stockings of S. fontinalis (Cooper, Miller, & Kapuscinski, 2010; Lamaze et al., 2012; Sloss, Jennings, Franckowiak, & Pratt, 2008). …”