Effects of Water Hyacinth Management on Fish Populations
Abstract
Invasive water hyacinth (Eichhornia crassipes) creates significant economic and ecological problems in Florida. Removal of this invader cost an estimated $4.19 million in the 2020 fiscal year. Water hyacinth has also been shown to alter water quality and chemistry and reduce fish populations. Current management strategies involve manual removal and the application of herbicide. New methods, including biological control, are being investigated to improve the efficiency of current management methods. Questions about the effects of these novel management strategies have emerged, including the response of fish populations to the new treatments. To answer these questions, we set up mesocosms in collaboration with the USDA Invasive Plant Research Lab and stocked them with locally caught Eastern Mosquitofish (Gambusia holbrooki). The mesocosms were sampled at least four times per year from 2020 to 2022, using minnow traps to assess fish populations. Treatments included control mesocosms without water hyacinth, an unmanaged mesocosm with water hyacinth, and mesocosms managed via biological and chemical control. Insecticide was used to isolate the effects of biological control. Our results suggest fish populations were highest when water hyacinth was not present. We also found populations were intermediate in the managed mesocosms with a moderate density of water hyacinth. Populations were lowest with a high density of water hyacinth and no management. However, as long as management is conducted, fish populations continue to thrive in the presence of invasive water hyacinth, although to a lesser degree than in un-invaded habitats.
Faculty Sponsors
Dr. J. Matthew Hoch
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-6-2022 12:00 PM
End Date
4-7-2022 5:00 PM
Effects of Water Hyacinth Management on Fish Populations
Alvin Sherman Library
Invasive water hyacinth (Eichhornia crassipes) creates significant economic and ecological problems in Florida. Removal of this invader cost an estimated $4.19 million in the 2020 fiscal year. Water hyacinth has also been shown to alter water quality and chemistry and reduce fish populations. Current management strategies involve manual removal and the application of herbicide. New methods, including biological control, are being investigated to improve the efficiency of current management methods. Questions about the effects of these novel management strategies have emerged, including the response of fish populations to the new treatments. To answer these questions, we set up mesocosms in collaboration with the USDA Invasive Plant Research Lab and stocked them with locally caught Eastern Mosquitofish (Gambusia holbrooki). The mesocosms were sampled at least four times per year from 2020 to 2022, using minnow traps to assess fish populations. Treatments included control mesocosms without water hyacinth, an unmanaged mesocosm with water hyacinth, and mesocosms managed via biological and chemical control. Insecticide was used to isolate the effects of biological control. Our results suggest fish populations were highest when water hyacinth was not present. We also found populations were intermediate in the managed mesocosms with a moderate density of water hyacinth. Populations were lowest with a high density of water hyacinth and no management. However, as long as management is conducted, fish populations continue to thrive in the presence of invasive water hyacinth, although to a lesser degree than in un-invaded habitats.
