You are here:
Resolving drivers of variability in estuarine metabolism from sustained observations of water quality in the SE US
Citation:
MURRELL, M. C., J. M. CAFFREY, K. R. STRAUB, J. D. HAGY, M. WOODREY, S. PHIPPS, J. WANAT, L. EDMISTON, AND M. SHIRLEY. Resolving drivers of variability in estuarine metabolism from sustained observations of water quality in the SE US. Presented at Coastal & Estuarine Research Federation (CERF) 2011 Conference, Daytona Beach, FL, November 06 - 10, 2011.
Impact/Purpose:
To examine trends in water quality in long-term monitoring data collected at five estuarine systems of NOAA's National Estuarine Research Reserve System
Description:
We examine trends in water quality in long-term monitoring (10-15 y) data collected at 5 estuarine systems of NOAA’s National Estuarine Research Reserve System: Grand Bay, MS; Weeks Bay, AL; Apalachicola Bay, FL; Rookery Bay, FL, and Guana Tolomatos and Matanzas Rivers, FL. These estuaries vary in size, flow regime, watershed area, anthropogenic influence, and land use. Water quality variables, include water temperature, salinity, dissolved oxygen, and pH were measured with in-situ data sondes at multiple sites in each system as part of the National Estuarine Research Reserves System Wide Monitoring Program. We examine seasonal and interannual patterns in these water quality data for temporal coherence both within and among the estuaries. Preliminary analysis shows strong coherence among all systems in annual salinity anomaly, calculated as the deviation of annual mean salinity from the long term mean, with highest salinity observed during the droughts of 2000-2002 and 2006-2007. The frequency of hypoxia (DO < 2 mg/L), used as an index of potential eutrophication, occurred infrequently at some sites (<1% of the record) and regularly at others (up to 17% of the annual record in Weeks Bay). The dissolved oxygen data will also be used to calculate daily gross production, respiration and net ecosystem metabolism (NEM) parameters. We hypothesize that warmer temperatures or higher flow regimes will cause a decrease in NEM, while relatively cooler temperatures or lower flow regimes will result in higher NEM. Consistent with this hypothesis, prior analyses of Apalachicola and Weeks Bays data showed that gross production decreased during high flow periods, likely due to changes in turbidity and residence time.