Project Background
Caddo Lake, located in northeast Texas, is the oldest public lake in the state, created by natural phenomena over 200 years ago. Its shorelines are shared with Louisiana and it is home to one of the most spectacular bald cypress forests in the southern United States. Due to its shallow depth, high nutrient content, and relatively stable water level, the lake has become a rich ecosystem capable of supporting a diverse array of life. Unfortunately, this also makes it a perfect environment for invasive species to flourish. For decades, navigation on the lake has been severely hindered by water hyacinth, and in the past 15 years, a rooted invasive known as hydrilla has only added to the problem. In addition to limiting boat access to major portions of the lake, these invasives can all but eliminate the natural vegetation in an area. This is possible due to the lack of having no natural enemies in these new areas. Things such as diseases, insects, and sources of other environmental stresses on the plant that keep their growth limited in their native habitats do not exist in areas where they have become invasive. Such is the case with the newest invasive plant making its presence known on the lake, giant salvinia (Salvinia molesta). This free-floating aquatic fern brought in from Brazil by the water garden industry is thought to have been first introduced to the lake in 2006. The plant exhibits very rapid growth and is capable of doubling its biomass within a week given favorable growing conditions. By 2006, it was estimated that roughly 2 acres of the lake were infested, but in 2008, that estimate grew to nearly 1000 acres. The thick mats of vegetation that are established through its excessive and continual growth effectively shut off sunlight to the water below and can deplete dissolved oxygen to levels that threaten aquatic life below the surface. To date, control efforts have yielded only moderate success due to its aggressive growth. As a result of the giant salvinia infestation and the myriad of other invasive species, the Lake itself is regarded by many as being one of Texas' most threatened ecosystems.
This potential loss of one of Texas' most unique ecosystems has not gone unnoticed. Through collaboration between Texas A&M AgriLife Research and Texas A&M AgriLife Extension Service through the Texas Water Resources Institute, the Center for Invasive Species Eradication (CISE) at Texas A&M University has been established with the aim of directing initiatives involving research, demonstrations, educational programs, and direct treatment activities with goals of controlling and removing invasive plant species from threatened Texas ecosystems. Funded through the USDA Natural Resources Conservation Service (NRCS), the Center will be used as a resource for organizations wishing to institute invasive plant species control programs throughout the state. Practical solutions for controlling existing invasive species infestations and methods to prevent further infestations from becoming established in other areas of the state will be evaluated and employed. The first of these programs is the Caddo Lake Giant Salvinia Eradication project, which is refining and promoting management strategies to control and eradicate giant salvinia.
References:
Tompkins, Shannon. "No Room to Grow: Going green isn't always for the best at Caddo Lake." The Houston Chronicle. 19 December 2009. Accessed 16 August 2010. (view article)
Wythe, Kathy. "Synergistic eradication: Center's first project tackles invasive plant at treasured lake." txH20: A Publication of the Texas Water Resources Institute 6.1 (2010): 4-5. (view article)