The United Nations Environment Programme (UNEP) and others have  declared the ocean’s “dead zones” one of the world’s top emerging environmental challenges.

Spreading dead zones have more than doubled over the last decade and are becoming the leading threat to commercial fisheries. The most well-known dead zone is in the Gulf of Mexico. Its occurrence has been directly linked to nutrients or fertilizers brought to the gulf by the Mississippi River.

Each summer, following spring flows from the Mississippi, the Gulf of Mexico experiences a massive die off of bottom-dwelling creatures like crabs and oysters, and sees an exodus of shrimp and fish from traditional fishing grounds along the coast. Scientists say the source of the Gulf’s massive dead zone (8,776-square-miles in 2017) is a condition of low oxygen levels, called “hypoxia,” largely caused by an influx of excess nitrogen from farm fertilizers, sewage and industrial pollutants.

Restoring Nature’s Water Filter

Trout Headwaters continues to promote effective environmental policies and we continue to our energies to restoring and protecting nature’s own, perfect water filters.

Trout Headwaters has worked with the U.S. Army Corps of Engineers Engineer Research & Development Center (ERDC) and many others to demonstrate and deploy improved, vegetative approaches to stabilizing and restoring streams and rivers across the U.S., including in the Mississippi Delta.

THI is dedicated to the development and application of state-of-the art technologies and treatments for restoring critical streamside or “riparian” vegetation. Healthy riparian vegetation acts to filter harmful pollutants, sediments and excess nutrients that wash into waterways from agricultural fields and urban areas.

In an NPR interview, Louisiana State University geologist Paul Kemp commented that excess fertilizer wouldn’t be a problem if the Mississippi, and many of its tributaries, were still connected to their natural floodplains. The genesis of the Gulf’s dead zone was trying to control Mississippi flood waters, said Kemp, pointing out that, “Levees were built from almost the first day the Europeans set foot in Louisiana, so that means the modern river is well-separated from its delta.”

After THI’s years of study alongside technical partners at ERDC in Vicksburg, Mississippi on streams and rivers throughout the Delta, it is clear that the severe historic alteration of these stream channels is a serious, regional problem, and has been exacerbated by the overuse of hard armor “riprap” lining many of those channels, which doesn’t offer the same benefits as trees and shrubs.

Stream channelization (straightening) and levee building has been rampant in the Lower Mississippi Alluvial Valley, While this was done in an attempt to decrease flooding, the side effects have been more significant than we could have imagined.

Healthy Riparian Vegetation Slows and Filters Runoff

Streams and rivers are meant to slowly meander and periodically overflow their banks in a complex hydrologic cycle of erosion and deposition. The problem is that the filter nature designed – diverse, streamside, woody vegetation that slows and purifies water before it enters streams and rivers – has been stripped from thousands of miles of Delta streams and streams throughout the world, to make way for agriculture and development.

“When you combine channelization and levee building with the removal of riparian vegetation and bottomland forests, then throw in hard armor riprap lining stream banks, intensive agricultural practices that farm right up to the edge of streams, and ill-planned urban development, you get an ecological disaster like we’re seeing now through the Mississippi Delta and in the Gulf,” says Trout Headwaters President Mike Sprague. “This scenario has been repeated all over the world, and I applaud the UNEP for recognizing that unless we restore the health of our streams and rivers, not only will we see the collapse of freshwater and marine fisheries, like in the Gulf Dead Zone, we’ll begin to regret having squandered this country’s abundant supply of clean drinking water.”