Fort Wayne berm built to keep Asian carp out of Great Lakes
FORT WAYNE, Ind. — In the soggy Eagle Marsh, the continental divide rises to a high point along a berm, stretching for 9,000 feet. It slopes so gently that you could call it David.
This man-made berm is up against the Great Lakes’ meanest Goliath: the Asian carp, that can grow from 30 to 100 pounds and fly out of the water. Dangerous if it smacks you in the head. Lethal to native fish and mussels, whose plankton it would devour if it reaches the big lakes.
In 2010, scientists found that, after Chicago’s waterways, this marsh in Fort Wayne was the second most likely place where the carp could invade the Great Lakes. The nonprofit Little River Wetlands Project and government agencies responded that year with a 1,250-foot chain-link fence to serve as a net-like barrier. That would be replaced five years later by a more permanent solution: the massive berm.
Betsy Yankowiak, Little River’s director of preserves and programs, and two researchers lead the way to the front line, hiking a grassy trail that follows the top of the berm. A selfie sign points out the continental divide, where the waters either drain west toward the Mississippi River or east to the Great Lakes.
The group quickly spies a northern leopard frog, which Yankowiak says is prolific here even though it’s on the state’s special concern list, not yet threatened or endangered. She credits the marsh restoration project that began here in 2005. Said to be the largest such restoration in the country, now at 756 acres, it began with a collection of wet farmland. More than 500 acres were seeded with native grasses, wildflowers and other plants, plus the planting of some 45,000 trees and shrubs.
Aside from carp, Yankowiak says Little River has been on the offensive against invasive plants, like the black swallow-wort that was just identified – closely related to milkweed, except that, when monarch butterflies lay eggs on its leaves, the eggs perish.
Behind lies the busy, four-lane Engle Road, with a subdivision on the other side. Across a pond, to the west, sits an office park and a private water treatment plant. Straight ahead are meadows, ponds, prairies and a forest on the horizon where the trees adapt to being flooded. Nine trails, each from 1 to 2 miles, explore all of it.
In the late 1800s, ditches were built in Fort Wayne so that water could drain into the marsh, which floods every year. Or in really high water, it could backflow into the Maumee River, then drain into Lake Erie.
The berm was built to halt carp if flooding ever reached historic, 100-year levels, plus 2 extra feet. Since it was finished in 2015, Yankowiak says, there have been three times that floodwaters rose high enough so that carp could have crossed if no barrier existed. In February, the area escaped the historic floods we saw in Michiana.
The builders left a 350-foot gap in the berm, with fencing, to avoid a backup that could cause flooding in downtown Fort Wayne.
By contrast, in Illinois rivers, where electric shock is used as a barrier, federal officials say that about $40 million per year is spent to control Asian carp. Contractors there remove hundreds of thousands of pounds of the boney fish, used for fertilizer.
The group walks down from the berm, rounding a pond and come by a ditch, gushing over stones, where the habitat has become more like a stream.
Yankowiak points out an “overachiever,” the native compass plant that will grow taller than an adult human, with flowers and broad, flat leaves that orient themselves from north to south.
Little Rivers started in June to count turtle roadkill on Engle Road. Researchers are studying ways to keep turtles from crossing the road – perhaps by using a fence to suggest other routes. They are also building habitat so the turtles won’t need to cross the road, says Bruce Kingsbury, a professor at Purdue University Fort Wayne.
In his studies here, he says helpers used cans of sardines to lure turtles into nets, and in two weeks this spring counted 100 painted turtles and almost 50 snapping turtles. A Bioblitz event in 2014 had found two of the endangered Blanding’s turtles.
Great egrets, blue-spotted salamanders, crawfish and minks live in the marsh, where at least 234 bird species have been counted. But still no sign of Asian carp.