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Florida’s Floating Islands

By Jackson Jablonski, agronomy master’s student with UF/IFAS Center for Aquatic and Invasive Plants (CAIP) 

In 1937, a lake in north-central Florida burst into a local newspaper headline with the news of an amazing new tourist destination known as the “Lake of a Thousand Floating Islands” (or more often known as Orange Lake).

Just south of Gainesville, Florida, Orange Lake was known to form “floating islands” that drew in tourists from all around the state to visit this natural wonder. A small economy formed around this destination; people came to see the massive floating mats of vegetation that sailed mysteriously around the lake using trees as sails. Soon floating diners and tour experiences were featured on the lake, the islands were even published in Robert Ripley’s ‘Ripley’s Believe it or Not’.

Today, the floating islands of Orange Lake are just as magnificent as they used to be. While it’s not one of Florida’s thrilling theme parks, they still bring in visitors from across the country to see the wildlife and natural areas.

The terminology for these floating mats of vegetation can vary but is typically considered to be in two categories: tussocks or floating islands. Tussocks are what you might often see in Florida lakes, they are rafts of floating vegetation that form from herbaceous plants growing on top of one another. Aquatic floating plants like waterhyacinth, water lettuce, and frog’s bit can make up tussocks, but sometimes they form from emergent plants like pennywort, smartweed, and Cuban bulrush. Wind and wave action can break free these emergent plants from the shoreline, causing them to travel away from the land and provide a place for other emergent plants to colonize.

Floating Islands are like tussocks but differ in how they are formed. These floating islands form from peat, moss, and decomposing vegetation that comes up from the lake bottom during drastic changes in water levels. The organic material can build up to two to three feet thick, supporting even trees to grow and flourish.

Sometimes these tussocks and floating islands can be problematic. Heavy winds from storms and hurricanes can move them around and cause them to crash into the shoreline, breaking docks and impeding marine navigation. These floating islands also impacted the area’s fish industry as far back as 1950, an article published in March 1950 discussed floating islands and their impact on a local fish camp.

The management options available for these islands now are much more varied than they used to be. Tussocks can be managed by way of chemical control, allowing the mats to sink to the bottom of the lake and decompose. However, floating islands can be more challenging, requiring a wide array of machinery to chunk the island apart and haul it out and away from the water. All lake management should be undertaken with consideration for the people, plants, and animals that utilize it to survive.

 

More information:

Photos belong to the Florida State Archives/Florida Memory, Bill Mosher, and Bruce Ackerman (The Gainesville Sun)

This blog post was written by Jackson Jablonski, agronomy master’s student with UF/IFAS CAIP. Questions or comments can be sent to the UF/IFAS CAIP communications manager at caip@ifas.ufl.edu.

Follow UF/IFAS CAIP on social media at @ufifascaip. Read more blogs like this one on the UF/IFAS CAIP blog.

UF/IFAS Center for Aquatic and Invasive Plants. Turning Science Into Solutions.