Quantifying Metabolically Driven pH and Oxygen Fluctuations in US Nearshore Habitats at Diel to Interannual Time Scales
We compiled and examined 15 years (2002–2016) of high-frequency monitoring data from the National Estuarine Research Reserve System (NERRS) to characterize diel to interannual variability of pH and dissolved oxygen (DO, % saturation) across 16 diverse, shallow-water habitats along the US Atlantic, Gulf of Mexico, Caribbean, and Pacific coasts. We asked whether these systems exhibit a common pH/DO relationship, whether there were detectable interannual trends in temperature, pH, and DO within and across systems, and how pH/DO dynamics would relate to measured levels of nutrients and chlorophyll. Our analyses confirmed that large, metabolically driven, and thus concurrent fluctuations of pH and DO are a unifying feature of nearshore habitats. Moreover, we derived well-constrained relationships that predict (i) monthly mean pH or (ii) mean diel pH fluctuations across systems based on habitat mean salinity and (i) mean DO or (ii) mean diel DO fluctuations. This suggests that common metabolic principles drive diel to seasonal pH/DO variations within as well as across a diversity of estuarine environments. Yearly pH and DO anomalies did not show monotonous trends over the study period and differed considerably between sites and regions. However, weekly anomalies of means, diel minima, and diel ranges of pH and DO changed significantly over time and were strongly correlated to temperature anomalies. These general patterns lend strong empirical support to the notion that coastal acidification—in addition to being driven by eutrophication and atmospheric CO2 increases—is exacerbated simply by warming, likely via increasing community respiration. Nutrient and chlorophyll dynamics were inversely related in these shallow, well-mixed systems, but higher nutrient levels were still associated with lower pH and lower DO levels in most, but not all, systems. Our analyses emphasize the particular dynamics of nearshore habitats and the critical importance of NERRS and its system-wide monitoring program.
KeywordsEutrophication Ecosystem metabolism Oxygen saturation Ocean acidification Multistressor Climate change National Estuarine Research Reserve System (NERRS)
This study would not have been possible if the NERRS System-Wide Monitoring Program did not exist. Our gratitude to the entirety of the SWMP technical staff for their dedicated and meticulous efforts in maintaining this valuable program for more than two decades cannot be overstated.
- Barton, A., B. Hales, G.G. Waldbusser, C. Langdon, and R.A. Feely. 2012. The Pacific oyster, Crassostrea gigas, shows negative correlation to naturally elevated carbon dioxide levels: implications for near-term ocean acidification effects. Limnology and Oceanography 57: 689–710.CrossRefGoogle Scholar
- Beck, M.W., K.L. Heck, K.W. Able, D.L. Childers, D.B. Eggleston, B.M. Gillanders, B.S. Halpern, C.G. Hayes, K. Hoshino, and T.J. Minello. 2003. The role of nearshore ecosystems as fish and shellfish nurseries. Issues in Ecology 11: 1–12.Google Scholar
- Breitburg, D.L., J. Salisbury, J.M. Bernhard, W.-J. Cai, S. Dupont, S.C. Doney, K.J. Kroeker, L. Levin, W.C. Long, L.M. Milke, S.H. Miller, B. Phelan, U. Passow, B.A. Seibel, A.E. Todgham, and A.M. Tarrant. 2015b. And on top of all that… coping with ocean acidification in the midst of many stressors. Oceanography 28: 48–61.CrossRefGoogle Scholar
- Buskey, E., M. Bundy, M. Ferner, D. Porter, W. Reay, E. Smith, and D. Trueblood. 2015. System-wide monitoring program of the National Estuarine Research Reserve System: research and monitoring to address coastal management issues. In Coastal ocean observing systems: advances and syntheses, ed. Y. Liu, H. Kerkering, R. Weisberg, 392–414. Cambridge, USA: Academic Press.Google Scholar
- Cai, W.J., Z.A. Wang, and Y. Wang. 2003b. The role of marsh-dominated heterotrophic continental margins in transport of CO2 between the atmosphere, the land-sea interface and the ocean. Geophysical Research Letters 30, 1849. http://dx.doi.org/10.1029/2003GL017633.
