The Role of Land Runoff in Algal Blooms in Southwest
Florida Estuaries and Coastal Waters
Larry E. Brand
University of Miami
Rosenstiel School of Marine and Atmospheric Science
Angela Compton Lee County FWRI
Cove Point Foundation SFWMD
Susan Fite NSF Lee County Env. Lab
NIH
Karenia brevis
1954-1963 1994-2002 Increase
Mean 36,000 474,200 13.2x
Mean of
monthly 34,100 618,200 18.1x
bins
A+B+C
Highest cell densities (Top 1%)
(million cells/L)
1954-1963 2.5
1994-2002 34.7
Nutrient Sources
• Upwelling • Agricultural fertilizer
• Nitrogen fixation • Soil erosion
• Sewage • Peat degradation
• Animal wastes • Phosphate mining
• Residential fertilizer
Rivers
Nonpoint source runoff
Groundwater
Reduced nutrient
assimilation capacity
• Disturbed terrestrial ecosystems
• Increased impervious surfaces
(increased runoff)
• Loss of wetlands
• Loss of seagrass
Turner et al. (2006)
1920 1940 1960 1980
March 7, 2007
May 26-27, 2007
October 21-26, 2007
October 21-26, 2007
October 21-26, 2007
Eukaryotic Algae Cyanobacteria
Longer Food Chains
Specific Toxins
BMAA
BMAA
Beta-N-methylamino-L-alanine
Neurodegenerative diseases
• Alzheimer's disease
• Parkinson's disease
• Amyotrophic Lateral Sclerosis