Eutrophication in the Everglades

historic conditions:

• 4 million acres of Everglades marshes south of Lake Okeechobee
• sheet of water flow south (Pa-hay-okee or Grassy River)
• 40 miles wide x 1 foot deep
• saw grass (Cladium jamaicensis) predominant (70%) marsh plant

development within the past century:

• 1881 campaign to reclaim the Everglades for civilization
• started 1912 Tamiami Trail across the Everglades
  • disrupted natural water flow
• 1926 & 1928 hurricanes flooded Lake Okeechobee communities
• Hoover Dike, channelized water flow
• agriculture (primarily sugar cane) - 500,000 acres
  • canals, dry land, fertilizers
• Central and South Florida Project for Flood Control & Other Purposes
  • 103 mile long Kissammee River (meander) 56 mile C-38 canal
  • 1,400 miles of canals, levees, spillways & pumping stations
• population growth
  • 4.5 million people using Biscayne aquifer
• drought (1970's & 1980's)

current conditions:

• 2 million acres in natural state
• 10% historic wading bird populations
• eutrophication & fish kills
• soil loss (1 inch per year) 6 feet in 70 years
• fires
• salt water intrusion (marshes, aquifer, bays)
• displacement of saw grass by cattails and melaleuca (Melaleuca quinquenervia)

problems & solutions:

• melaleuca displacing native vegetation
  • natural controls ?
• disrupted hydrologic regime (volume, timing, locations)
  • increase flow toward natural conditions
• water quality (excess P)
  • storm water & surface water runoff treatment areas
  • cattail marsh buffers between developments and Everglades
• mercury bioaccumulation
  • natural or anthropogenic ?