5/19/2015  |   15:30 - 15:45   |  102E

HOW TO SAVE AN IMPERILED FAUNA IN AN INCREASINGLY THREATENED LANDSCAPE: FROM ENDANGERED SPECIES TO ECOSYSTEM SERVICES Freshwater mussels are one of the world’s most imperiled faunas, largely because their life history traits make them highly vulnerable to climate change, habitat destruction and alteration, population fragmentation, and introduction of non-native species. Although most mussel species are declining, much of past work in mussel conservation has focused on documenting and propagating only the rarest species. More recent research has highlighted that while conservation of rare species is important it is the common species that provide the majority of ecosystem services because mussels are “biofilters” that transfer energy and nutrients in aquatic foodwebs and even into terrestrial ecosystems. The biophysical processes performed by mussels vary with species and environmental conditions, particularly flow and temperature. These biophysical processes can be quantified and assigned value as ecosystem services. Further, the social demand for these services can also be assessed and compared, which is particularly important in our increasingly human-dominated landscapes. My lab is using this approach to inform reservoir management and environmental flows in the south central US where extreme droughts are predicted to become more frequent, intense and persistent.

Caryn C. Vaughn (Primary Presenter/Author), University of Oklahoma, cvaughn@ou.edu;

5/19/2015  |   15:45 - 16:00   |  102E

OUR FRESHWATER FUTURES: INTEGRATING ANIMALS AND ECOSYSTEM MODELS Does aquatic biodiversity loss or homogenization have negative consequences for ecosystem function? How and why does cultural eutrophication (i.e., nutrient enrichment) impact the distribution and abundance of aquatic macrofauna such as invertebrates and fishes? Efforts by freshwater ecologists throughout this field’s history have enlightened our understanding of these questions by examining controls on secondary production and by linking energy and element cycling within aquatic biota using a stoichiometric framework. We now understand that food resource amounts and elemental ratios can alter growth and production of aquatic species depending on their particular growth requirements. Further, growth requirements vary across species due to differences in body plan and life history. The difference between the resource elemental ratios and growth-demand elemental ratios can predict the function of species in ecosystems. Our future research endeavors in this area will strive to use and modify these basic frameworks to provide a predictive understanding of the relationship between biodiversity and ecosystem function and the effects of scarce or abundant nutrients on animals in ecosystems.

Michelle Evans-White (Primary Presenter/Author), University of Arkansas, mevanswh@uark.edu;

5/19/2015  |   16:00 - 16:15   |  102E

A BRIEF HISTORY OF STREAM FISH ECOLOGY AND A SPECULATIVE LOOK FORWARD Freshwater fishes surprisingly compose >40% of all fish diversity, far more than the proportional availability of fresh to salt water. The variety of fishes inhabiting flowing waters, from small headwater streams to great rivers, has long inspired study. Stream fish ecologists have pioneered research on how habitat and species interactions influence variation in community composition, in space and time. Studies of migration and dispersal have illuminated fishes as linkages within diverse landscapes. As landscapes and river systems have been increasingly altered to meet other human needs, studies have focused on understanding fish population responses to water diversions and dams, and urban and agricultural land use. Research on stream fishes entails interesting challenges in quantifying populations that are difficult to observe directly, and future work is likely to employ novel methods and technologies for detecting species and tracking populations in relation to environmental change. There is a wide scope for future discoveries concerning resilience (or less optimistically, demise) of stream fishes in our changing world, and consequences for ecological function in stream ecosystems.

Mary Freeman (Primary Presenter/Author), US Geological Survey, mcfreeman@usgs.gov;

5/19/2015  |   16:15 - 16:30   |  102E

OUR FRESHWATER FUTURE AND THE IMPORTANCE OF FISH SPECIES FOR THE FUNCTIONING OF STREAM ECOSYSTEMS Freshwater conservation requires an understanding of the role of species for the functioning of aquatic ecosystems. Species losses and additions (i.e. invasions) are compromising the future of freshwaters as we know them – not only from the perspective of biodiversity but also in terms of the ways ecosystems work. Using studies on tropical fishes, we explore the importance of species on ecosystem processes, and how species losses and additions can reconfigure ecosystems. Research on migratory fishes in the Orinoco and Amazon Basins illustrates their substantial roles for the cycling of nutrients and materials, in addition to ecosystem processes such as seed dispersal. Likewise, our work in southern Mexico shows that species invasions can have large ecosystem consequences, as observed for armored catfish (Loricariidae). Armored catfish are stoichiometrically unique species that have been introduced via the aquarium trade and can form massive aggregations. In addition to devastating once thriving fisheries, armored catfish sequester large amounts of phosphorus in nutrient poor streams and represent significant biogeochemical hotspots. We discuss the critical need to link species to ecosystems for forecasting our freshwater future.

Alexander Flecker (Primary Presenter/Author), Cornell University, Ithaca, NY, USA, asf3@cornell.edu;


Krista Capps (Co-Presenter/Co-Author), University of Georgia, kcapps@uga.edu;
Research in Krista Capps's lab is dedicated to understanding how anthropogenic activities alter community structure and ecosystem processes (e.g., productivity, decomposition, and biogeochemical cycling) in freshwater ecosystems. Much of her research has focused on the impacts of consumers on basal food resources, community structure, and nutrient dynamics in streams and wetlands. To translate scientific knowledge to actionable outcomes, she actively works with community groups and local, state, and federal employees to develop programs that integrate stakeholder concerns into research planning.