Ecologists lead program on aquatic life in rivers

BONAPARTE – Curious onlookers got to feast their eyes on all manner of marine animals Saturday morning, Aug. 17, during a program called 'Aquatic Life of the River” in Bonaparte, Van Buren County.

A team from the State Hygienic Laboratory of the University of Iowa demonstrated how the team assesses the health of a river, in this case the Des Moines River. The team catches fish and records facts about them such as their species, length, and any lesions, which could be caused by poor water quality. Team members don't rely on their casting skills to catch the fish. Rather, they use a device consisting of electrified poles that hang in the water at the front of their boat, creating an electric field that attracts fish. Not only that, when the fish get really close they receive an electric shock that temporarily stuns them (without harming them), allowing a member of the team to scoop the fish into a net.

The boat returned to shore after collecting more than a dozen species of fish in the river. A crowd gathered at the dock to see what the team had found: an Asian carp, catfish, blue sucker, river carpsucker, shortnose gar, blue gill, sturgeon, and an enormous buffalo sucker, just to name a few. Children petted the fish before a member of the team threw them back in the river. By then, the electric shock had worn off and the fish were anxious to return to the water.

Assessing river health

Mike Birmingham of the University of Iowa's State Hygienic Lab was one of the aquatic ecologists on hand for Saturday's event. He said the state has come a long way in the details it gathers about its river quality. He said that, in the 'old days,” ecologists just checked the ammonia and oxygen levels of the water. But beginning about 20 years ago, they started gathering insects and fish to assess their health, too.

Some insects are hardy and can live even in the most polluted of streams. Others are more sensitive to contamination, and these are the insects Birmingham and the other ecologists are most interested in. The presence of sensitive insects like stoneflies, mayflies and caddisflies, is a sign the river is healthy. If they're absent, it could mean the water is polluted.

Iowa's water quality today

Birmingham said he regards most of Iowa's rivers to be of 'fair to OK” quality. He acknowledged that the advent of farming changed rivers substantially, especially in Iowa where so much of the land – 85 percent according to Living History Farms – is dedicated to row crops.

'Southeast Iowa has more forest and grazing, so the streams here have been less affected than other parts of the state where the rivers have been straightened,” Birmingham said.

Iowa's water quality is notably better than it was a few decades ago in the era before the Clean Water Act of 1972 and other environmental regulations. Birmingham noted that in the 1960s and 1970s, rivers near meat-packing plants or factories would be bereft of life for miles on end because of the pollution and resulting lack of oxygen.

'Before the early 1970s, there was almost no treatment of sewage,” Birmingham said. 'Downstream of meat-packing plants, the water would be red from blood. In Omaha back in the 1960s, there were guts for miles downstream of its packing plant. It was really bad, and those issues have been addressed pretty well.”

Birmingham was asked about the trends he saw in Iowa's rivers. He mentioned that flooding in recent years has made streams wider, especially in northeast Iowa.

'Streams that used to be 15 feet wide are now 40 feet wide from the massive floods,” he said.

Birmingham said the floods have brought silt and sand, which covers the rocks that once lined the riverbed. He said this affects fish that need to lay their eggs on rocks.

Insects

How does the team from the state hygienic lab assess the health of river insects? They look for areas where water is moving fast over clean rocks. Insects will try to cling to the rocks so they're not swept away. The team nudges the insect into a net just below the surface of the water.

The insects are preserved in an alcohol-based solution. At Saturday's event, the ecologists had a table full of insects in bottles, ranging from tiny flies to huge crawfish and parasitic lamprey that survive by latching onto fish.

Partnership

Saturday's program was made possible by a partnership between Jefferson County Conservation and the Department of Natural Resources Water Trails. Since Van Buren County does not have its own naturalist, it pays Jefferson County Conservation to cover the cost of events such as the one on aquatic life. Jefferson County Naturalist Brittney Tiller said this is the third year of the partnership between the two counties.

Tiller said that the program on aquatic life was timed to occur during Bike Van Buren, an event in which cyclists visit all the Villages of Van Buren County. Several cyclists who rode into Bonaparte Saturday morning came to the boat ramp to take in a portion of the program.