Optimizing biodiversity surveys with molecular tools
Our research uses environmental DNA (eDNA) as a powerful, non-invasive tool for monitoring aquatic ecosystems. eDNA is the genetic material shed by organisms into their environment through skin cells, excretions, or other biological materials. By collecting water samples from an ecosystem, eDNA can be used as a comprehensive assessment of biodiversity. We use eDNA tools to detect species, monitor community composition changes over time, and evaluate the impacts of environmental stressors or management actions on biodiversity. We also assess how eDNA tools can be used in combination with other sampling tools to optimize biodiversity surveys in terms of both effort and cost.
Detecting intraspecific genetic diversity with eDNA
While environmental DNA (eDNA) approaches are well established for detecting species presence and biodiversity, little is known about the utility of these methods for gathering population-level genetic information. Our research aims to develop and validate novel approaches to obtain intraspecific genetic information from eDNA samples. Using mesocosm experiments and field-based applications, we target mitochondrial and nuclear genetic markers to estimate population structure, genetic diversity, and species abundance of the invasive round goby (Neogobius melanostomus) in eDNA samples. We are also working with scientists at the USGS Great Lakes Science Center to develop novel eDNA-based metrics of species abundance based on genetic diversity.
Factors influencing the structure and function of fish gut microbiomes
The gut microbiome is closely connected to fish metabolism, development, immunity and overall health status, but the relative influence of host, diet, and environment on their gut microbial communities is not well understood. Current work in our lab uses molecular approaches to characterize the diet and gut microbiome of over a dozen species of sympatric freshwater fishes native to the Meramec River to disentangle the fundamental processes driving variation in the gut microbiome in wild fishes. Other projects have explored the role of life stage and vaccination on the gut microbiome of the ecologically and economically important Atlantic salmon (Salmo salar).
Phenotypic shifts to climate-driven changes in hydrology
Predicting how species traits will respond to environmental changes is crucial for understanding the ecological and evolutionary impacts of climate change. We have examined patterns of phenotypic changes expected under future climatic change scenarios by assessing how body shape is associated with streamflow in minnow species. Populations are not expected to respond uniformly across the species’ ranges, and most species exhibit projected morphologies outside of the current range of morphological variation. These findings suggest local adaptation and spatial heterogeneity in environmental changes interact to influence variation in the degree of expected phenotypic responses to climate change.