Fighting Invasive Species at Jean Lafitte

Image of research bending down from boardwalk toward plastic squares floating in plant-covered water

A park researcher checks the status of aquatic weevils that are helping to fight nonnative invasive species.

National Park Service

Quick Facts


A Call to Action
Action Item:
Follow the Flow
Year Accomplished:

Giant salvinia (Salvinia molesta), a floating aquatic fern native to the Amazon Basin, is one of the most formidable nonnative invasive species found at the Barataria Preserve, one of Jean Lafitte National Historical Park and Preserve's six sites. It multiplies rapidly and forms thick floating mats of vegetation that prevent sunlight from reaching the water below, affecting aquatic plant and animal life. Giant salvinia covers most preserve waterways for much of the year, a nuisance to fishers and boaters and a threat to the wetlands ecosystem.

The park is fighting back with science, education, and a salvinia-eating weevil. Park staff have developed a system to sample giant salvinia populations in the preserve, assembled laboratory resources to analyze samples, and created methods to measure bio-control agent populations. The bio-control agent is a tiny weevil which 20 years of research on three continents has shown only eats giant salvinia.

Two environmental stewards were hired in summer 2012 to focus on developing the giant salvinia bio-control effort. Their tasks included addressing natural resource management needs, creating educational materials for park interpreters, and involving park volunteers in the project. The stewards designed an education program for middle school students that was used at a preserve summer camp, produced weekly waterway accessibility updates for park staff and visitors, and developed interpretive guides about their project.

The stewards also explored preserve canals and bayous to scout canoe accessible routes and create maps, introduced weevils into selected preserve waterways, developed and implemented a program to monitor weevil populations and waterway coverage by giant salvinia, and trained park volunteers to assist in the effort to control giant salvinia throughout the preserve.