North Shore trout streams
North Shore creeks are great scenery but are only fair trout streams. They depend on runoff, so their flows are unstable, surging after a rain, dwindling to a trickle during drought and the winter season. In the summer some stretches get warmer than is best for trout. In their lower reaches, these streams cascade over falls and steep rapids. As pretty as these features may be, they are not conducive to growing trout, which must find niches of quiet water amid the turbulence.
A trout stream on the North Shore.
The volcanic bedrock over which they flow has few of the water-soluble minerals that help keep the water alkaline. Consequently, these streams tend to be soft, slightly acidic to neutral, and not very productive. Because they lack spring water, the streams get very cold in winter. In fact, "anchor ice" sometimes forms on the bedrock of the streambed, destroying aquatic life and habitat.
Despite their shortcomings, North Shore streams have two things in their favor. First is their cool, northern, lake-moderated climate. Second is the deep-forest bank cover, which shades the streams and keeps them cool. These influences keep these streams just cool enough to support trout.
Interestingly, trout are not native to the upper reaches of the North Shore streams. Brook trout occupied Lake Superior and ascended the rivers as far as the first barrier falls-usually less than a mile from the lake. Only during the last century have brookies been stocked above the barrier falls. The DNR stocks brook trout in heavily fished creeks in and near Duluth, though brookies are self-sustaining in many North Shore streams. The smallness of the streams and their low productivity prevent many trout from exceeding a foot length. As one North Shore fisheries manager noted: "We can raise a lot of small fish." In the deeper water of seclude beaver ponds brookies may reach two pounds. But in the long run, beaver dams do more harm than good, warming the water and contributing to siltation. North Shore trout management includes breaching beaver dams.
In North Shore streams that provide marginal trout habitat, the DNR stocks brown trout, which tolerate warmer water than brookies do. Some large streams are stocked with small steelhead and chinook salmon, which migrate to the lake-the steelhead fry in two to three years, the salmon smolts within days.
Northeastern Minnesota maps (updated Spring 2007)