Most anglers know that Asian carp are harming this nation’s fisheries, from the Upper Midwest down to the Gulf Coast and eastward through the Ohio River watershed.
What many do not realize, however, is that other exotics also are doing severe damage. They don’t receive as much publicity because their range is more limited.
But in Louisiana, the nutria, a large rodent, is devouring the wetlands, destroying spawning and nursery habitat for a multitude of important sport fisheries. In fact, the state estimates that damage at any given time is about 46,000 acres, as about 5 million of the web-footed animals with large, orange teeth feed on the roots and stalks of aquatic plants.
Additionally, the giant apple snail also is taking a giant bite out of the wetlands. They’ve been banned from the state since 2012, but that was too late to keep them from becoming a destructive force, courtesy of irresponsible hobbyists who dumped their aquariums into waterways.
“They eat a ton of plant material, anything they can get their tiny little mouths on,” said Michael Massimi of the Barataria-Terrebonne National Estuary Program. “You are converting a water body from one dominated by plants to one dominated by algae.”
Asian carp, tiger prawns, water hyacinth, and giant salvinia also are among the exotic species doing damage to Louisiana’s coastal system.
Some limited good news is that the state’s nutria control plan, implemented in 2002, has lessened the impact of these furbearers, which were imported during the 1930s and promoted as a way to combat water hyacinth and other invasive plants during the 1940s.
Still the cumulative effect of these invaders is significant for an ecosystem already under siege. First came decades of habitat degradation and mismanagement, most of it originating from development and water diversions. These actions accelerated erosion and saltwater intrusion, which are crumbling away the equivalent of a football field every hour.
Then came the Deepwater Horizon oil spill and its aftermath, which added to the peril of an ecosystem that is critical for sustaining the food web of the Gulf of Mexico.
Fortunately, the spill also provided impetus for passage of the RESTORE Act, which provides a rare opportunity to restore and enhance the Delta and its wetlands. Guiding that restoration is a multi-state, multi-agency group known as the Gulf Coast Ecosystem Restoration Council.
And a coalition known as Vanishing Paradise is working to make sure that Council members remember the importance of habitat restoration, which can drive and support economic recovery.
“The people, business, communities, and economy of this region are undeniably reliant upon a healthy and productive Gulf, and ecosystem restoration should be the top priority,” said spokesman Ben Weber.
Sadly, passing legislation and creating coalitions will do little to counter the damage already being done by established exotic species, including the nutria and giant apple snail.
But something could be done to lessen the likelihood of future harmful invasions in Louisiana’s marshes and wetlands, as well as other waterways nationwide. Congress needs to strengthen the Lacey Act, which prohibits the import and trade of harmful species.
Here is how bad the problem is: Since the act’s implementation more than a century ago, only about 40 animal groups have been prohibited, and that usually occurred long after they were imported, escaped into the wild, and started doing damage.
By modernizing the Lacey Act, Congress could empower the U.S. Fish and Wildlife Service to first assess the potential risks associated with a species proposed for import before deciding whether to allow or prohibit its trade in the United States. The ineffectiveness of the current law is easily evidenced by Burmese pythons in the Everglades, Asian carp threatening the Great Lakes, and giant apple snails joining nutria in gobbling up Louisiana’s wetlands.