Continental-scale overview of stream primary productivity, its links to water quality, and consequences for aquatic carbon biogeochemistry

Streams and rivers have a limited spatial extent, but are increasingly recognized as key components of regional biogeochemical cycles. The collective metabolic processing of organisms, known as ecosystem metabolism, is centrally important to nutrient cycling and carbon fluxes in these environments, but is poorly integrated into emerging biogeochemical concepts. This line of inquiry lags behind other aspects of regional biogeochemistry because of the lack of long-term, regionally-diverse studies of stream metabolism. With a few exceptions, metabolism studies have focused on small headwater catchments using short-term (days to weeks) observation. As a consequence, basic patterns and controls of this fundamental process, such as seasonality, response to anthropogenic stressors, and interactions with carbon and nutrient cycling are not well understood.

The U.S. Geological Survey maintains a large network of high-frequency oxygen, temperature, and discharge sensors that generate the raw information needed to estimate stream metabolism. In many cases, these sensors have been in operation for years, making this the largest existing source of potential data by several orders of magnitude. However, the observational data have not been assembled and analyzed for questions relating to stream metabolism.

We propose to collate and analyze existing U.S. Geological Survey sensor data to create an open, national database of stream oxygen data from which we will calculate stream metabolism. We are uniquely positioned to open the black box of stream metabolism to address pressing biogeochemical questions at a scale that has not been considered previously: 1) What is annual stream metabolism in the conterminous U.S.?; 2) What is the role of streams and rivers in regional-scale carbon cycling?; 3) Can we detect trends in stream metabolism in response to anthropogenic changes? We have assembled a diverse, international team with the required expertise to assemble, analyze, and interpret this dataset.



Publication(s):

Appling, A. P., Hall, R. O., Jr., Yackulic, C. B., & Arroita, M. (2018). Overcoming equifinality: Leveraging long time series for stream metabolism estimation. Journal of Geophysical Research: Biogeosciences, 123, 624–645. https://doi.org/10.1002/2017JG004140

Appling, Alison P., Jordan S. Read, Luke A. Winslow, Maite Arroita, Emily S. Bernhardt, Natalie A. Griffiths, Robert O. Hall Jr., et al. “The Metabolic Regimes of 356 Rivers in the United States.” Scientific Data 5 (December 11, 2018): 180292.

Bernhardt, E. S., Heffernan, J. B., Grimm, N. B., Stanley, E. H., Harvey, J. W., Arroita, M., Appling, A. P., Cohen, M. J., McDowell, W. H., Hall, R. O., Read, J. S., Roberts, B. J., Stets, E. G. and Yackulic, C. B. (2017), The metabolic regimes of flowing waters. Limnol. Oceanogr.. doi:10.1002/lno.10726

Bernhardt ES, Savoy P, Vlah MJ, Appling AP, Koenig LE, Hall RO, Arroita M, Blaszczak JR, Carter AM, Cohen M, Harvey JW. Light and flow regimes regulate the metabolism of rivers. Proceedings of the National Academy of Sciences. 2022 Feb 22;119(8).


Savoy, P. , Appling, A. P., Heffernan, J. B., Stets, E. G., Read, J. S., Harvey, J. W. and Bernhardt, E. S. (2019), Metabolic rhythms in flowing waters: An approach for classifying river productivity regimes. Limnol Oceanogr. doi:10.1002/lno.11154