Dr. Stuart E. G. Findlay
Aquatic Ecologist
Ph.D., 1981, University of Georgia

Dr. Findlay's research interests encompass characterization and microbial assimilation of dissolved organic carbon in aquatic ecosystems, delivery of carbon from terrestrial to aquatic ecosystems, carbon and nutrient processing in tidal wetlands and ecosystem functions mediated by submerged aquatic vegetation. He has been conducting research on the Hudson River ecosystem for over eighteen years, and is interested in watershed restoration issues as well as a variety of approaches to making scientific information more useful for ecosystem management.

Current Research

Stream Bacterial Communities: When is Function Linked to Structure?
We have carried out a diversity of small and mesocosm-scale experiments, in conjunction with regionally distributed field sampling, to assess when the composition of stream benthic bacterial communities corresponds with differences in stream metabolic activities. We apply multiple measures of functional similarity including assays of extra cellular enzymes to determine what classes of dissolved organic matter are being degraded. We find large differences in carbon processing among streams with weaker differences in community composition. (Findlay, S. E. G., and R. L. Sinsabaugh. Large-scale variation in subsurface stream biofilms: A cross-regional comparison of metabolic function and community similarity. Microbial Ecology. In press.)

Hudson River Habitats: Submersed Aquatic Vegetation
Submersed aquatic vegetation (SAV) is an important habitat in the tidal freshwater Hudson River. We have investigated a wide range of functions in SAV beds including maintenance of high dissolved oxygen, effects on suspended sediment and habitat value. A variety of characteristics ranging in scale from patch-level to 10's of km were necessary to account for inter-bed variability in performance of multiple functions. Moreover, large inter-annual variability makes it more difficult to assess or predict patch performance at given locations or specific times. (Findlay, S. E. G., W. C. Nieder, and D. T. Fischer. 2006. Multi-scale controls on water quality effects of submerged aquatic vegetation in the tidal freshwater Hudson River. Ecosystems 9:84-96.)

Hudson River Habitats: Wetlands
There are roughly 200 tidal freshwater wetlands fringing the Hudson from the Tappan Zee region to the Federal Dam in Troy. Understanding how these habitats contribute to the whole ecosystem requires simple tools to assess multiple functions (habitat for fishes, improvement in water quality) across many sites as well as insight into the many potential factors altering natural functions. We have developed and validated simple indicators of twelve functions and applied this approach to 15 sites along the Hudson (Findlay, S. E. G., E. Kiviat, W. C. Nieder, and E. A. Blair. 2002. Functional assessment of a reference wetland set as a tool for science, management and restoration. Aquatic Science 64:107-117). We are presently relating some of these simple indicators to other processes such as nutrient transformations and oxygen depletion within a range of wetlands. This work has answered the frequently asked question about whether the presence of the railroad embankment has led to deterioration in wetland function.

Increased Loss of DOC from Terrestrial Systems:
Carbon released from terrestrial ecosystems is an important source of organic matter in most streams, lakes and rivers. In the Hudson River there has been a doubling in concentration of dissolved organic carbon over the past 15 years (Findlay, S. E. G. 2005. Increased carbon transport in the Hudson River: unexpected consequence of nitrogen deposition? Frontiers in Ecology and the Environment 3:133-137.) and we are pursuing various possible mechanisms.