, Volume 19, Issue 2, pp 422–435 | Cite as

Effects of stormwater nutrient discharges on eutrophication processes in nearshore waters of the Florida keys

  • Brian E. Lapointe
  • William R. Matzie


Rainfall events cause episodic discharges of groundwaters contaminated with septic tank effluent into nearshore waters of the Florida keys, enhancing eutrophication in sensitive coral reef communities. Our study characterized the effects of stormwater discharges by continuously (30-min intervals) measuring salinity, temperature, tidal stage, and dissolved oxygen (DO) along an offshore eutrophication gradient prior to and following heavy rainfall at the beginning of the 1992 rainy season. The gradient included stations at a developed canal system (PP) on Big Pine Key, a seagrass meadow in a tidal channel (PC), a nearshore patch reef (PR), a bank reef at Looe Key National Marine Sanctuary (LK), and a blue water station (BW) approximately 9 km off of Big PIne Key. Water samples were collected at weekly intervals during this period to determine concentrations of total nitrogen (TN), ammonium (NH4+), nitrate plus nitrite NO3 plus NO2), total phosphorus (TP), total dissolved phosphorus (TDP), soluble reactive phosphorus (SRP), and chlorophyll a (chl a). Decreased salinity immediately followed the first major rainfall at Big Pine Key, which was followed by anoxia (DO <0.1 mg I−1), high concentrations of NH4+ (≈24 μM), TDP (≈1.5 μM), and chl a (≈20 μg I−1). Maximum concentration of TDP (≈0.30 μM) also followed the initial rainfall at the PC, PR, and LK stations. In contrast, NH4+ (≈4.0 μM) and chl a (0.45 μg I−1) lagged the rain event by 1–3 wk, depending on distance from shore. The highest and most variable concentrations of NH4+, TDP, and chl a occurred at PP, and all nutrient parameters correlated positively with rainfall. DO at all stations was positively correlated with tide and salinity and the lowest values occurred during low tide and low salinity (high rainfall) periods. Hypoxia (DO <2.5 mg I−1) was observed at all stations follwing the stormwater discharges, including the offshore bank reef station LK. Our study demonstrated that high frequency (daily) sampling is necessary to track the effects of episodic rainfall events on water quality and that such effects can be detected at considerable distances (12 km) from shore. The low levels of DO and high levels of nutrients and chl a in coastal waters of the Florida Keys demand that special precautions be exercised in the treatment and discharge of wastewaters and land-based runoff in order to preserve sensitive coral reef communities.


