Data show positive trends in Mississippi River
by T.W. Budig
ECM Capitol Reporter
Bald eagles pluck fish from lengths of the Mississippi River, once so polluted as to be nearly without fish. And other signs show a resiliency in the big river, a capacity to heal, suggesting environmental transgressions, properly atoned, may be forgiven.
But former Department of Natural Resources Commissioner Gene Merriam, of the Freshwater Society, looks to the future of the Mississippi River and other waters with mixed emotions.
“It can vary day to day,” Merriam, a member of the ECM Publishers board of directors, said of his belief in humanity’s ability to live sustainably.
Still, history shows that commitment, good law and adequate resources can bring positive change.
“And the Mississippi is a good example,” Merriam said.
More data for judging is coming in.
The Minnesota Pollution Control Agency is assessing the state’s largest rivers. During the next five years, MPCA crews will be checking fish, aquatic invertebrates, water chemistry and other indicators of health in the Mississippi, Rainy, Minnesota, Red and St. Croix rivers.
First is the Mississippi, with MPCA crews testing and sampling from Itasca State Park at its headwaters to St. Anthony Falls in Minneapolis.
On a recent sunny morning, a MPCA boat slipped off the Mississippi shoreline downstream from Columbia Heights, electroshock cables dangling in the water like feelers.
The crew, with nets in hand, stood on the bow, ready to scoop-up what the river offered.
At the helm was MPCA research scientist Michael Feist, who attended Coon Rapids High School and who is no stranger to the Mississippi.
“I swam in the river all the time,” Feist said. “I probably still would today. And up by Anoka, there’s no problem. I wouldn’t hesitate.”
Feist and his crew were finishing one phase of the river assessment. Aquatic invertebrate sampling and water chemistry testing continues.
The amassed data is scheduled to be analyzed by the MPCA over 2015-16, Feist said. At that time, a more precise picture of the Mississippi’s health will emerge.
So far, Feist hasn’t been alarmed.
“The Mississippi River, from what I’ve seen, generally looks pretty good,” he said.
Earlier surveys show trends
Others have been studying the river, as well. Friends of the Mississippi River and the National Park Service’s Mississippi National River and Recreation Area recently jointly published a state of the river report.
In it, the groups, tapping into pools of scientific data, tried to measure the status of the river through a variety of indicators.
“The river is healthier; the fish are back,” said Whitney Clark, executive director of the Friends of the Mississippi River.
A 1926 fish survey lends credence to the portrayal of the Mississippi of decades ago as an open sewer. The survey found only two living fish within the 25 miles downstream of St. Anthony Falls, the report notes.
In addition to more plentiful fish, bald eagles, once on the brink of extinction in the lower 48 states, soar over the river. Indeed, the numbers rival the eagle populations to the north, Clark said.
Some contaminants bedeviling the river are abating.
Levels of PCBs, an industrial by-product appearing in the 1930s and a topic of fish consumption advisories, have decreased. Although mercury pollution peaked 50 years ago, and accumulation rates in Lake Pepin sediments have decreased by 70 percent, recent studies suggest the need for ongoing vigilance, the report notes.
The Mississippi meets drinking water standards for nitrates. But nitrate levels increased by 47 percent from 1976 to 2005, the report notes, with factors such as increased agricultural production and use of fertilizes contributing to the rise.
Looking elsewhere, the report notes the flow rate on the Mississippi has increased by 25 percent since 1976, as measured at Hastings Dam. The flow rate on the Minnesota River, which joins the Mississippi at Fort Snelling, has doubled during the past 70 years, the report notes.
It’s theorized the increase agricultural drainage, urban runoff and changing weather patterns have contributed to the bank-eroding increase in water flow.
While Feist has no hesitation swimming in the river near Anoka, bacteria levels downstream in the Mississippi are concerning, the report notes. From Coon Rapids Dam to the Ford Dam in St. Paul, levels are high enough to recommend contact with river water be limited.
Urbanites can help reduce bacteria levels by cleaning up pet wastes, checking septic systems and taking steps to limit storm water runoff, the report suggests.
Phosphorus — a chemical needed for plant growth but, in excess, can cause oxygen-depleting algae blooms — has decreased in the river over recent decades. Yet Lake Pepin is impaired by excess phosphorus and threatened by the fish-killing algae bloom during low water, the report notes.
Phosphorus is not entering Lake Pepin – a widening in the Mississippi River below Hastings – in an even manner. Only about a quarter of the load is coming from the Upper Mississippi, according to the report. More than half, 52 percent, comes from the Minnesota River.
The Minnesota River is a heavy actor in terms of sediment pollution, too. Sediment, tiny bits of dirt or plant material, darkens the water and fills in river beds. About 75 percent of the sediment in the Mississippi comes from the Minnesota River basin, according to the report.
It’s estimated the sediment load on Lake Pepin is about 10 times the pre-European settlement rate. Starting in the 1930s and over the ensuing three decades, the sediment load to Lake Pepin more than doubled from 300,000 to 700,000 metric tons a year, the report notes. The 30-year period coincides wetland drainage, the intensification of agriculture, ditching to farmland and increased urban development.
Responding to pollution
In citing environmental advances, Merriam and Clark point to the Clean Water Act of 1972 as a major milestone.
However, the landmark legislation is defective in one way, Clark argued: It failed to adequately address agricultural pollution.
“So it’s legal to massively pollute public surface water,” he said.
Merriam portrays the agricultural industry as in denial in terms of acknowledging the threat current agricultural practices present to water.
Minnesota Farmers Union official Thom Petersen, in an email, disagreed.
“I don’t feel we are in denial at all,” he said.
“Farming practices are changing rapidly that will have a positive impact on the river and its estuaries. More and more no-till, reduced tillage, precision agriculture, variable rate applications of fertilizers and pesticides are changing rapidly,” Petersen said in part.
Diagnosing pollution is complex, Feist said. Things are rarely black and white.
“We all need to do our part,” he said of protecting the river.
The MPCA is about half-way through a 10-year project to assess the condition of smaller rivers, streams and lakes in Minnesota’s 81 watersheds, according to the MPCA.
Tim Budig can be reached at [email protected].