OpportunityTitle: Environmental Life History and Genetic Structure of River Sturgeon (Scaphirhynchus spp.) in the Lower Mississippi River
AdditionalInformationOnEligibility: This opportunity is restricted to non-federal partners of the Great Rivers Region Cooperative Ecosystems Studies Unit (CESU).
Description: Background:Shovelnose Sturgeon (Scaphirhynchus platorynchus) and Pallid Sturgeon (S. albus), collectively referred to as river sturgeon (Scaphirhynchus spp.), inhabit medium to large-sized rivers within the Central United States. The Pallid Sturgeon was listed as Endangered by the USFWS in 1990 and the Shovelnose Sturgeon was listed in 2010 as Threatened under the Similarity-of-Appearance provision of the Endangered Species Act where the two species are sympatric (Jordan et al. 2016; Phelps et al. 2016). Both species inhabit the Lower Mississippi River (LMR).Evaluating common life history patterns across life stages (e.g. spawning reaches, larval dispersal patterns, large-scale adult movement patterns) within the context of meta-population dynamics of both Pallid and Shovelnose Sturgeon throughout the species range is critical for maintaining their habitat along the Mississippi River. The primary objective of this project is to utilize archived tissue samples (e.g., fin clip, pectoral ray) collected by ERDC researchers during the course of their past and/or current Pallid Sturgeon monitoring efforts within the LMR to assess common environmental life history patterns and genetic structure of both Shovelnose and Pallid Sturgeon within the LMR.Brief Description of Anticipated Work:Required Work Objectives: One approach for evaluating environmental life history patterns is with trace element or stable isotope analysis, which provides a comparative evaluation of unique isotopic signatures between defined sampling units or events. Within aquatic systems, the methodology builds upon the development of a water chemistry signature gradient which is based on discriminating stable isotope components (e.g., Sr:Ca concentrations) which becomes the known reference condition utilized for subsequent comparative purposes. This technique has been applied to multiple taxa (e.g., molluscs, fishes) to address a range of broad based ecological questions such as re-creating historic hydrologic conditions and identifying feeding habitats. More recently, Phelps et al. (2012) utilized stable isotope analysis on fin ray sections to determine origin and environmental history of young-of-year river sturgeon in the Missouri and Middle Mississippi rivers.Currently, ERDC has nearly 250 unique records representing approximately 500 specimens (larval sturgeon; whole body) and approximately 280 samples (juvenile and adult; pectoral ray) of river sturgeon to be available for stable isotope analyses. ERDC compiled one round of water samples from the LMR in 2014 and those data will be available by the candidates for integration into the water chemistry signature library. In addition, a second set of water chemistry samples will be collected by ERDC to better understand inter-year variability.Use of molecular techniques in ecology and conservation has grown considerably over the past several decades with the type of technique utilized dependent upon the research question and the details needed (Allan and Max 2010). Understanding the genetic population structure of sturgeon species can provide great insight into conservation-based agendas (Wirgin et al. 1997; Anders et al. 2011) and has become a mainstay within many programs (Dugo et al. 2004; Wirgin et al. 2005; Shrey and Heist 2007). A methodological approach similar to the techniques employed by Jordan et al. (2019) to evaluate congruence between morphological, meristic and molecular assessments of Pallid Sturgeon populations would be an appropriate technique to assess population structure within river sturgeon in the LMR. This approach incorporated microsatellite genotypes at specific loci and the software package STRUCTURE to assess genomic variability within and between sample units.ERDC has approximately 500 tissue samples (400 adult sturgeon, fin clips; 100 larval sturgeon, ETOH whole body) primarily from the LMR to be included in the sturgeon molecular assessment.Identified project tasks are: Construct environmental life history attributes for larval, juvenile and adult river sturgeon to evaluate common life history patterns. Isotope profiles obtained from sampled fish will be compared to the stable isotope library obtained from the LMR water samples to determine origin and environmental life history. Compare those life history patterns with similar samples from the Middle Mississippi and Missouri Rivers. Evaluate meta-population dynamics and genetic structure of Pallid and Shovelnose Sturgeon from the LMR using genetic markers and compare those results with similar studies from throughout both species ranges to provide a greater knowledge base for range-wide conservation and management planning.Deliverables will include written products that address the following: Comparative assessment of environmental life history patterns of Shovelnose and Pallid Sturgeon within the LMR, and compare these patterns to published data throughout the species range. Genetic identification of all samples included in the molecular analysis component. Genetic population structure of Pallid and Shovelnose Sturgeon within the LMR.Successful applicants should have a familiarity of sturgeon life history strategies and a general understanding of range-wide issues for both species. The candidates should have sufficient experience with elemental microchemistry and genetic analyses and a record that demonstrates research experience with collecting and analyzing these types of data. Candidates will adhere to recognized standards according to USFWS recommended data acquisition and quality control protocols for all laboratory processes and subsequent analyses. The candidates will be required to prepare a Statement of Work and Work Plan regarding the research to be conducted. The candidates will also be required to submit status reports to accompany billing invoices (monthly or quarterly) and one (1) annual report each year of the cooperative agreement to provide updates on data collection and analysis.Public Benefit:Success in these studies will benefit the public by promoting the recovery of the endangered Pallid Sturgeon. Successful integration of study results will maintain, improve and eventually expand critical habitat features necessary for recovery of the species and ultimately respond in increases in population levels across the species range.
GrantorContactEmailDescription: Anna Crawford
GrantorContactText: Anna Crawford &lt;br/&gt;Grantor &lt;br/&gt;Phone 601-634-5320