Ask Lark Weller, a community planner with the National Park Service’s Mississippi National River and Recreation area, the most common question she gets about the Mississippi River and her answer is quick. “Is it safe to swim in the river?” Trevor Russell, watershed program director with Friends of the Mississippi River chimes in with another one, “Is it safe to eat fish from the river?” After struggling for years with how to answer these and other questions posed by the public, the National Park Service and Friends of the Mississippi finally decided to collaborate on a recently released report titled State of the River: Water Quality and River Health in the Metro Mississippi River.
The report examines the health of the Mississippi River in a 72-mile stretch between the Crow River confluence near Dayton and Ramsey to just past the St. Croix River confluence near Prescott and Hastings. The findings, which are broken into five major categories – river flow, swimming and recreation, fish and fishing, ecological health, and other contaminants of concern, paint a picture of a river that is full of life in some locations, alarmingly polluted in others, and always beset by complications.
On the upside, fish in the river have made a remarkable comeback since 1926 when a survey found only two living fish in the 25 miles of the Mississippi south of St. Anthony Falls. (To be clear, the survey did not find two species of fish. It found two fish total.) Today, due to cleaner water and catch-and-release rules, populations of smallmouth bass, catfish, walleye and several other species of trophy fish are flourishing. On the downside, the portion of the Mississippi south of its confluence with the Minnesota River at Fort Snelling is choked with sediment, which smothers aquatic plants and habitat for fish and other aquatic animals and is causing Lake Pepin downstream to fill in at ten times its natural rate.
So, is it safe to swim in the river? The answer is it depends. With the exception of a short stretch of river between the Ford Dam and the Minnesota River, the entire reach of the Mississippi between Coon Rapids Dam and Pig’s Eye Lake has bacterial levels high enough to make swimming unsafe. South of Pig’s Eye Lake, where the river divides Dakota and Washington Counties, the water is usually clean enough for swimming, except for the days following a rainstorm, when stormwater pipes from roads in local communities empty into the river and bacterial levels tend to spike. For this same reason, the report warns against swimming in the river near storm drain outlets at any time of year. Incidentally, these guidelines apply to dogs as well as humans. In places where it is unsafe for humans to swim in the river, it is also unsafe for dogs to swim in or drink from the river.
The question of whether or not it is safe to eat fish from the river is trickier to answer. The Minnesota Department of Health has established site specific safe eating guidelines for fish commonly caught in the Mississippi River. For fish caught between the Ford Dam and Hastings Dam, for example, they recommend eating no more than one meal per week of panfish like sunfish and crappies and no more than one meal per month of larger fish like flathead catfish and white bass. A complete list of guidelines for different types of fish and different stretches of the river can be found at http://www.health.state.mn.us/divs/eh/fish/eating/sitespecific.html. The levels of PCBs (polychlorinated biphenyls) in fish caught from all locations in the Mississippi River have declined dramatically since the chemical was outlawed in the late 1970s, but mercury levels, on the other hand, have increased substantially in fish caught between the Ford and Hastings Dams. A chemical called PFOS (perfluorooctane sulfonate) is also found in fish caught between the Ford and Hastings Dams, especially in the stretch of the river between Cottage Grove and Hastings. Monitoring of bald eagles that nest on the river and feed primarily on fish from the river has also found high levels of contaminants at three specific points: 1) High DDT levels in an eaglet on Durham Island in Brooklyn Center (DDT has been banned in the U.S. since 1972); 2) High lead exposure in eagles near Pigs Eye Lake; and 3) High PFOS levels in eagles near Hastings and Cottage Grove.
In upcoming articles, I will explore specific findings from the Mississippi State of the River report in more detail, as well as highlighting key actions that we all can take to help protect the health of the river and ourselves. Find the report and companion stewardship and policy guides online at www.stateoftheriver.com.