Altamaha watershed nutrient budgets Dr. Merryl Alber University of Georgia

Dept. of Marine Sciences University of Georgia Athens Georgia 30602-3636 USA

malber@uga.edu https://marsci.uga.edu/directory/people/merryl-alber https://orcid.org/0000-0002-9467-4449 Georgia Coastal Ecosystems LTER Project

Dept. of Marine Sciences University of Georgia Athens Georgia 30602-3636 USA

gcelter@uga.edu https://gce-lter.marsci.uga.edu/ Dr. Merryl Alber University of Georgia

Dept. of Marine Sciences University of Georgia Athens Georgia 30602-3636 USA

malber@uga.edu https://marsci.uga.edu/directory/people/merryl-alber https://orcid.org/0000-0002-9467-4449 Principal investigator 2004-01-01 2006-12-31 Dr. Sylvia C. Schaefer University of Georgia

Dept. of Marine Sciences University of Georgia Athens GA 30602-3636 USA

sylvia@uga.edu Graduate research assistant 2004-01-01 2006-12-31 2026

M. Alber (UGA) and S. Schaefer (Ph.D. student, UGA) have developed complete nitrogen and phosphorus budgets for the watershed of the Altamaha River for 6 time points between 1954 and 2002 (Schaefer and Alber 2007b, Figure 6). Fertilizer tended to be the most important input of both N and P to the watershed, but net food and feed import increased in importance over time and was the dominant source of N input by 2002. When considered on a sub-watershed basis, fertilizer input tended to be highest in the middle portions of the watershed (Little Ocmulgee, Lower Ocmulgee and Lower Oconee sub-watersheds) whereas net food and feed imports were highest in the upper reaches (Upper Oconee and Upper Ocmulgee sub-watersheds). The different patterns and sources of nutrients has implications for which types of management actions would be most appropriate for reducing nutrient input from different sub-basins.

Question 1: What are the long-term patterns of environmental forcing to the coastal zone? (more information)

LTER NSF Altamaha River Georgia Ocmulgee Oconee GCE 1954 fertilizer nitrogen phosphorus watersheds Overall geographic extent of the research project -81.582311 -81.237936 31.401403 31.296034 2004-01-01 2006-12-31

National Science Foundation grant number OCE-9982133. Additional funding: Coastal Incentive Grant, Georgia Department of Natural Resources; Environmental Protection Agency STAR grant

estuary marsh complex Altamaha River - Altamaha River transect used for GCE quarterly hydrographic monitoring surveys. Nominal profiling stations are defined every 2km from -4km to 40km (relative to station 0km at the line of demarcation), based on an estimated Thalweg line running up the main river channel. -81.582311 -81.237936 31.401403 31.296034 Alber, M., Schaefer, S.C., Pomeroy, L.R., Sheldon, J.E. and Joye, S.B. 2008. Presentation: Nitrogen inputs to the Altamaha River estuary (Georgia, USA): a historic analysis. American Society of Limnology and Oceanography, 3/08, Orlando, FL. Schaefer, S.C. and Alber, M.A. 2007. Temporal and spatial trends in nitrogen and phosphorus inputs to the watershed of the Altamaha River, Georgia, USA. Biogeochemistry. 86(3):231-249. (DOI: 10.1007/s10533-007-9155-6) http://www.springerlink.com/content/233v31u287300447/ Schaefer, S.C. 2006 Nutrient budgets for watersheds on the southeastern Atlantic coast of the United States: temporal and spatial variation. M.S. Thesis, University of Georgia, Athens, Georgia, 105 pp. Schaefer, S.C. and Alber, M. 2006. Nutrient inputs to the Altamaha River Watershed, 1954-2002. Southeastern Estuarine Research Society, Savannah, Georgia. Schaefer, S.C. and Alber, M. 2005. Trends in agricultural sources of nitrogen in the Altamaha River watershed. In: Hatcher, K.J. Proceedings of the 2005 Georgia Waters Resources Conference, Institute of Ecology, University of Georgia, Athens, Georgia. http://gce-lter.marsci.uga.edu/public/files/pubs/SSchaefer_GWRC_Paper_2005.pdf Alber, M., Pomeroy, L.R., Sheldon, J.E. and Schaefer, S.C. 2005. Presentation: Forty years of watershed nitrogen inputs and estuarine response in the Altamaha River estuary (Georgia, USA). Symposium on "Examining nutrient enrichment effects on coastal ecosystems through comparative ecological approaches and perspectives". 2005 Estuarine Research Federation Meeting. October 16-20, 2005, Norfolk, Virginia. Spatial distribution of total inputs of N and P to sub-watersheds of the Altamaha River. All values in kg km-2yr-1. (Source: Schaefer and Alber 2007b). https://gce-lter.marsci.uga.edu/public/resources/projects/Fig2AlberQ1.png