According to the Ohio Department of Natural Resource’s Ohio Field Guide to Aquatic Invasive Species, Hydrilla is “a submerged aquatic perennial that could be considered nature’s “perfect weed.” It comes in two forms, dioecious and monoecious.” Leaves are pointed with white flowers.
Some methods of controlling this plant, according to the Texas A&M AgriLife Extension, include: Physical removal, creation of an algal bloom, the use of dyes, the use of grass carp, and the use of herbicides.
The North Carolina Sea Grant recommends inspecting boats and disposing of all plant matter, including fragments, away from water. Weeding is “discouraged” because of Hydrilla’s fragmentation.
According to the ODNR Field Guide, Hydrilla clogs water with its mats, causing problems with irrigation, commercial activities and recreational activities. It also prevents the growth of native plants by blocking sunlight. In addition, “as the mats die and decay, bacteria deplete oxygen from the water, impacting fish and other aquatic organisms.”