03064nas a2200169 4500008004100000022001400041245015700055210006900212300001200281490000700293520245200300100002302752700002202775700002302797700001802820856005602838 2020 eng d a0921-297300aElucidating the impact of anthropogenic supplementation, isolation and ecological heterogeneity on Brook Trout (Salvelinus fontinalis) genetic structure0 aElucidating the impact of anthropogenic supplementation isolatio a403-4200 v353 a

Context

Preservation of genetic diversity is a commonly cited, yet under-evaluated aspect of species conservation plans. Understanding the influence of human-mediated translocations and habitat constraints on landscape patterns of genetic structure in threatened fish species is essential to maintaining biodiversity and adaptive potential.

Objectives

We evaluated the degree of influence from supplemental stocking, assessed the spatial population genetic structure, and examined the potential relationship between hybridization and ecology for Brook Trout (Salvelinus fontinalis) in the Black River watershed in New York State, USA.

Methods

We used 13 microsatellite loci from over 450 fish at 18 sampling locations to map genetic structure and diversity, estimate the level of influence from stocked conspecifics, and model the relationship between hybridization and ecological characteristics.

Results

We found widespread genetic introgression attributable to state-based stocking activities and a pattern of hierarchical genetic diversity across the landscape, which has additionally been influenced by geography. Site-specific fish assemblage variables appear to be unrelated to introgressive hybridization from stocked conspecifics, and only one hydrochemical variable, SO42−, exhibited strong explanatory power in predicting hybridization between wild and supplemented fish. A single locality exhibited genetic structure consistent with no history of introgression potentially associated with differences in elevation, and thus contributed disproportionately to the level of genetic diversity observed across the landscape.

Conclusions

When examining genetic structure in fluvial riverine networks, it is important to consider the combined and interacting effects of both hybridization and habitat, which may result in augmented genetic structure not predictable from any single factor.

1 aBruce, Spencer, A.1 aGeorge, Scott, D.1 aBaldigo, Barry, P.1 aWright, J., J uhttp://link.springer.com/10.1007/s10980-019-00955-z03015nas a2200277 4500008004100000022001300041245014400054210006900198300001100267490000700278520201700285653001702302653001702319653002602336653001802362653002802380653001902408653002602427100002302453700002202476700002402498700002102522700002702543700001802570856014902588 2019 eng d a2351989400aA methodological approach to the genetic identification of native Brook Trout (Salvelinus fontinalis) populations for conservation purposes0 amethodological approach to the genetic identification of native  ae006820 v193 a

As biodiversity is transformed on a global scale, identifying and protecting populations unaffected by habitat disturbances is essential to ensuring natural genetic diversity is not irretrievably lost. Furthermore, knowledge of the interactions between endemic populations and human-introduced conspecifics is imperative to the creation of management strategies that conserve and enhance population viability. In this study, these issues were examined for Brook Trout (Salvelinus fontinalis) populations from the Northeastern United States through the characterization of the spatial genetic structure of over 2000 wild fish, collected from 83 different sampling locations, and encompassing 18 individual watersheds. Population genetic analyses of microsatellite data at 13 loci demonstrate that, despite centuries-long stocking practices, roughly half of the populations examined exhibit genetic structure consistent with native origins. In addition, when examining the populations that revealed influence from stocked con-specifics, only a limited proportion of ancestry was attributed to stocked fish in the majority of cases. The methodological approach presented in this study for identifying native populations demonstrated strong population subdivision within and among populations, watersheds, and drainage basins. These findings are consistent with past inferences regarding native population structure of cold-water fish species and represent a detailed accounting of the remaining Brook Trout populations still intact in their native waters. Furthermore, the extent of such populations greatly exceeds what had been previously identified and prioritized as ‘heritage’ based on stocking history. The methods and data presented here may serve as an important tool to inform diversity maintenance, species recovery planning, and biodiversity conservation in this and other genetically unique and historically important native species.

