Jobs:Job-00129

From CSDMS
USGS Mendenhall Opportunity in Ecological Transport Processes
USGS, The River Studies Branch, Columbia Environmental Research Center (CERC), , United States
Apply before: 15 April 2020


Posting:
Position:
Mendenhall Research Fellowship
Apply before:
15 April 2020
Apply online:
The hydraulics of material transport are fundamental to physical, chemical, and ecological conditions of rivers. In the ecological sphere, transport of eggs and larvae is a key determinant of dispersal, survival, and recruitment in both endangered and invasive fishes (Braaten and others, 2012; Erwin and Jacobson, 2014; Garcia and others, 2015; Murphy and others, 2016; Erwin and others, 2018; Prada and others, 2019). In larval dispersal, variability of biomechanics associated with larval fish development (from passive transport to development of swimming capabilities) presents substantive challenges to prediction and requires a strong interdisciplinary approach to inquiry. The transport of environmental DNA (eDNA) has emerged as another important research topic in ecological transport because of the potential for using eDNA to detect and quantify populations of aquatic organisms, including invasive species like Asian carps (Klymus and others, 2015; Song and others, 2017) and endangered mussels (Sansom and Sassoubre, 2017; Currier and others, 2018). Dispersal transport processes share many factors in common with eDNA transport including the need to quantify hydrology, hydraulics, dispersion, mixing, decay (mortality), and advection. Both include the methodological challenges of generalizing understanding through computational models at scales relevant to decision making and the practicalities of measuring and sampling in the field.

The River Studies Branch, Columbia Environmental Research Center (CERC), has an ongoing, interdisciplinary research program to inform management and restoration of rivers. This program is funded through partnerships with the USGS Ecosystems Mission Area, US Army Corps of Engineers, and the Department of Defense Strategic Environmental Research and Development Program. We have a new opportunity to develop fundamental research in ecological transport phenomena related to two projects: 1) prediction of larval dispersal of the endangered pallid sturgeon (Scaphirhynchus albus) and 2) development of transport models related to using quantitative eDNA for monitoring freshwater mussel abundance. We seek a post-doctoral fellow with a strong background in hydraulics, turbulence, hydrodynamic modeling, and aquatic ecology; substantial flexibility exists for determining the scope and approach of each project.

Larval dispersal: This project builds on a foundation of extensive field sampling, computational hydrodynamic modeling, and early-life-stage development research on the dispersal of pallid sturgeon larvae in the Missouri River. Key unknowns relate to the biomechanics of larval transport. Two specific issues are how passively drifting larvae are distributed vertically in the water column (which has an important influence on advection and dispersion) and how and when developing larvae transition to holding themselves in the current (settling). While field sampling has provided critical information about these factors, advances in answering these fundamental questions requires a more controlled, experimental approach. Accordingly, we are in the process of building a 11 m x 5 m racetrack flume (“eco-flume”) capable of 1-m depth and current velocities up to 1 m/s. The opportunity involves working with the final design stages and implementation of the flume (and associated instrumentation), design and implementation of experiments, and application of results to computational particle-tracking models.

eDNA transport: This project builds on previous work on eDNA shedding and decay to address how eDNA may be applied to monitoring freshwater mussel abundance in two river systems (Clinch River, Virginia and Big Piney River, Missouri). The Fellow will work with molecular biologists developing eDNA assays and sampling protocols to develop an appropriate hydrodynamic transport model to evaluate mixing, dilution, decay, and biogeochemical interactions as eDNA is advected downstream from mussel beds. The project is based on selected reaches of the two rivers but is open-ended as to the complexity of the modeling approach needed. The incumbent will develop the modeling approach and implement the model for the selected field sites, using field-sampled eDNA to evaluate model performance.

At CERC, the fellow will have broad opportunities for collaboration with existing interdisciplinary teams of biologists, chemists, and physical scientists with extensive experience in studying riverine ecological processes. Extramural collaborations are in place with the Saint Anthony Falls Hydraulics Laboratory (University of Minnesota), University of Missouri, Missouri State University, U.S. Fish and Wildlife Service, and the U.S. Army Corps of Engineers. The Fellow can build their research using the River Studies Branch robust cadre of technicians to support field work and development of laboratory instrumentation, and can access existing experience in hydroacoustic surveying, GPS and conventional surveying, and computational modeling (including high-performance computing applications). To support biological aspects of the research, CERC has captive pallid sturgeon, Asian carp, and native mussels for breeding and propagation of experimental subjects. The post-doctoral fellowship will allow for additional collaborative interactions related to large-river ecological processes, sediment transport, hydroacoustics, and habitat assessments, in field and laboratory contexts.

Interested applicants are strongly encouraged to contact the Research Advisor early in the application process to discuss project ideas.
Of interest for:
  • Ecosystem Dynamics Focus Research Group

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