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Literature Cited

  1. Bell, P. R. F., 1992. Eutrophication and coral reefs—Some examples in the Great Barrier Reef lagoon. Water Research 26:553–568.CrossRefGoogle Scholar
  2. Bicki, T. J., R. B. Brown, M. E. Collins, R. S. Mansell, and D. F. Rothwell. 1984. Impact of on-site sewage disposal systems on surface and groundwater quality. Report to the Department of Health and Rehabilitative Services under contract #LC170. Soil Science Department, Institute of Food and Agricultural Services (IFAS), University of Florida, Gainesville, Florida.Google Scholar
  3. Boesch, D., N. E. Armstrong, C. F. D'Elia, N. G. Maynard, H. N. Paerl, and S. L. Williams, 1993. Deterioration of the Florida Bay ecosystem: An evaluation of the scientific evidence. Report to the Interagency Working Group on Florida Bay, Department of Interior, National Parks Service, Washington, D.C.Google Scholar
  4. Burnison, B. K., 1979. Modified dimethyl sulfoxide (DMSO) extraction for chlorophyll analysis of phytoplankton, Canadian Journal of Fisheries and Aquatic Science 37:729–733.CrossRefGoogle Scholar
  5. Cambridge, M. L., and A. J. McComb, 1984. The loss of seagrasses in Cockburn Sound, Western Australia. I. The time course and magnitude of seagrass decline in relation to industrial development. Aquatic Botany 20:229–243.CrossRefGoogle Scholar
  6. Corredor, J. E., J. Morrel, and A. Mendez, 1984. Dissolved nitrogen, phytoplankton biomass, and island mass effects in the northeastern Caribbean Sea. Caribean Journal of Science 20:129–137.Google Scholar
  7. D'Elia, C. F., P. A. Steudler, and N. Corwin, 1977. Determination of total N in aqueous samples using persulfate digestion. Limnology and Oceanography 22:760–764.Google Scholar
  8. Gordon, A. S., W. J. Cooper, and D. J. Schiedt, 1986. Denitrification in marl and peat sediments in the Florida Everglades. Applied Environmental Microbiology 52:987–991.Google Scholar
  9. Johannes, R. E., 1975. Pollution and degradation of coral reef communities, p. 13–51. In E. Wood and R. E. Johannes (eds.), Tropical Marine Pollution. Elsevier, New York.CrossRefGoogle Scholar
  10. Johannes, R. E., 1980. The ecological significance of the submarine discharge of groundwater. Marine Ecology Progress Series 3:365–373.CrossRefGoogle Scholar
  11. Johannes, R. E. and C. J. Hearn. 1985. The effect of submarine ground water discharge on nutrient and salinity regimes in a coastal lagoon off Perth, Western Australia.Estuarine, Coastal and Shelf Science 21:789–800.CrossRefGoogle Scholar
  12. Jokiel, P. L., C. L. Hunter, S. Taguchi, and L. Watarai. 1993. Ecological impact of a fresh-water “reef-kill” in Kaneohe Bay, Oahu, Hawaii. Coral Reefs 12:177–184.CrossRefGoogle Scholar
  13. Ketchum, B. H. 1967. Phytoplankton nutrients in estuaries, p. 329–335. In G. H. Lauff (ed.), Estuaries. American Association for the Advancement of Science, Washington, D.C.Google Scholar
  14. Lapointe, B. E. 1989. Macroalgal production and nutrient relations in oligotrophic areas of Florida Bay. Bulletin of Marine Science 44:312–323.Google Scholar
  15. Lapointe, B. E. and M. W. Clark. 1992. Watershed nutrient inputs and coastal eutrophication in the Florida Keys, USA. Estuaries 15:465–476.CrossRefGoogle Scholar
  16. Lapointe, B. E., W. R. Matzie, and M. Clark. 1993. Phosphorus inputs and eutrophication on the Florida Reef Tract, p. V15-V21. In R. Ginsberg (ed.), Proceedings of the Colloquium on Global Aspects of Coral Reefs: Health, Hazards, and History. University of Miami, Coral Gables, Florida.Google Scholar
  17. Lapointe, B. E., J. D. O'Connell, and G. S. Garrett. 1990. Nutrient couplings between on-site sewage disposal systems, groundwaters, and nearshore surface waters of the Florida Keys. Biochemistry 10:289–307.Google Scholar
  18. Lapointe, B. E. and N. P. Smith. 1987. A preliminary investigation of upwelling as a source of nutrients to Looe Key National Marine Sanctuary. National Ocean and Atmospheric Administration Technical Memorandum NOS MEMD 9, Washington, D.C.Google Scholar
  19. Lapointe, B. E., D. A. Tomasko, and W. R. Matzie. 1994. Eutrophication and trophic state classification of seagrass communities in the Florida Keys. Bulletin of Marine Science 54:696–717.Google Scholar
  20. Laws, E. A. and D. G. Redalje. 1979. Effect of sewage enrichment on the phytoplankton population of a subtropical estuary. Pacific Science 33:129–144.Google Scholar
  21. MacVicar, T. K. 1983. Rainfall averages and selected extremes for central and south Florida. South Florida Water Management Distrinct, Technical publication #83-2, West Palm Beach, Florida.Google Scholar
  22. Mallin, M. A., H. W. Paerl, J. Rudek, and P. W. Bates. 1993. Regulation of estuarine primary production by watershed rainfall and river flow. Marine Ecology Progress Series 93:199–203.CrossRefGoogle Scholar
  23. Marmer, H. A. 1954. Tides and sea level in the Gulf of Mexico. United States Fish and Wildlife Service Fisheries Bulletin 55:101–118.Google Scholar
  24. Marsh, J. A. 1977. Terrestrial inputs of nitrogen and phosphorus on fringing reefs of Guam. Proceedings of the Third International Coral Reef Symposium 1:331–336.Google Scholar
