CBL helps Louisiana understand invasive nature of water hyacinth

October 12, 2015
Hyacinth invasion. Photo courtesy of Ted D. Center, USDA ARS.

CBL Research Professor Dr. Lisa Wainger is examining both the environmental and economic costs and benefits of fighting one of the southern Louisiana waterways’ most troublesome invasive species: water hyacinth.

In the 1880s, a South American plant called the water hyacinth was brought to the United States as a gift, but it has wreaked havoc on Louisiana’s rivers and inlets ever since.  With no native predators to keep it in check, it took over waterways entirely, forming thick green mats on the surface.  The plant uses up oxygen fish and other aquatic organisms need to breathe and makes water activities such as boating and fishing impossible.

Several methods have been used to keep this pest at bay, including reducing the fertilizer runoff that encourages its growth, using weed-killing herbicides, and bringing in its South American predator, the water hyacinth weevil.  These control efforts are expensive, but letting the invader spread is costly to ecological health and human quality of life.

Computer modeling image by Lisa Wainger.

Wainger is compiling information on the water hyacinth’s impacts and will use a computer modeling system to simulate what its spread would have been without treatment.  Through environmental economic analysis, Wainger will put a dollar value on the plant’s impacts on people to figure out which is greater — the price of controlling the hyacinth, or the ultimate cost of letting it spread.  Wainger is also locating places where management efforts are most cost-effective.

Wainger’s economic analysis of water hyacinth control is similar to many of her other research projects that have the primary goal of helping environmental managers target their efforts and spend restoration dollars where they get the most “bang for their buck.” Ultimately her work will promote ecological health and demonstrate how environmental management can bolster economies and human well-being.