Why is hydrilla a problem in Florida lakes and other waters?
Hydrilla verticillata is an invisible menace, invisible that is until it fills the lake or river that it infests, “topping out” at the surface. Hydrilla can grow an inch a day. When hydrilla invades, ecologically-important native submersed plants such as pondweeds (Potamogeton spp.), tapegrass (Vallisneria americana) and coontail (Ceratophyllum demersum) are shaded out by hydrilla’s thick mats, or are simply outcompeted, and eliminated (van Dijk 1985). Millions of dollars are spent each year on herbicides and mechanical harvesters in Florida alone in an effort to place hydrilla under “maintenance control.” Hydrilla verticillata greatly slows water flow and clogs irrigation and flood-control canals; in Florida, large mats of fragments collect at culverts and clog essential water control pumping stations. Hydrilla seriously interferes with boating, both recreational and commercial, and prevents swimming and fishing; major infestations limit sportfish weight and size (Colle & Shireman 198
Hydrilla verticillata is an invisible menace, invisible that is until it fills the lake or river that it infests, “topping out” at the surface. Hydrilla can grow an inch a day. When hydrilla invades, ecologically-important native submersed plants such as pondweeds (Potamogeton spp.), tapegrass (Vallisneria americana) and coontail (Ceratophyllum demersum) are shaded out by hydrilla’s thick mats, or are simply outcompeted, and eliminated (van Dijk 1985). Millions of dollars are spent each year on herbicides and mechanical harvesters in Florida alone in an effort to place hydrilla under “maintenance control.” Hydrilla verticillata greatly slows water flow and clogs irrigation and flood-control canals; in Florida, large mats of fragments collect at culverts and clog essential water control pumping stations. Hydrilla seriously interferes with boating, both recreational and commercial, and prevents swimming and fishing; major infestations limit sportfish weight and size (Colle & Shireman 198
