Long-term challenge: Restoring tributaries
Nancy Larson & Karen Plass
One reason we restore lake-spawning species like lake trout, lake whitefish and lake herring is that their habitat stayed generally unaltered, said DNR fish biologist Dennis Pratt. It won't be that simple for stream-spawning species such as walleye, northern pike, brook trout and lake sturgeon.
"Restoring the stream fishery is tougher due to tremendous damage that's been done to the watersheds. Compared to the lake, the tributary and river-mouth estuary habitats have been highly degraded," Pratt said.
Stream watersheds were changed by logging, forest fires, and ditches to drain agricultural lands and road construction.
"We had a forest-protected watershed. The problem is that we have changed the land so it sheds water more quickly to the streams, creating erosion and increasing channel size. Stream channels in clay don't snake back and forth. Now they cut down, or incise. As they straighten out, they remove wood and increase their slope, becoming culverts of fast moving water, "Pratt said. "The upper Fish Creek channel has incised nine feet since 1947, and the lower stream channel is three feet higher because of sand deposited there."
Tight clay soils and loss of original ground cover allow rapid runoff into tributary streams. This increased flow carves at streambanks and bluffs, which accelerates erosion. Rapid runoff can damage bridges and culverts, and can seriously degrade instream habitat, including gravel beds where brook trout spawn.
Brook trout, the only native stream trout in the Great Lakes, are a good indicator of coldwater stream health. Years ago, legendary Chequamegon Bay brook trout, large sized and easily caught, were depleted by anglers. At one time, brook trout in Wisconsin's South Shore streams could connect to the lake, but today they thrive mostly in disconnected stream headwaters, Pratt said.
There is much interest in trying to restore "coaster" brook trout, formerly found along some areas of the Lake Superior shore. Recent research suggests that coasters are not a unique variety of brook trout, but are fish that move out of streams and live along the shore, where they grow more quickly. At maturity, they return to their home stream to spawn. "If this is the case, we would need to significantly improve our watersheds that drain to brook trout streams before they could export many 'coasters' to the lakeshore habitat, Pratt said.
He adds that we can improve the watersheds, but there are no quick fixes. "Restoration may be a very long-term goal," Pratt said. "We need to work together, improving watershed conditions, to restore the quality stream habitat that brook trout require. We can identify important spawning areas and work with upstream landowners to avoid harvesting too much timber at once from critical watersheds."
|Reclaiming Orienta Falls|
In 2001, Xcel Energy (formerly Northern States Power) removed an old power dam from the Iron River, about 1.5 miles above where it enters Lake Superior. What had become a warmwater flowage as large as 144 acres became, once again, 1.2 miles of trout stream.
"This was a major victory for the environment," said Duane Lahti, DNR Lake Superior basin water supervisor, who has worked on this project on and off since 1985. "A river system has been reconnected here. An ugly barrier was removed from the sandstone outcrop known as Orienta Falls, which old newspaper articles called the most scenic site in Bayfield County."
At the falls, water drops 15 to 20 feet over a distance of 200 feet.
The original hydropower dam, constructed in 1923, was destroyed by a flood in 1946. A replacement dam 56 feet high operated until 1985, when it was severely damaged by a flood. Before final dam removal, the DNR and Great Lakes Fishery Commission constructed a low-head barrier to keep sea lamprey and migratory fish out of the 56 miles of trout stream in the Iron River watershed.
Many people favor returning the Iron River to a migratory stream, but there are also concerns about potential impacts of migratory fish on resident fish and on the Iron River National Fish Hatchery on Schacte Creek, a headwaters tributary. Until a management plan is developed, fish migration from Lake Superior will remain blocked. In the meantime, the river is returning to a more natural state. Below the old dam site, lake-run salmon and trout are reproducing once again.
|Project reduces mercury|
"We looked at the ways mercury in our community could get into our treatment plant or into the environment, and worked on educating and giving people alternatives," said Diane Thompson, Superior's Pretreatment Coordinator.
With federal and state funding, staff held workshops for health care workers, teachers and building contractors. In 1999, they surveyed municipalities around the basin and sponsored a pollution prevention workshop that spurred basin wide collaboration.
Energy efficiency is an important goal, since burning coal to produce energy is a major source of mercury. Fluorescent tubes are energy efficient, but contain enough mercury to cause environmental problems if they aren't recycled. Superior's wastewater treatment plant and local businesses initiated a fluorescent tube recycling program for county residents.
The Northwest Wisconsin Regional Planning Commission (NWRPC) Northwest Cleansweep Program offers collection opportunities for mercury-containing products and other household hazardous wastes. Residents have given more than 7,000 mercury-containing items such as thermometers and thermostats to Superior and Northwest Cleansweep. Thompson estimates they have removed over 350 pounds of mercury since 1999.
Schools and students have been important allies. Thirty schools participated in the Northwest Wisconsin Mercury Free Schools Project in 2001.
Pledging to get mercury out of buildings, schools conducted audits to locate mercury and other hazardous materials on site. Students developed skits, essays, songs and posters, and organized a thermometer exchange.
A Maple, Wis., high school turned in, from their science labs, almost a dozen Boyle's Law apparatuses. These outdated pressure-measuring devices contained two pounds of mercury each!
"We were happy to remove so much mercury from circulation," said Bill Welter, NWRPC administrator for Northwest Cleansweep.
Nancy Larson is Wisconsin DNR's Lake Superior program coordinator. Karen Plass is a former Lake Superior specialist with the Wisconsin DNR and former executive director of the St. Louis River Citizens Action Committee; she currently works for the University of Minnesota-Duluth.