- Cloern, J.E., P.C. Abreu, J. Carstensen, L. Chauvaud, R. Elmgren, J. Grall, H. Greening, J.O.R. Johansson, M. Kahru, and E.T. Sherwood. 2016. Human activities and climate variability drive fast-paced change across the world’s estuarine–coastal ecosystems. Global Change Biology 22: 513–529.CrossRefGoogle Scholar
- Herrmann, M., R.G. Najjar, W.M. Kemp, R.B. Alexander, E.W. Boyer, W.J. Cai, P.C. Griffith, K.D. Kroeger, S.L. McCallister, and R.A. Smith. 2015. Net ecosystem production and organic carbon balance of US East Coast estuaries: a synthesis approach. Global Biogeochemical Cycles 29: 96–111.CrossRefGoogle Scholar
- Hofmann, G.E., J.E. Smith, K.S. Johnson, U. Send, L.A. Levin, F. Micheli, A. Paytan, N.N. Price, B. Peterson, Y. Takeshita, P.G. Matson, E.D. Crook, K.J. Kroeker, M.C. Gambi, E.B. Rivest, C.A. Frieder, P.C. Yu, and T.R. Martz. 2011. High-frequency dynamics of ocean pH: a multi-ecosystem comparison. PloS One 6: e28983.CrossRefGoogle Scholar
- Holland, A.F., D.M. Sanger, C.P. Gawle, S.B. Lerberg, M.S. Santiago, G.H. Riekerk, L.E. Zimmerman, and G.I. Scott. 2004. Linkages between tidal creek ecosystems and the landscape and demographic attributes of their watersheds. Journal of Experimental Marine Biology and Ecology 298: 151–178.CrossRefGoogle Scholar
- Kemp, W.M., and J.M. Testa. 2011. Metabolic balance between ecosystem production and consumption. In Treatise on estuaries and coastal science, vol. 7, ed. E. Wolansky and D. McLusky, 83–118. Oxford: Elsevier LtdGoogle Scholar
- Kneib, R.T. 1997. The role of tidal marshes in the ecology of estuarine nekton. Oceanography and Marine Biology 35: 163–220.Google Scholar
- Moore, K.A., and J.C. Jarvis. 2008. Environmental factors affecting recent summertime eelgrass diebacks in the lower Chesapeake Bay: implications for long-term persistence. Journal of Coastal Research 55: 135–147.Google Scholar
- Odum, E.P. 1961. The role of tidal marshes in estuarine production. The Conservationist 15: 12–15.Google Scholar
- Porter, D.E., T. Small, D.White, M. Fletcher, A. Norman, D. Swain, and J. Friedmann. 2004. Data management in support of environmental monitoring, research, and coastal management. Journal of Coastal Research 45: 9–16.Google Scholar
- Riley, G.A. 1972. Patterns of production in marine ecosystems. In Ecosystem structure and function, ed. J. A. Wiens, 91–112. Corvallis: University of Oregon Press.Google Scholar
- Rockstrom, J., W. Steffen, K. Noone, A. Persson, F.S. Chapin, E.F. Lambin, T.M. Lenton, M. Scheffer, C. Folke, H.J. Schellnhuber, B. Nykvist, C.A. de Wit, T. Hughes, S. van der Leeuw, H. Rodhe, S. Sorlin, P.K. Snyder, R. Costanza, U. Svedin, M. Falkenmark, L. Karlberg, R.W. Corell, V.J. Fabry, J. Hansen, B. Walker, D. Liverman, K. Richardson, P. Crutzen, and J.A. Foley. 2009. A safe operating space for humanity. Nature 461: 472–475.CrossRefGoogle Scholar
- Wenner, E., D. Sanger, M. Arendt, A.F. Holland, and Y. Chen. 2004. Variability in dissolved oxygen and other water-quality variables within the national estuarine research reserve system. Journal of Coastal Research 45: 17–38.Google Scholar
- Zhang, J., D. Gilbert, A.J. Gooday, L. Levin, S.W.A. Naqvi, J.J. Middelburg, M. Scranton, W. Ekau, A. Peña, B. Dewitte, T. Oguz, P.M.S. Monteiro, E. Urban, N.N. Rabalais, V. Ittekkot, W.M. Kemp, O. Ulloa, R. Elmgren, E. Escobar-Briones, and A.K. Van der Plas. 2010. Natural and human-induced hypoxia and consequences for coastal areas: synthesis and future development. Biogeosciences 7: 1443–1467.CrossRefGoogle Scholar