Development of Quantitative eDNA Tools to Aid in the Monitoring of Freshwater Mussel Abundance and Breeding Activity Across Multiple River Systems
The Issue: Native freshwater mussels have their highest species diversity in North America and are of special conservation significance. Monitoring for mussel populations is expensive, time consuming, and requires excerpt taxonomic knowledge. Environmental DNA could be used as an additional monitoring and surveying tool. Of particular interest is the use of eDNA for assessing population size in aquatic systems, with the idea that the concentration of eDNA in a sample is reflective of the abundance or biomass of the organisms’ shedding the genetic material. However, the concentration and detectability of eDNA changes with distance from the source in response to several factors. In particular, the movement of eDNA in flowing stream systems is complex.
Addressing the Issue: Our approach is to leverage the unique biology and natural history of freshwater mussels to gain further insight into the use of eDNA tools for species monitoring in riverine systems. We address two main objectives: 1- Develop eDNA transport models and test their ability to aid in the understanding of detection probability as well as test the ability to use these models to back calculate source location and abundances; 2 – Create additional genetic assays to detect spawning behavior of male freshwater mussels. This project will aid in the conservation of freshwater mussels, which are of concern due to the high number of federally listed species, the importance of mussels as indicators of water quality, and cultural significance of these species. We will use a combination of manipulative laboratory studies, field sampling, hydrologic assessment, and numerical modeling to create, test and assess our freshwater mussel eDNA tools.
Next Steps/Future Steps/Results: To date, probe based quantitative PCR assays for three of the four target species have been optimized and tested. An assay for male specific spawning behavior has also been developed and will soon be tested in situ. Laboratory studies are underway to measure shedding rates of target mussel species and assess whether we can detect a change in biomass from shedding rates as well as if temperature and feeing behavior affect eDNA shedding. A 1-dimensional transport model will be created to predict the fate and transport of freshwater mussel eDNA in each river with a more detailed 2D model domain, encompassing a shorter stretch of river immediately downstream of the mussel bed, to evaluate what is gained in understanding if complex hydraulics are included.
The Issue: Native freshwater mussels have their highest species diversity in North America and are of special conservation significance. Monitoring for mussel populations is expensive, time consuming, and requires excerpt taxonomic knowledge. Environmental DNA could be used as an additional monitoring and surveying tool. Of particular interest is the use of eDNA for assessing population size in aquatic systems, with the idea that the concentration of eDNA in a sample is reflective of the abundance or biomass of the organisms’ shedding the genetic material. However, the concentration and detectability of eDNA changes with distance from the source in response to several factors. In particular, the movement of eDNA in flowing stream systems is complex.
Addressing the Issue: Our approach is to leverage the unique biology and natural history of freshwater mussels to gain further insight into the use of eDNA tools for species monitoring in riverine systems. We address two main objectives: 1- Develop eDNA transport models and test their ability to aid in the understanding of detection probability as well as test the ability to use these models to back calculate source location and abundances; 2 – Create additional genetic assays to detect spawning behavior of male freshwater mussels. This project will aid in the conservation of freshwater mussels, which are of concern due to the high number of federally listed species, the importance of mussels as indicators of water quality, and cultural significance of these species. We will use a combination of manipulative laboratory studies, field sampling, hydrologic assessment, and numerical modeling to create, test and assess our freshwater mussel eDNA tools.
Next Steps/Future Steps/Results: To date, probe based quantitative PCR assays for three of the four target species have been optimized and tested. An assay for male specific spawning behavior has also been developed and will soon be tested in situ. Laboratory studies are underway to measure shedding rates of target mussel species and assess whether we can detect a change in biomass from shedding rates as well as if temperature and feeing behavior affect eDNA shedding. A 1-dimensional transport model will be created to predict the fate and transport of freshwater mussel eDNA in each river with a more detailed 2D model domain, encompassing a shorter stretch of river immediately downstream of the mussel bed, to evaluate what is gained in understanding if complex hydraulics are included.