Estuaries and Coasts

, Volume 42, Issue 3, pp 719–730 | Cite as

Determining the Sources of Macroalgae During Beach Stranding Events from Species Composition, Stable Isotope Analysis, and Laboratory Experiments

  • E. C. MilbrandtEmail author
  • L. Reidenbach
  • Michael Parsons


Large accumulations of stranded macroalgae on the beaches of Sanibel Island from 2004 to 2007 were unusual and thought to be driven by high rainfall and river flows stemming from a high frequency of hurricanes. The southwest Florida shelf was thought to be isolated from far-field effects such as high river flows and urbanization but field- and laboratory-based studies suggest that nitrogen enrichment, fragmentation, and species composition of macroalgal communities on the shelf and in the estuary contribute to beach stranding events. Macroalgae were sampled using a belt transect method to determine species distribution and abundance. Macroalgae were abundant (1) in the lower estuary with abundant seagrass and (2) on limestone outcroppings in the Gulf of Mexico. An MDS analysis of the quadrat samples indicated two distinct macroalgal community types, a “Sound” assemblage around Pine Island Sound and a “Gulf” assemblage, associated with a live bottom and patch reef in the Gulf of Mexico. Peak abundances for the two community types differed with the Gulf having peak abundances from July to November, while peak abundances in the Sound occurred from January to July. Sound macroalgal tissue had significantly enriched δ15N compared to Gulf tissue when all species were combined and in five of six species collected at both locations suggesting that stable isotope analysis could be useful in combination with species composition in determining the source of macroalgae during stranding events. In addition, a laboratory study was conducted on four species that were sampled and frequently collected as a result of stranding events. Laboratory growth experiments demonstrated the potential for three of four common species (Solieria filiformis, Gracilaria tikvahiae, Agardhiella subulata) to fragment and grow significantly more under elevated nitrate conditions.


Sanibel Continental shelf Fragmentation Nitrogen Fragmentation 



This was supported by a grant from the City of Sanibel, Lee County, and the West Coast Inland Navigation District to E. Milbrandt. Several other Co-PIs from Florida Gulf Coast University contributed to the overall effort including A.N. Loh, E. Everham, and D. Fugate. This is contribution 0034 from the Sanibel-Captiva Conservation Foundation Marine Laboratory. The authors would like to thank an anonymous reviewer for their feedback on an earlier draft and would like to thank the Associate Editor, Nancy L. Jackson.


