DULUTH -- From the water, the old wood pilings sticking out of the St. Louis River Estuary appear as ghostlike arms of long-gone industry.
More than 100 years ago, the pilings held buzzing sawmills that helped build this inland sea city. But the byproducts, slipped into the water and out of sight, still haunt: thousands of tons of wood waste covering 75 acres of river bottom, piled 20 feet thick in some spots and inhibiting the natural ecosystem.
This summer, officials with the Minnesota Department of Natural Resources are embarking on a $16 million initiative to restore habitat here. That's just a fraction of an estimated $300 million to $400 million in projects now underway to restore the 12,000-acre estuary, put onto a list of Great Lakes Areas of Concern three decades ago by an international commission.
The estuary is the primary nursery for more than 40 species of fish in western Lake Superior, including walleye, lake sturgeon, northern pike and smallmouth bass, according to the DNR. It provides habitat for more than 230 species of migrating and resident birds. And increasingly, it's being viewed by the city of Duluth as an underrecognized natural amenity for locals and tourists.
"This waterway is of statewide and nationwide importance," said Kris Eilers, executive director of the citizen-based St. Louis River Alliance, which lobbied for cleanup funding. "It's a unique freshwater estuary. There's not very many of this size."
While officials are pleased to see the cleanup accelerating now, decades into the work, it's clear that cleaning and restoring the mouth of river is a long, bureaucratic and even sometimes tedious process.
A floating excavator's long yellow arm dipped into the water one morning last week, its red clamshell claw scooping up sediment that had washed into a portion of the estuary known as Kingsbury Bay.
Though not contaminated, the bay has become shallow after years of runoff from urbanization and extreme storms.