Michael Massimi, BTNEP’s invasive species coordinator, explained on one such trip that invasives like elephant ears, hydrilla and water hyacinth don’t just out-compete native plants in the bayou, like arrowhead (known locally as “duck potato,” because it’s a favorite food of ducks), but, “They’re actually modifying the habitat,” Massimi says. “For example, elephant ears can tolerate growing in standing water, so they grow out from the banks and shoot up their stems, which collect sediment close to the bank, narrowing the stream, and keep growing out farther unless you dredge them.” And, unlike what it replaced, elephant ears provide no food for bayou inhabitants.
Hydrilla presents its own set of problems, Massimi says. It can grow in great mats that cover big sections of the water surface. “It makes fishing impossible and impedes recreational uses. If it’s too thick you can’t even get a boat through it. And if we have a particularly dry summer,” he says, “the water flow slows down, allowing more sunlight to penetrate, promoting growth of hydrilla. The water backs up and you get high water events near the headwaters, and saltwater intrusion from the Gulf; since freshwater can’t move down, saltwater moves up.”
St. Pé, a seventh-generation resident like many others who live among the bayous of southeastern Louisiana, adds that this project is an important first step, but much more must be done to restore the wetlands.
“We need to harvest sediment from the bottom of the river and pump it out to build back what we lost and then sustain that with freshwater diversions,” he says. “We need to build new land. We need to get land between us and the massive storm surges we get from these hurricanes. People have always been concerned about hurricanes, but they’re deathly afraid of them now.”