Nutrient Loading Impacts on Estuarine Phytoplankton Size and Community Composition: Community-Based Indicators of Eutrophication
Water quality management strategies focus primarily on reducing nutrient loading in estuaries to limit total chlorophyll a (chl a) to less than 40 μg l−1. However, potential alterations in phytoplankton community composition and subsequent ecological implications below this limit are not generally considered. The effect of moderate loadings of nitrate (N) and phosphate (P) on nutrient-limited phytoplankton composition and cell size was investigated using multiple bioassays from 2014 to 2016 to evaluate phytoplankton community shifts below the 40 μg l−1 threshold. Water collected from North Inlet Estuary, SC, was spiked with 20 μmol l−1 N and of 10 μmol l−1 P and incubated for 2 days. The proportion of diatoms, cryptophytes, cyanobacteria, prasinophytes, and chlorophytes was calculated for each treatment (i.e., control and NP addition) and for two size fractions (i.e., < 20 μm and whole water). Phytoplankton biomass increases were below the 40 μg chl a l−1 threshold and resulted in a variable shift in phytoplankton group abundances, likely due to the initial community composition. Nutrient additions enhanced the biomass of the fraction smaller than 20 μm and the proportion of diatoms at the expense of cyanobacteria and cryptophytes. Shifts in community composition could have potential cascading impacts on higher trophic levels in the estuary. These results highlight the importance of characterizing and monitoring eutrophication using abundances of algal groups in addition to total biomass as ecologically relevant alterations may occur at low levels of eutrophication.
KeywordsChlorophyll a Estuary Eutrophication Nutrients Photopigments
We thank C. Doll and J.P. Everhart for their assistance with photopigment and nutrient analyses. We also thank Dr. Dianne Greenfield and the anonymous reviewers for their insightful comments and suggestions. This is publication 1867 from the Belle W. Baruch Institute for Marine and Coastal Sciences.
This work was supported by the F. John Vernberg Fellowship, the Slocum-Lunz Foundation, and the SPARC fellowship received from the University of South Carolina and from the Baruch Institute.
Compliance with ethical standards
Conflict of Interest
The authors declare that they have no conflict of interest.
- Allen, D.M., W.B. Allen, R.F. Feller, and J.S. Plunket. 2014. Site profile of the North Inlet–Winyah Bay National Estuarine Research Reserve. Georgetown: North Inlet–Winyah Bay National Estuarine Research Reserve.Google Scholar
- Bell, D.W., S. Denham, E.M. Smith, and C.R. Benitez-Nelson. 2018. Temporal variability in ecological stoichiometry and material exchange in a tidally dominated estuary (North Inlet, South Carolina) and the impact on community nutrient status. Esuaries and Coasts. https://doi.org/10.1007/s12237-018-0430-7.
- Beutel, M.W., R. Duvil, F.J. Cubas, D.A. Matthews, F.M. Wilhelm, T.J. Grizzard, D. Austin, A.J. Horne, and S. Gebremariam. 2016. A review of managed nitrate addition to enhance surface water quality. Critical Reviews in Environmental Science and Technology 46 (7): 673–700.Google Scholar
- Bodeanu, N., and G.R. Uta. 1998. Development of the planktonic algae in the Romanian Black Sea sector in 1981–1996. In Harmful algae, ed. B. Reguera, J. Blanco, M.L. Fernandez, and T. Wyatt, 188–191. Paris: Xunta de Galicia and Intergovernmental Oceanographic Commission of United Nations Educational, Scientific and Cultural Organization.Google Scholar
- Caron, D.A., A.G. Gellene, J. Smith, E.L. Seubert, V. Campbell, G.S. Sukhatme, B. Seegers, B.H. Jones, A.A.Y. Lie, R. Terrado, M.D.A. Howard, R.M. Kudela, K. Hayashi, J. Ryan, J. Birch, E. Demir-Hilton, K. Yamahara, C. Scholin, M. Mengel, and G. Robertson. 2017. Response of phytoplankton and bacterial biomass during a waste water effluent diversion into nearshore coastal waters. Estuarine, Coastal and Shelf Science 186: 223–236.CrossRefGoogle Scholar
