Seagrass fatalities in North Biscayne Bay, South Florida due to increases in nutrients and macroalgae in its environment


  • Andrea Carbonell American Heritage School (Plantation)
  • Leya Joykutty American Heritage School (Plantation)
  • Blake Velde



Biscayne Bay, Seagrass deaths, Seagrass fatalities, South Florida Bay, Algae blooms, Nutrient increases


Biscayne Bay is a subtropical estuary located in South Florida. It is a rich environment containing a multitude of organisms such as seagrass, sponges, and fish. The Biscayne Bay ecosystem is currently undergoing a drastic environmental decline due to seagrass fatalities throughout the area, specifically in North Biscayne Bay. This literature review pinpointed the causes and effects of these seagrass fatalities from analyzed research that has been completed on this subject. The research papers found for this review came from five databases: Google Scholar, the Biscayne Bay Task Force Database (HPI), Gale in Context, Gale Academic OneFile and JSTOR. A total of 245 papers were looked over and 18 articles were left to use for this review. From those papers, it was concluded that the most probable cause of the seagrass fatalities was the pollution runoff from metropolitan areas that stimulated nutrient overloads. These nutrient overloads are factors that cause algal blooms, which in turn cause these seagrass fatalities due to lack of sunlight and resources for photosynthesis. The lack of seagrass regulating the fragile Biscayne Bay environment is also causing an influx of fish deaths, which is bringing about a local economic decline in commercialized fishing. Without the properties of seagrass in Biscayne Bay, it can cause a more drastic environmental meltdown that may not be fixable.


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References or Bibliography

Alexander, J., & Solomon, C. (2005). The Role of Eutrophication in the Global Proliferation of Harmful Algal Blooms. Oceanography, 18(2).

Collado-Vides, L., Sweeney, P., & Buck, E. (2018, January). Macroalgae in Biscayne Bay: Different issues, Different causes, Different challenges. [PowerPoint slides]. HPI.

Used in background research

Cullen-Unsworth L, Jones B, Lilley R and Unsworth R (2018) Secret Gardens Under the Sea: What are Seagrass Meadows and Why are They Important?. Front. Young Minds. 6:2. doi: 10.3389/frym.2018.00002

Used in background research

Eldredge, L., Burgett, C., & Gumbleton, S. (2019, August). Biscayne Bay Aquatic Preserves [PowerPoint slides]. HPI.

Used in conclusion

Florida and Miami-Dade County Launch $20M Biscayne Bay Preservation Project. (2020, December 21). NBC Miami. Retrieved January 1, 2021, from

Used in conclusion.

Gimenez, C. A. (2019, February 5). Report on Seagrass Decline per Directive No. 171537. HPI. Retrieved December 23, 2020, from

Used in background research.

Irlandi, E., Orlando, B., & Cropper, W. (2004). SHORT-TERM EFFECTS OF NUTRIENT ADDITION ON GROWTH AND BIOMASS OF THALASSIA TESTUDINUM IN BISCAYNE BAY, FL. Florida Scientist, 67(1), 18-26. Retrieved December 23, 2020, from

Used in background research

Kelble, C. (2019, April). NOAA Biscayne Bay Water Quality Trends [PowerPoint slides]. HPI.

Used in conclusion. Explain correlation between nutrients & algal increases.

Lirman, D., Thyberg, T., Santos, R., Schopmeyer, S., Drury, C., Collado-Vides, L., . . . Serafy, J. (2014). SAV Communities of Western Biscayne Bay, Miami, Florida, USA: Human and Natural Drivers of Seagrass and Macroalgae Abundance and Distribution Along a Continuous Shoreline. Estuaries and Coasts, 37(5), 1243-1255. Retrieved December 23, 2020, from

Used in background research

McKay, B., & Mulvaney, K. (2001). A Review of Marine Major Ecological Disturbances. Endangered Species Update, 18(1), 14.

Used in conclusion

Miami-Dade County DERM. (2016, August 2). Evaluation of apparent seagrass die-off condition in Julia Tuttle Basin, North Biscayne Bay. HPI.

Used in data analysis. Figure 2, 3

Miami-Dade County - Environment - Biscayne Bay. (2014, February 18). Retrieved November 28, 2020, from

Explained what Biscayne Bay is & what organisms are located there. Used in Background Research and Proposal Presentation.

Millette, N.C., Kelble, C., Linhoss, A. et al. Using Spatial Variability in the Rate of Change of Chlorophyll a to Improve Water Quality Management in a Subtropical Oligotrophic Estuary. Estuaries and Coasts 42, 1792–1803 (2019).

Used in data analysis. Figure 8 & 9

Monaco, A. (., & Prouzet, P. (2015). Marine ecosystems: Diversity and functions. ISTE.

Background research

Mooney, Chris. "Scientists weigh causes and consequences of huge seagrass die-off in Florida Bay." Washington Post, 28 Apr. 2016. Gale In Context: Science, Accessed 31 Dec. 2020.

Used in background.

Society for Science and the Public (2019-20). International Science and Engineering Fair 2019-20: International Rules & Guidelines. Washington, DC: Society for Science and the Public.

Sweeney, P. (2019, July 15). State of Biscayne Bay Water Quality & Seagrass Habitat [PowerPoint slides]. HPI.

Used in background research and data analysis. Figure 1

Varona, G., Collado-Vides, L., Abdelrahman, O., Avila, C., & Murley, B. (2018, January). INCREASES IN MACROALGAE AND WATER QUALITY TRENDS ASSOCIATED WITH SEAGRASS LOSS IN NORTH BISCAYNE BAY [PowerPoint slides]. HPI.

Used in background research & data analysis

Figure 4, 5, 6, 7, 10, 11, 12



How to Cite

Carbonell, A., Joykutty, L., & Velde, B. (2021). Seagrass fatalities in North Biscayne Bay, South Florida due to increases in nutrients and macroalgae in its environment. Journal of Student Research, 10(3).



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