  1. Bach, S.D., and M.N. Josselyn. 1978. Mass blooms of the alga Cladophora in Bermuda. Marine Pollution Bulletin 9 (2): 34–37.Google Scholar
  2. Barnes, T.K., A.K. Volety, K. Chartier, F.J. Mazzotti, and L. Pearlstine. 2007. A habitat suitability index model for the eastern oyster (Crassostrea virginica), a tool for restoration of the Caloosahatchee estuary, Florida. Journal of Shellfish Research 26 (4): 949–959.CrossRefGoogle Scholar
  3. Bell, S.S., and M.O. Hall. 1997. Drift macroalgal abundance in seagrass beds: Investigating large-scale associations with physical and biotic attributes. Marine Ecology Progress Series 147: 277–283.CrossRefGoogle Scholar
  4. Booth, A.C., L.E Soderqvist, T.M. Knight. 2016. Effects of variations in flow characteristics through W.P. Franklin Lock and Dam on downstream water quality in the Caloosahatchee River Estuary and in McIntyre Creek in the J.N. “Ding” Darling National Wildlife Refuge, southern Florida, 2010–13. Scientific Investigations Report 2016-5033, United States Geological Survey, 33 p.Google Scholar
  5. Brand, L.E., and A. Compton. 2007. Long-term increase in Karenia brevis abundance along the southwest Florida coast. Harmful Algae 7: 232–252.CrossRefGoogle Scholar
  6. Brooks, R.A., C.N. Purdy, S.S. Bell, and K.L. Sulak. 2006. The benthic community of the eastern US continental shelf: A literature synopsis of benthic faunal resources. Coastal Shelf Research 26 (6): 804–818.CrossRefGoogle Scholar
  7. Carpenter, E. and D. Capone. 1983. Nitrogen in the marine environment. Academic Press, 900 pp.Google Scholar
  8. Clarke, R.M., and K.R. Warwick. 1998. Taxonomic distinctness and environmental assessment. Journal of Applied Ecology 35: 532–543.CrossRefGoogle Scholar
  9. Crossett, K. M., T. J. Culliton, P. C. Wiley, and T. R. Goodspeed. 2004. Population trends along the coastal United States: 1980–2008. NOAA/National Ocean Service.
  10. Dawes, C.J. 1969. The hourglass cruises: Benthic marine algae. Florida Marine Research Laboratory 1: 1–45.Google Scholar
  11. Dawes, C.J. 2004. Drift Algae in the Charlotte Harbor area. Report to the South Florida Water Management District. 16 pp.Google Scholar
  12. Dawes and Mathieson, 2008. The seaweeds of Florida. University Press of Florida, 591 pp.Google Scholar
  13. Dawes, C.J., A.C. Mathieson, and D.P. Cheney. 1974. Ecological studies of floridian Eucheuma (Rhodophyta, Gigartinales), Eucheuma (Rhodophyta, Gigartinales). I. Seasonal growth and reproduction. Bulletin of Marine Science 24 (2): 235–273.Google Scholar
  14. Doering, P.H., and R.H. Chamberlain. 1999. Water quality and source of freshwater discharge to the Caloosahatchee estuary, Florida. Journal of the American Water Resources Association 35 (4): 793–806.CrossRefGoogle Scholar
  15. Duarte, C.M. 1995. Submerged aquatic vegetation in relation to different nutrient regimes. Ophelia 41 (1): 87–112.CrossRefGoogle Scholar
  16. Dugan, J.E., D.M. Hubbard, M.D. McCrary, and M.O. Pierson. 2003. The response of macrofauna communities and shorebirds to macrophyte wrack subsidies on exposed sandy beaches of southern California. Estuarine, Coastal, and Shelf Science 58: 25–40.CrossRefGoogle Scholar
  17. Fourqurean, J.W., A. Willsie, C.D. Rose, and L.M. Rutten. 2001. Spatial and temporal pattern in seagrass community composition and productivity in south Florida. Marine Biology 138 (2): 341–354.CrossRefGoogle Scholar
  18. Fry, B. 2006. Stable Isotope Ecology. Springer, 308 pp.Google Scholar
  19. Haas, F. 1940. Ecological observations on the common mollusks of Sanibel Island, Florida. American Midland Naturalist 24 (2): 369–378.CrossRefGoogle Scholar
  20. Hine, A.C., and S.D. Locker 2009. The Florida Gulf of Mexico continental shelf—great contrasts and significant transitions, in, Holmes, C.E., ed., Gulf of Mexico—Geology: Fisheries Volume Bulletin 89, Harte Institute, Texas A&M University Press.Google Scholar
  21. Johnson, K.S., and L.J. Coletti. 2002. In situ ultraviolet spectrophotometry for high resolution and long-term monitoring of nitrate, bromide and bisulfide in the ocean. Deep-Sea Research 49 (7): 1291–1305.CrossRefGoogle Scholar
  22. Joyce, E.A., and J. Williams. 1969. Rationale and pertinent data. Memoirs of the Hourglass Cruises 1: 1–50.Google Scholar
  23. Lapointe, B.E., and B.J. Bedford. 2007. Drift rhodophyte blooms emerge in Lee County, Florida, USA: Evidence of escalating coastal eutrophication. Harmful Algae 6 (3): 421–437.CrossRefGoogle Scholar
  24. Lapointe, R.E., and J.B. Ryther. 1978. Some aspects of the growth and yield of Gracilaria tiltoahlae in culture. Aquaculture 15 (3): 185–193.CrossRefGoogle Scholar
  25. Lee County Visitor and Convention Bureau. 2017. Annual visitor profile and occupancy analysis (pp. 54). Fort Myers: Lee County Visitor and Convention Bureau.Google Scholar
  26. LeeVCB 2006. Statistics for Lee County, FL, beaches, a 20 year summary, 11 pp.Google Scholar
  27. Lobban, C.S., and M.J. Wynne. 1981. The biology of seaweeds. Oxford: Blackwell Scientific Publications.Google Scholar