- Chislock, M.F., E. Doster, R.A. Zitomer, and A.E. Wilson. 2013. Eutrophication: Causes, consequences, and controls in aquatic ecosystems. Nature Education Knowledge 4 (4): 10.Google Scholar
- Clement, A. and G. Lembeye. 1993. Phytoplankton monitoring program in the fish farming region of South Chile. In T.J. Smayda and Y. Shimizu (Eds.). Toxic phytoplankton blooms in the sea. p. 223–228.Google Scholar
- Ferreira, J.G., J.H. Andersen, A. Borja, S.B. Bricker, J. Camp, M. Cardoso da Silva, E. Garcés, A.S. Heiskanen, C. Humborg, L. Ignatiades, C. Lancelot, A. Menesguen, P. Tett, N. Hoepffner, and U. Claussen. 2011. Overview of eutrophication indicators to assess the environmental status within the European Marine Strategy Framework Directive. Estuarine, Coastal and Shelf Science 93: 117–131.CrossRefGoogle Scholar
- Glibert, P.M., F.P. Wilkerson, R.C. Dugdale, J.A. Raven, C. Dupont, P.R. Leavitt, A.E. Parker, J.M. Burkholder, and T.M. Kana. 2016. Pluses and minuses of ammonium and nitrate uptake and assimilation by phytoplankton and implications for productivity and community composition, with emphasis on nitrogen-enriched conditions. Limnology and Oceanography 61: 165–197.CrossRefGoogle Scholar
- Heisler, J., P.M. Glibert, J.M. Burkholder, D.M. Anderson, W. Cochlan, W.C. Dennison, Q. Dortch, C.J. Gobler, C.A. Heil, E. Humphries, A. Lewitus, R. Magnien, H.G. Marshall, K. Sellner, D.A. Stockwell, D.K. Stoecker, and M. Suddleson. 2008. Eutrophication and harmful algal blooms: A scientific consensus. Harmful Algae 8: 3–13.CrossRefGoogle Scholar
- Higgins, H.W., S.W. Wright, and L. Schlüter. 2011. Quantitative interpretation of chemotaxonomic pigment data. In Phytoplankton pigments—Characterization, chemotaxonomy and applications in oceanography, Eds. Roy, S., C., Llewellyn, E.S., Egeland, G., Johnsen. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA p 257–313.Google Scholar
- IPCC. 2013. Climate Change 2013: the physical science basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Eds: Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex, and P.M. Midgley. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. 1535 pp.Google Scholar
- Lewitus, A.J., D.L. White, R.G. Tymowski, M.E. Geesey, S.N. Hymel, and P.A. Noble. 2005. Adapting the CHEMTAX method for assessing phytoplankton taxonomic composition in Southeastern U.S. estuaries. Coastal and Estuarine Research Federation 28: 160–172.Google Scholar
- Pinckney, J.L., H.W. Paerl, P. Tester, and T.L. Richardson. 2001. The role of nutrient loading and eutrophication in estuarine ecology. Environmental Health Perspectives 109: 699–706.Google Scholar
- Smayda, T.J., 2006. Harmful algal bloom communities in Scottish coastal waters: Relationship to fish farming and regional comparisons—A review: Paper 2006/3. Scottish Executive www.scotland.gov.uk/Publications/2006/02/03095327/16.
- South Carolina Sea Grant Consortium. 1992. Characterization of the physical, chemical and biological conditions and trends in three South Carolina estuaries: 1970–1985. South Carolina Sea Grant Consortium: Charleston.Google Scholar
- Treasurer, J.W., F. Hannah and D. Cox. 2003. Impact of a phytoplankton bloom on mortalities and feeding response of farmed Atlantic salmon, Salmo salar, in west Scotland. Aquaculture 218(1):103–113.Google Scholar
- Vrzel, J., B. Vuković-Gačić, S. Kolarević, Z. Gačić, M. Kračun-Kolarević, J. Kostić, M. Aborgiba, A. Farnleitner, G. Reischer, R. Linke, M. Paunović, and N. Ogrinc. 2016. Determination of the sources of nitrate and the microbiological sources of pollution in the Sava River Basin. Science of the Total Environment 573: 1460–1471.CrossRefGoogle Scholar
- Wells, M.L., V.L. Trainer, T.J. Smayda, B.S.O. Karlson, C.G. Trick, R.M. Kudela, A. Ishikawa, S. Bernard, A. Wulff, D.M. Anderson, and W.P. Cochlan. 2015. Harmful algal blooms and climate change: Learning from the past and present to forecast the future. Harmful Algae 49: 68–93.CrossRefGoogle Scholar