10aBiogeography10aconservation10aConservation genetics10aIntrogression10aLandscape heterogeneity10aNative species10aSalvelinus fontinalis1 aBruce, Spencer, A.1 aDaniel, Peter, C.1 aKrause, Maureen, K.1 aHenson, Fred, G.1 aPershyn, Carrianne, E.1 aWright, J., J uhttps://linkinghub.elsevier.com/retrieve/pii/S2351989419302574https://api.elsevier.com/content/article/PII:S2351989419302574?httpAccept=text/xml02420nas a2200241 4500008004100000022001400041245014700055210006900202300001000271490000700281520163000288653001701918653001401935653001401949653002201963653002301985653002602008100002302034700002202057700002602079700001802105856005502123 2018 eng d a1566-062100aConfirmation of a unique and genetically diverse ‘heritage’ strain of Brook Trout (Salvelinus fontinalis) in a remote Adirondack watershed0 aConfirmation of a unique and genetically diverse heritage strain a71-830 v193 a

In fisheries management, understanding anthropogenic impacts on fish population genetic structure is essential because genetic diversity is a fundamental attribute contributing to a species’ evolutionary capacity. An extended history of supplemental stocking has led to the introgression of genes from non-local, hatchery-reared brook trout (Salvalinus fontinalis) into natural Adirondack populations in the state of New York. Managers have therefore gone to great lengths to protect known or suspected pristine “heritage” populations, but the genetic integrity of most populations is unknown. We used 11 microsatellite loci to examine a putative, but as yet unconfirmed “heritage” population in Dix Pond (Essex County, New York), in an effort to confirm its genetic uniqueness, quantify genetic diversity, and determine the geographic extent of the population. No spatial population structure was found within the Dix Pond/Elk Lake watershed, with minimal signs of introgression from historical stocking. The Dix/Elk population showed allelic richness, and effective population size comparable to the highest diversity heritage population among the four that we used for comparison. These patterns support continued heritage status for the Dix Pond population and recognition of the entire Dix-Elk watershed as habitat for this strain. We conclude this study by discussing how the genetic techniques employed here may help to inform future management decisions associated with the conservation and protection of imperiled populations throughout the globe.

10aconservation10aDispersal10aFisheries10aGenetic diversity10aLandscape genetics10aSalvelinus fontinalis1 aBruce, Spencer, A.1 aHare, Matthew, P.1 aMitchell, Matthew, W.1 aWright, J., J uhttp://link.springer.com/10.1007/s10592-017-1019-602331nas a2200133 4500008004100000245016700041210006900208300001600277490000600293520181400299100002302113700001802136856004302154 2018 eng d00aEstimates of gene flow and dispersal in wild riverine Brook Trout (Salvelinus fontinalis) populations reveal ongoing migration and introgression from stocked fish0 aEstimates of gene flow and dispersal in wild riverine Brook Trou a11410-114220 v83 a

As anthropogenic impacts accelerate changes to landscapes across the globe, understanding how genetic population structure is influenced by habitat features and dispersal is key to preserving evolutionary potential at the species level. Furthermore, knowledge of these interactions is essential to identifying potential constraints on local adaptation and for the development of effective management strategies. We examined these issues in Brook Trout (Salvelinus fontinalis) populations residing in the Upper Hudson River watershed of New York State by investigating the spatial genetic structure of over 350 fish collected from 14 different sampling locations encompassing three river systems. Population genetic analyses of microsatellite data suggest that fish in the area exhibit varying degrees of introgression from nearby State‐directed supplementation activities. Levels of introgression in these populations correlate with water‐way distance to stocking sites, although genetic population structure at the level of individual tributaries as well as their larger, parent river systems is also detectable and is dictated by migration and influenced by habitat connectivity. These findings represent a significant contribution to the current literature surrounding Brook Trout migration and dispersal, especially as it relates to larger interconnected systems. This work also suggests that stocking activities may have far‐reaching consequences that are not directly limited to the immediate area where stocking occurs. The framework and data presented here may aid in the development of other local aquatic species‐focused conservation plans that incorporate molecular tools to answer complex questions regarding diversity mapping, and genetically important conservation units.

1 aBruce, Spencer, A.1 aWright, J., J uhttp://doi.wiley.com/10.1002/ece3.4556