In 2016, Wisconsin used 385,000 cubic yards of harbor mud to rebuild vanished Cat Island; more than 30 bird species returned, and 3 piping plover chicks fledged

Somewhere along the marshy edge of Lake Michigan, in a stretch of water few Americans have ever heard about, a bird nearly lost to history is raising chicks again in the mud, specifically, land built up from sediment dredged out of a shipping channel. It's one of the few quietly triumphant conservation success stories the US has gotten in the last decade, and it starts, unassumingly, with muck. According to a 2016 report from the U.S. Army Corps of Engineers' newsletter, “The Corps Environment,” engineers had by 2015, one year into the sediment-placement phase that began in 2014, already deposited over 385,000 cubic yards of clean dredged material from the Green Bay Harbor channel onto the landmass known as Cat Island. The reward was swift: more than 30 species of Great Lakes shorebirds showed up and, that same summer, an endangered pair of piping plovers fledged three chicks: the first plover nesting in that bay in 75 years.

A landmass lost to erosion, then deliberately rebuilt

Cat Island was never an accident, either in its loss or its return. It was, formerly, a storm-buffering barrier chain known as the Cat, Willow and Bass Islands that used to help protect Green Bay's shoreline for centuries before it was washed away in the 1960s and '70s. Losing the island did not just mean losing a scenic view; it also meant losing nesting ground for shorebirds and left the bay more vulnerable to wave damage at a point when the area was considered a Great Lakes "Area of Concern" for issues like pollution and habitat loss.

The engineering plan was straightforward in concept, if not in execution: since the Army Corps of Engineers had to dredge Green Bay's shipping channel to keep cargo traffic flowing, and the material had to go somewhere, engineers reasoned that it could be used to rebuild the island instead. Construction of the stone wave barrier began in 2012, with dredged material placement following in 2013–2014. It was a slow process; the Corps expected to keep adding sediment for another two decades or so before a total of roughly 274 acres of land and 1,400 acres of wetland would be restored.

The plover problem, and why three chicks matter so much

To understand why three fledged chicks matter so much, one needs to understand just how close the piping plovers were to vanishing from the Great Lakes. Listed as an endangered species in 1986, a nesting pair of plovers hadn't been seen anywhere near Green Bay in decades. So when a nest appeared and fledged three young, biologists took it as a strong scientific signal that engineered habitat could work, one reinforced by the attention the milestone drew nationally.

It wasn't a one-time thing, either. According to this 2025 update from the U.S. Fish & Wildlife Service, plovers have nested at Cat Island every year since 2016, fledging a combined total of 68 wild-hatched chicks over that stretch, and as of 2023, a pair was even found nesting two miles away at Longtail Point.

Worth the effort, but not a miracle cure

A healthy amount of skepticism is due here. After all, rebuilding an island out of dredged sediment sounds efficient, but it's taken over a decade to get to this point, and the Corps has plenty of material to dump in the next two decades or so before the project is complete. What looked like a simple engineering fix on paper was, in practice, anything but quick. According to this University of Wisconsin Sea Grant overview of the Cat Island Chain restoration, the idea dates back to conversations in the late 1970s, meaning it was a decade-long planning, funding, and interagency cooperation process before a single shovel of land was protected with mud.

This may seem like the less inspirational part of this story: rebuilding waste turned out to be a neat piece of engineering, but it's also a reminder of the time, money, and bureaucracy that goes into American conservation projects, even the ones that work. A win for plovers, but a win that still took 40 years and a small army of federal, state, and university partners to happen.