Wisconsin's Public Liberal Arts College

Aquatic Habitat Structures


Lake Superior Research Institute

Aquatic Habitat Structures

RECYCLING EARLY SUPERIOR LOGS FOR FISH CRIBS

Coarse woody debris is almost absent in the Hog Island inlet as contaminated soil and sediments were removed in 2005. Early accounts of the area discuss the expansive collection of woody debris in the St. Louis River and Allouez Bay area, including the Hog Inlet area. It was told that a person could walk across from the mainland to Wisconsin Point without ever getting their feet wet. Today, much of the debris has been removed for logging, salvage or to protect navigational routes.

The Hog Island Inlet provides an opportunity for habitat enhancement through the introduction of coarse woody debris, including floating logs anchored on one end, anchored structures placed in the remediated areas of the inlet and logs washed up along the shore.

Pier pieces from Connors Point were removed and utilized in the construction of 20 fish cribs. At the time they were cut (1880's), the red pine lumber was 200 years old. These pier pieces supported a sawmill, then later a floating power plant over the water. They remained in the water until 2008 and are now being recycled as fish habitat in the Hog Island inlet.

These areas of woody debris form critical habitat for the inlet ecosystem. The underside of near shore logs provides abundant habitat niches for aquatic macro invertebrates that feed minnows which in turn feed larger fish species. Water insects such as mayflies graze on the algae that grows on the slowly decomposing wood. Fish from walleye to muskellunge to whitefish use these logs as nursery logs. Above water, a log becomes a resting spot for waterfowl, shorebirds and turtles. Muskrats use these logs for feeding platforms. Predators such as mink and otter hunt near these logs for the prey they consume.


Back to Top