Habitat Disappearing

A more visible result of sediment loss has occurred in the Mississippi River Delta at the Gulf of Mexico.

“That’s the final resting place,” Jacobson said. “It’s just like any kind of accounting system. If you decrease how much goes in, you decrease how much comes out.”

And less output means less material to create wetlands along the Gulf.

“It’s well documented that wetlands (around the Delta) have been disappearing,” Jacobson said.
Wetlands are important habitats for animals but also provide a buffer between land and sea. In events such as hurricanes, surges of water can be partially absorbed by healthy wetlands. Some scientists link the disappearance of Gulf wetlands to the severity of damage caused by Hurricane Katrina.

Regaining healthy wetlands is not just an issue of quantity but also of speed. The water pouring out of the mouth of the Mississippi is moving much faster than it has in the past because of 20th century river-straightening efforts. Jacobson noted that much of the remaining sediment gets propelled through the Delta, with little chance to settle out into the wetlands, and dumped into the Gulf of Mexico.

Although scientists are calling for more sediment to restore the Delta, they are also cautioning about the effects of runoff on the Gulf.

Excesses of nitrogen and phosphorous are being blamed for the oxygen-starved dead zone that covers between 5,000 and 12,500 square miles in the Gulf of Mexico, said Michael Gossenauer, a hydrologic engineer for the water quality division of the corps’ Kansas City District.

Although nitrogen and phosphorous occur naturally in soil, high amounts of these water-soluble nutrients in fertilizer can end up in streams, rivers and eventually oceans. Other sources of detrimental nutrients include wastewater treatment plants and urban runoff.
When nutrient levels get high enough, aquatic plants, such as algae, thrive. But as these plants die, bacteria flock to feast on the decomposing jungle and comsume so much of the dissolved oxygen that little else can survive. A dead, or hypoxic, zone is born.

The Environmental Protection Agency created a Hypoxia Task Force to research ways to combat excessive nutrients in the nation’s rivers.

“Hypoxia is a national issue,” said Ed Galbraith, the director of staff for the state Clean Water Commission, which is run through the Missouri Department of Natural Resources. “These issues have to be coordinated on that level.”

Aside from the red flags raised by hypoxia, introducing any kind of extra sediment to the river goes against decades of engineering practices, and agricultural and environmental policy. Yet that is precisely where scientists are trying to direct political policy.

“The general trend is that we’re trying to get more sediment into the river,” Gossenauer said. But they have a substantial precedent to swim against.
In 1933, President Franklin Roosevelt authorized the first major dam along the Missouri River, recasting the river for navigation, flood control and irrigation.

Aimed at conserving productive soil for farming, the 1935 Soil Conservation Act was the first federal law to take on erosion. Almost four decades later, the Clean Water Act went so far as to list sediment as a pollutant.

Missouri has been a front-runner in reducing soil erosion since voters approved the parks and soils tax in 1984 and renewed it in 2006. Some of the one-tenth-cent sales tax goes to help landowners with conservation projects designed to keep the soil out of waterways.

In coming years, the National Academy of Sciences will be taking a long look at sediment in the Missouri River. The academy’s two-year study is slated to begin in February.

“We’ve managed the landscape for social and economic benefits,” Jacobson said. “Along the way, we’ve realized that some of those (decisions) have had detrimental effects. Now we’re trying to work with these budgets of sediments and nutrients to improve on their distribution and prevent imbalance.”

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channel of time

1912
U.S. Army Corps of
Engineers begins
federally authorized changes to the Missouri River channel.

1933
President Franklin
Roosevelt authorizes the construction of Fort Peck Dam in Montana, the first major dam along the
Missouri River.

1935
U.S. Soil
Conservation Act passed.

1944
Flood Control Act passed.

1972
Federal Clean Water Act passed.

1973
Endangered Species Act passed.

1984
Missouri voters approve sales tax for parks and soil
conservation.

1993
Major flood along Missouri and Mississippi rivers.

1994
Creation of the Big Muddy National Fish and Wildlife Refuge.

1995
Second major flood in two years on
Missouri River.

1999
Water Resources Development Act directs corps to improve aquatic habitats along the Missouri River.

2000
U.S. Fish and Wildlife Service issues a formal opinion to the corps, asserting that the corps’ actions are jeopardizing the survival of species, including the pallid sturgeon.

2006
Sept. 25 — Corps awards Jameson Island construction contract to Big Rivers.

Oct. 18 — Corps gives approval to construction company to begin work.

2007
March — Howard County farmers report corps dumping dirt at Jameson Island.

April 23 — Missouri Clean Water Commission makes first request to corps to cease dirt disposal in the river.

April. 25 — Corps suspends construction contract to halt work.

July 6— Corps restarts construction at Jameson Island and sidecasts dirt, meaning it is put alongside the chute rather than in the river.

Sept. 12 — Clean Water
Commission issues formal order to corps to stop construction on all Missouri River habitat sites.

Sept. 20 — Corps acknowledges commission order, but makes no promise to comply.

Oct. 5— Corps again suspends construction contract.

Oct. 25— First meeting among corps, the Missouri Attorney General’s Office and the Department of Justice.