Publications by authors named "Nicholas M Sard"

Article Synopsis
  • The spread of invasive species, such as the red swamp crayfish, is linked to their reproductive success and population dynamics, making them hard to control.
  • A study developed a SNP panel to genotype 1800 individuals in southeastern Michigan, revealing important genetic information about their mating system and reproductive success.
  • Findings show a common occurrence of multiple paternity in crayfish populations, emphasizing the need for advanced genomic tools to monitor their population responses and improve control strategies.
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Reintroduction is an important tool for the recovery of imperiled species. For threatened Pacific salmonids ( spp.) species, hatchery-origin (HOR) individuals from a nearby source are often used to reestablish populations in vacant, historically occupied habitat.

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Harvest in walleye fisheries is size-selective and could influence phenotypic traits of spawners; however, contributions of individual spawners to recruitment are unknown. We used parentage analyses using single nucleotide polymorphisms to test whether parental traits were related to the probability of offspring survival in Escanaba Lake, Wisconsin. From 2017 to 2020, 1339 adults and 1138 juveniles were genotyped and 66% of the offspring were assigned to at least one parent.

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Quantifying effects of individual attributes and population demographic characteristics that affect inter- and intrasexual interactions and adult reproductive success, and the spatial and temporal contexts in which they are expressed is important to effective species management. Multi-year individual-based analyses using genetically determined parentage allowed the examination of variables associated with the reproductive success of male and female lake sturgeon () in the well-studied population in Black Lake, Michigan, USA. Spawning lake sturgeon (a total of 599 individuals where many were captured more than once based on 1024 total captures) and larvae ( = 3436) were genotyped during each of seven consecutive years (2001-2007).

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Applications of genetic-based estimates of population size are expanding, especially for species for which traditional demographic estimation methods are intractable due to the rarity of adult encounters. Estimates of breeding population size (N ) are particularly amenable to genetic-based approaches as the parameter can be estimated using pedigrees reconstructed from genetic data gathered from discrete juvenile cohorts, therefore eliminating the need to sample adults in the population. However, a critical evaluation of how genotyping and sampling effort influence bias in pedigree reconstruction, and how these biases subsequently influence estimates of N , is needed to evaluate the efficacy of the approach under a range of scenarios.

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is a species of freshwater mussel native to the Mississippi River and Laurentian Great Lakes-St. Lawrence River drainages of North America. This mussel has experienced population declines across large parts of its distribution and is imperiled in many jurisdictions.

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Genomic tools are lacking for invasive and native populations of sea lamprey (). Our objective was to discover single nucleotide polymorphism (SNP) loci to conduct pedigree analyses to quantify reproductive contributions of adult sea lampreys and dispersion of sibling larval sea lampreys of different ages in Great Lakes tributaries. Additional applications of data were explored using additional geographically expansive samples.

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Diversity in life history tactics contributes to the persistence of a population because it helps to protect against stochastic environments by varying individuals in space and time. However, some life history tactics may not be accounted for when assessing the demographic viability of a population. One important factor in demographic viability assessments is cohort replacement rate (CRR), which is defined as the number of future adults produced by an adult.

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Pelagic dispersal of most benthic marine organisms is a fundamental driver of population distribution and persistence and is thought to lead to highly mixed populations. However, the mechanisms driving dispersal pathways of larvae along open coastlines are largely unknown. To examine the degree to which early stages can remain spatially coherent during dispersal, we measured genetic relatedness within a large pulse of newly recruited splitnose rockfish (Sebastes diploproa), a live-bearing fish whose offspring settle along the US Pacific Northwest coast after spending up to a year in the pelagic environment.

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