Aquatic Plant Management Program Enhancements
The FWC is committed to implementing a variety of enhancements to the Agency’s Aquatic Plant Management Program. Some of these improvements include exploring ways to better integrate and increase the strategic use of mechanical aquatic plant harvesting and creating habitat management plans to guide efforts for individual lakes.
Mechanical harvesting refers to the use of machinery to remove, convey and transport aquatic plants and associated organic material to in-lake or upland disposal sites. Mechanical shredding involves machinery designed to cut and shred aquatic plants into much smaller pieces allowing them to sink to the bottom of the waterbody. Mechanical controls range from small cutting boats to 90-foot long harvesters, and from track hoes and draglines stationed on shore or mounted on barges that lift plants and debris out of the water.
Mechanical harvesters are one method of controlling nuisance and invasive vegetation. One advantage of mechanical removal is there are no restrictions on water use following a treatment as there sometimes are with chemical treatment methods. Mechanical harvesters do increase water turbidity, but that is a temporary impact. While some small fish, amphibians, reptiles and invertebrates are removed as unintended by-catch, there is no evidence this will significantly affect over-all populations. Removal of the plant biomass prevents its eventual decay and settling to the bottom, helping to reduce sedimentation in the lake. Also, there is some level of nutrient removal with harvesting too, because the nitrogen and phosphorous that is bound up in the plant is removed from the water body.
However, mechanical harvesters alone cannot keep pace with the exponential growth of invasive aquatic plants in Florida waters. Resource managers in Florida and throughout the U.S. rely on an integrated approach to control invasive plants including herbicides, biological agents such as grass carp and sometimes even manual removal such as hand pulling.