  28. Loh, A.N., L.E. Brand, D.W. Ceilley, M. Charette, L. Coen, E.M. Everham III, D.C. Fugate, Raymond E. Grizzle, E.C. Milbrandt, B.M. Riegl, G. Foster, K. Provost, L.L. Tomasello, P. Henderson, C. Breier, Q. Liu, T. Watson, and M.L. Parsons. 2011. Bioavailability of nutrients and linkages to red drift algae. Technical Report to the City of Sanibel and Lee County. 133 pp.Google Scholar
  29. Maze, J., P. Morand, and P. Potoky. 1993. Stabilisation of ‘Green tides’ Ulva by a method of composting with a view to pollution limitation. Journal of Applied Phycology 5: 183.Google Scholar
  30. McGlathery, K.J. 1995. Nutrient and grazing influences on a subtropical seagrass community. Marine Ecology Progress Series 122: 239–252.Google Scholar
  31. McPherson, B.F., and R.L. Miller. 1987. The vertical attenuation of light in Charlotte Harbor, a shallow, subtropical estuary, south-western Florida. Estuarine, Coastal and Shelf Science 25 (6): 721–737.Google Scholar
  32. Milbrandt, E.C., and J. Siwicke. 2016. Leaf growth rates (Thalassia testudinum, Banks ex Koning) as an indicator of seagrass responses to regulated freshwater discharges. Gulf of Mexico Science 2016 (1): 38–46.Google Scholar
  33. Milbrandt, E.C, R.D. Bartleson, A. Martignette, M. Thompson, J. Siwicke. 2016. Evaluating light attenuation and low salinity periods in the lower Caloosahatchee estuary using RECON (River, Estuary, and Coastal Observing Network). CHNEP Special Issue, Florida Scientist 79: 109–124.Google Scholar
  34. Munguia, P. 2004. Successional patterns on pen shell communities at local and regional scales. Journal of Animal Ecology 73 (1): 64–74.CrossRefGoogle Scholar
  35. Perry, L.M. 1936. Pen shells on Sanibel, a marine tenement. Science 84 (2172): 156–157.CrossRefGoogle Scholar
  36. Posey, M.H., T.D. Alphin, S. Banner, F. Vose, and W. Lindberg. 1998. Temporal variability, diversity and guild structure of a benthic community in the northeastern Gulf of Mexico. Bulletin of Marine Science 63: 143–155.Google Scholar
  37. Rabalais, N.N., W.J. Wiseman Jr., and R.E. Turner. 1994. Comparison of continuous records of near-bottom dissolved oxygen from the hypoxia zone along the Louisiana coast. Estuaries 17 (4): 850–861.CrossRefGoogle Scholar
  38. Reigl, B.M., R.P. Moyer, L.J. Morris, R.W. Virnstein, and S.J. Purkis. 2005. Distribution and seasonal biomass of drift macroalgae in the Indian River Lagoon (Florida, USA) estimated with acoustic seafloor classification (QTCView, Echoplus). Journal of Experimental Marine Biology and Eoclogy 326 (1): 89–104.CrossRefGoogle Scholar
  39. Sassi, R., M.B.B. Kutner, and G.F. Moura. 1988. Studies on the decomposition of drift seaweed from the northeast Brazilian coastal reefs. Hydrobiologia 157 (2): 187–192.Google Scholar
  40. Scanlon, K. M. 1999. Geology of shelf-edge habitats of the West Florida Shelf. Fact Sheet 109–99, U.S. Geological Survey.Google Scholar
  41. SFWMD. 2009. Caloosahatchee River watershed protection plan, 276 pp.Google Scholar
  42. Tolley, S.G., and A.K. Volety. 2005. The role of oysters in habitat use of oyster reefs by resident fishes and decapod crustaceans. Journal of Shellfish Research 24: 1007–1012.CrossRefGoogle Scholar
  43. Valentine, J.F., K.L. Heck Jr., K.D. Kirsch, D. Webb. 2000. Role of sea urchin Lytechinus variegatus grazing in regulating subtropical turtlegrass Thalassia testudinum meadows in the Florida Keys (USA). Marine Ecology Progress Series 200: 213–228.Google Scholar
  44. Valiela, I., J. McClelland, J. Hauxwell, P.J. Behr, D. Herh, and K. Foreman. 1997. Macroalgal blooms in shallow estuaries: Controls and ecophysiological and ecosystem consequences. Limnology and Oceanography 42 (5part2): 1105–1118.CrossRefGoogle Scholar
  45. Virnstein, R.W., and R.K. Howard. 1987. Motile epifauna of marine macrophytes in the Indian River Lagoon, Florida II. Comparisons between drift algae and three species of seagrasses. Bulletin of Marine Science 41: 13–26.Google Scholar
  46. Volety, A.K., M. Savarese, S.G. Tolley, W.S. Arnold, P. Sime, P. Goodman, R.H. Chamberlain, and P.H. Doering. 2009. Eastern oysters (Crassostea virginica) as an indicator for restoration of Everglades Ecosystems. Ecological Indicators 9S: 120–136.CrossRefGoogle Scholar
  47. Weisberg, R. H., Y. Liu, D.A. Mayer. 2009. West Florida Shelf mean circulation observed with long-term moorings. Geophysical Research Letters 36(L19610).Google Scholar
  48. Xia, M., P.M. Craig, B. Schaeffer, A. Stoddard, Z. Liu, M. Peng, H. Zhang, C.M. Wallen, N. Bailey, and J. Mandrup-Poulson. 2010. The influence of physical forcing on bottom-water dissolved oxygen within the Caloosahatchee River Estuary, FL. Journal of Environmental Engineering 136 (10): 1032–1034.CrossRefGoogle Scholar

Copyright information

© Coastal and Estuarine Research Federation 2018

Authors and Affiliations

  1. 1.Marine LaboratorySanibel-Captiva Conservation FoundationSanibelUSA
  2. 2.Stony Brook UniversityStony BrookUSA
  3. 3.Florida Gulf Coast UniversityFort MyersUSA

Personalised recommendations