Caryn presents keynote address at European Malacological Congress

Caryn attended the 8th European Malacological Congress in Krakow, Poland, Sept 10 -14, where she gave an invited keynote address over ecosystem services provided by freshwater mussels.

Katie Murphy and Patrick Olson finish MS degrees

Katie Murphy and Patrick Olson both finished their MS degrees in July. Katie will be working for the Kansas Department of Environmental Quality in Topeka, and Patrick is looking for a job in the Fort Collins area. We wish them both a great future and will miss them!


Brent Tweedy presents his PhD work to the Biology Department

Brent discusses his research on freshwater mussels and interactions between climate-related increases in temperature and mercury contamination in the environment in a seminar presented to the Biology Department on April 19.



Kiamichi River and water scarcity

The Kiamichi watershed is now a case study for an international group examining water scarcity and social-ecological systems.

Congratulations to Traci Popejoy for her new publication in Hydrobiologia.

Popejoy, T., C. R. Randklev, S. Wolverton & L. Nagaoka. 2017. Conservation implications of late Holocene freshwater mussel remains of the Leon River in central Texas. Hydrobiologia  DOI 10.1007/s10750-016-3041-y


We are looking for a postdoc to join our lab


Shifting hotspots: How do consumer aggregations interact to influence resource heterogeneity and fluxes in streams?

We are seeking a Postdoctoral Associate to work on an NSF funded project examining how interacting groups of consumers influence resource heterogeneity in streams. This is a collaborative project between Caryn Vaughn at the University of Oklahoma and Keith Gido at Kansas State University. The postdoc would be based at the University of Oklahoma in Norman. Start date is flexible, but we would like someone to start as soon as possible. Caryn is here at the meeting and can be reached at The project is described below.

Aggregations of consumers create hotspots of nutrient regeneration and material flux that promote resource heterogeneity, increasing biodiversity. Understanding how different types of aggregations interact to influence resource distribution and fluxes is a key knowledge gap, particularly in how these dynamics change across spatial and temporal scales and environmental gradients. Stream fish and mussel assemblages are known to generate biogeochemical hotspots, but have very different characteristics based on species life history and behavior. Long-lived mussels are localized, stable, immobile, long-term hotspots that provide relatively constant nutrient subsidies. Shorter-lived fishes are mobile, widespread, short-term hotspots that provide nutrient subsidies more dependent on hydrologic conditions.

Our project asks: (1) Where and when do fish and mussel hotspots overlap? and (2) How does overlap between these groups influence nutrient recycling and the distribution of resources throughout a stream network? We are using an integrative approach that incorporates species distribution mapping, correlative field studies and a mechanistic mesocosm experiment. To determine the spatial and temporal overlap of mussel and fish hotspots, a biomass distribution model will be generated for mussels and fishes under different hydrologic conditions in two rivers. To determine where and when each group’s function is strongest, path analysis will be used to characterize associations between nutrient dynamics and resource distribution when mussels and fish overlap (summer low flows) and when fish are more dispersed (fall higher flows). To explore mechanistic contributions of mussel and fish assemblages to nutrient and food web dynamics, experiments will be performed in large, replicated, flow-through experimental streams where the movement of nutrients from consumer aggregates (mussel and fish excreta) through the rest of the food web will be tracked with stable isotopes. Lastly, ecosystem dynamics will be scaled to whole rivers using fish and mussel distribution and hydrologic data generated in the field study.

Social assessment of ecosystem services


We have a new paper out that shows how social assessment of ecosystem services can be used to weigh tradeoffs among water resource uses for future watershed management and planning.  


Welcome Traci Popejoy, new PhD student

I am interested in conservation biology, biogeography and community ecology in freshwater systems. I believe multiple forms of evidence are essential to support conservation discussions. For my master’s thesis, I compared freshwater mussel shells from two archaeological sites to a contemporary survey and discussed the conservation implications of this comparison, such as potential habitat change. I look forward to adding to my ‘conservation tool box’ by researching nutrient cycling in Oklahoma streams.traciweb2