Will use of WHS™ result in increased water hyacinth in local waterways? Multiple barriers are employed with the WHS™ system design to prevent the release of hyacinth tissue and seeds into adjoining waterways. A benefit of using water hyacinth prior to discharge is that water quality is substantially improved, making the treated water less hospitable for water hyacinth growth. A laboratory study of hyacinth-based compost revealed that hyacinth seeds were not viable in the finished product. High temperatures associated with the compost process are likely responsible for the loss in seed viability.
Do introduced biological controls for the water hyacinth affect WHS™ performance? Water hyacinth is a prolific competitor for nutrients in open water, meaning that the same qualities that allow it to be a valuable plant for nutrient control cause it to be a nuisance in natural water bodies. Two species of weevil (Neochetina spp.) were introduced in the 1970’s to control water hyacinth plants, and these weevils can be found in Water Hyacinth Scrubbers. To enhance system performance by minimizing the effect of weevil predation on young plants, naturally occurring nematodes, a biological control for the weevils, are introduced in the WHS™. Unlike other water treatment alternatives, which use chemical pesticides to control unwanted species, periodic nematode introduction is the only pest control measure employed for the WHS™.
Does the WHS™ increase production of mosquitoes? Mosquito problems are not associated with WHS™ systems as a result of mosquito control programs that include introduction of mosquito fish populations Gambusia spp, into WHS™ units, and routine harvesting of hyacinth biomass.