  25. McIvor, C. C., J. A. Ley, and R. D. Bjork. 1994. Changes in freshwater inflow from the Everglades to Florida Bay including effects on biota and biotic processes: A review, p. 117–146. In S. Davis and J. Ogden (eds.), Everglades, St. Lucie Press, Delray Beach, Florida.Google Scholar
  26. Mee, L. D. 1988. A definition of “critical eutrophication” in the marine environment. Revista de Biologia Tropical 36:159–161.Google Scholar
  27. Menzel, D. W. and N. Corwin. 1965. The measurement of total phosphorus in seawater based on the liberation of organically bound fractions by persulfate oxidation. Limnology and Oceanography 10:280–282.CrossRefGoogle Scholar
  28. Menzel, D. W. and J. P. Spaeth. 1962. Occurrence of ammonia in Sargasso Sea waters and in rain water at Bermuda. Limnology and Oceanography 7:159–162.Google Scholar
  29. Mitchell, R. 1974. Introduction to Environmental Microbiology. Prentice-Hall, Inc., Englewood Cliffs, New Jersey.Google Scholar
  30. National Oceanic and Atmospheric Administration. 1988. Results of a workshop on coral reef research and management in the Florida Keys: A blueprint for action. National Undersea Research Report 88-5, Washington, D.C.Google Scholar
  31. Odum, H. T. and R. F. Wilson. 1962. Further studies on reaeration and metabolism of Texas Bays, 1958–1960. Intitute of Marine Science Publications 8:23–55.Google Scholar
  32. Ogden, J. C., J. W. Porter, N. P. Smith, A. M. Szmant, W. C. Jaap, and D. Forcucci. 1994. A long-term interdisciplinary study of the Florida Keys seascape. Bulletin of Marine Science 54:1059–1071.Google Scholar
  33. Pastorok, R. A. and G. R. Bilyard. 1985. Effects of sewage pollution on coral reef communities. Marine Ecology Progress Series 21:175–189.CrossRefGoogle Scholar
  34. Paerl, H. W. 1985. Enhancement of marine primary production by nitrogen-enriched acid rain. Nature 316:747–749.CrossRefGoogle Scholar
  35. Porter, J. W. and O. W. Meier. 1992. Quantification of loss and change in Floridean reef coral populations. American Zoologist 32:625–640.Google Scholar
  36. Porter, J. W., O. W. Meier, J. I. Tougas, and S. K. Lewis. 1994. Modification of the South Florida hydroscape and its effect on coral reef survival in the Florida Keys. Bulletin of the Ecological Society of America 75[2: Part 2]:184.Google Scholar
  37. Richmond, R. H. 1993. Effects of coastal runoff on coral reproduction, p. P42-P46. In R. Ginsberg (ed.), Proceedings of the Colloquium on Global Aspects of Coral Reefs: Health, Hazards, and History. University of Miami, Coral Gables, Florida.Google Scholar
  38. Sakai, K. and M. Nishihira. 1991. Immediate effect of terrestrial runoff on a coral community near a river mouth in Okinawa. Galaxea 10:125–134.Google Scholar
  39. Slawk, G. and J. J. MacIsaak. 1972. Comparison of two automated ammonium methods in a region of coastal upwelling. Deep Sea Research 19:521–524.Google Scholar
  40. Smith, N. P. 1994. Long-term Gulf-to-Atlantic transport through tidal channels in the Florida Keys. Bulletin of Marine Science 54: 602–609.Google Scholar
  41. Smith, S. V., W. J. Kimmerer, E. A. Laws, R. E. Brock, and T. W. Walsh. 1981. Kaneohe Bay sewage diversion experiment: Perspectives on ecosystem response to nutritional perturbation. Pacific Science 35:279–397.Google Scholar
  42. Tomascik, T. and F. Sander. 1985. Effects of eutrophication on reef-building corals. I. Growth rate of the reef-building coral Montastrea annularis. Marine Biology 87:143–155.Google Scholar
  43. Tomascik, T. and F. Sander. 1987. Effects of eutrophication on reef-building corals: Reproduction of the reef-building coral Porites porites. Marine Biology 94:77–94.CrossRefGoogle Scholar
  44. Tomasko, D. A. and B. E. Lapointe. 1991. Productivity and biomass of Thalassia testudinum as related to water column nutrients and epiphyte levels: Field observations and experimental studies. Marine Ecology Progress Series 75:9–17.Google Scholar
  45. Urban, N. H., S. M. Davis, and N. G. Aumen. 1993. Fluctuations in sawgrass and cattail densities in Everglades Water Conservation area 2A under varying nutrient, hydrologic, and fire regimes. Aquatic Botany 46:203–223.CrossRefGoogle Scholar
  46. United States Environmental Protection Agency. 1992. Water Quality Protection Program for the Florida Keys National Marine Sanctuary: Phase I Report. United States Environmental Protection Agency, Atlanta, Georgia.Google Scholar
  47. United States Environmental Protection Agency. 1993. Water Quality Protection Program for the Florida Keys National Marine Sanctuary: Programe Document. April 1993. United States Environmental Protection Agency, Atlanta, Georgia.Google Scholar
  48. Valiela, I., J. Costa, K. Foreman, J. M. Teal, B. Howes, and D. Aubrey. 1990. Transport of groundwater-borne nutrients from watersheds and their effects on coastal waters. Biogeochemistry 10:177–198.CrossRefGoogle Scholar

Copyright information

© Estuarine Research Federation 1996

Authors and Affiliations

  • Brian E. Lapointe
    • 1
  • William R. Matzie
    • 1
  1. 1.Division of Marine Science Florida Keys ProgramHarbor Branch Oceanographic Institution, Inc.Big Pine Key

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