Patterns of ancestry and genetic diversity in reintroduced populations of the slimy sculpin: implications for conservation

Abstract

Reintroductions are a common approach for preserving intraspecific biodiversity in fragmented landscapes. However, they may exacerbate the reduction in genetic diversity initially caused by population fragmentation because the effective population size of reintroduced populations is often smaller and reintroduced populations also tend to be more geographically isolated than native populations. Mixing genetically divergent sources for reintroduction purposes is a practice intended to increase genetic diversity. We documented the outcome of reintroductions from three mixed sources on the ancestral composition and genetic variation of a North American fish, the slimy sculpin (Cottus cognatus). We used microsatellite markers to evaluate allelic richness and heterozygosity in the reintroduced populations relative to computer simulated expectations. Sculpins in reintroduced populations exhibited higher levels of heterozygosity and allelic richness than any single source, but only slightly higher than the single most genetically diverse source population.Simulations intended to mimic an ideal scenario for maximizing genetic variation in the reintroduced populations also predicted increases, but they were only moderately greater than the most variable source population. We found that a single source contributed more than the other two sources at most reintroduction sites. We urge caution when choosing whether to mix source populations in reintroduction programs. Genetic characteristics of candidate source populations should be evaluated prior to reintroduction if feasible. When combined with knowledge of the degree of genetic distinction among sources, simulations may allow the genetic diversity benefits of mixing populations to be weighed against the risks of outbreeding depression in reintroduced and nearby populations.

The use of microsatellite loci for accurate hybrid detection in a recent contact zone between an endangered and a recently-arrived hummingbird

“…Individuals with q n values less than the threshold remain unassigned. Testing over a wide range of q n values was additionally useful to compare our results with that in published literature, as past studies have used a wide range of minimum q n values (see, for example, Gomes et al 2009;Colliard et al 2010;Coscia et al 2010;Hird et al 2010;Huff et al 2010;Neaves et al 2010). We conducted 10 independent runs using the newly generated genotypes for the three hybrid categories for each run (i.e.…”

Lack of genetic population structure of slimy sculpin in a large, fragmented lake

“…Our findings indicate that although slimy sculpin in Lake Champlain and Lake Ontario have comparable genetic diversity to slimy and mottled sculpin in streams and rivers (Huff, Miller, & Vondracek, 2010;Lamphere & Blum, 2012), they exhibit little to no within-lake genetic structure even across numerous barriers and distances up to 227 km (Breen et al, 2009;Lamphere & Blum, 2012). The lack of any observed genetic structure indicates that sculpins in Lake Champlain and Lake…”

Factors Affecting Postrelease Survival of Coded‐Wire‐Tagged Lake Trout in Lake Michigan at Four Historical Spawning Locations

“…Alternatively, given limited resources and local adaptations, reproductive efforts may be more efficient if a single genetically diverse strain is stocked (Laikre ; Huff et al. , ).…”