Lake Superior

Why Superior fishes the way it does

Superior is cold, deep, and poor. That is not an insult — it is the whole explanation. The basin is scoured granite and basalt with very little agricultural runoff feeding it, so there is not much dissolved phosphorus, not much plankton, and not much of the biological engine that turns sunlight into fish flesh. Biologists call it oligotrophic. Anglers call it big empty water.

The consequence is that Superior grows fewer fish than the lower lakes, and it grows them slowly. A lake trout that would be four years old in a fertile lake takes eight or ten here. The upside is that those fish live a long time. Superior lake trout past 25 years old are routinely aged out of creel samples. You are not fishing a crop. You are fishing an accumulation.

Cold also organizes everything vertically. Superior stratifies late and weakly compared to the rest of the chain, and the deep water never really warms. Fish that need cold — lakers, whitefish, cisco, burbot — have the run of the lake and can be almost anywhere in the water column depending on the month. Fish that want warmth get squeezed into a narrow band along shore and into the bays. Learn where 50-degree water is on a given week and you have solved most of the puzzle.

The lamprey and what almost happened

The most important thing that ever happened to this fishery arrived through a canal. Sea lamprey reached the upper lakes after the Welland Canal was reconstructed, and by the late 1940s they were established in Superior. A single lamprey kills roughly 40 pounds of fish in its parasitic phase. The lake trout population — the top predator, the native fish, the commercial backbone of every port from Duluth to Whitefish Point — collapsed.

Commercial lake trout landings on Superior fell by better than 90 percent inside of a decade. Ports that had run trout boats for three generations stopped. The United States and Canada stood up the Great Lakes Fishery Commission in 1955 specifically to deal with it, and the answer turned out to be a selective lampricide, TFM, applied in the tributary streams where larval lamprey burrow into the silt for years before migrating out.

It worked, and it has to keep working forever. Lamprey control on Superior’s tributaries is an unglamorous, permanent, annually funded piece of infrastructure, and it is the reason there is a lake trout fishery at all. Superior recovered better than any other lake in the system because enough wild fish survived in deep refuge water to rebuild from. That is why the fish you catch here are wild and the ones in Lake Michigan are mostly stocked. It is also why nobody who works on this lake treats invasive species as an abstraction.

The ports worth launching from

Duluth and Superior sit at the western tip and share the largest harbor on the lake. Protected water, a working freighter port, and access to the shallow warm end where coho show up first in spring.

Bayfield, Wisconsin is the gateway to the Apostle Islands, and the islands are the practical answer to Superior’s biggest problem. Whatever direction the wind comes from, there is a lee somewhere in the archipelago. Lake trout, smallmouth in the warm shallow bays, and the most forgiving big-water fishing on the lake.

Marquette, Michigan is the best all-around base on the south shore: a protected harbor, deep lake trout structure inside a short run, coho along the beach in spring, and enough town that a blown-out day is not a wasted one.

Munising puts you behind Grand Island with the Pictured Rocks cliffs as scenery and a genuinely good splake and lake trout fishery in the bay. It also freezes reliably, which makes it one of the more dependable ice destinations.

Grand Marais, Minnesota and the North Shore ports are small, exposed, and spectacular. Steep basalt shoreline, deep water close in, and steelhead rivers every few miles. Launch capacity is limited and the weather window matters more here than anywhere.

How to approach the lake as a visitor

Plan around weather, not around dates. Book a week, not a day, and accept that two of those days will not be fishable. Everyone who fishes Superior regularly plans this way; it is not pessimism, it is how the lake works.

Check the marine forecast the night before and again at the ramp. If the forecast says four feet and you are in a boat you would take on an inland lake, stay in. The lake is not going anywhere and Superior does not hand out second chances the way a shallow lake does.

Dress for the water temperature, not the air. That is the single piece of advice every guide on this lake gives and the one visitors ignore most. A 75-degree July morning over 42-degree water is still an immersion hazard, and a float coat or an inflatable PFD worn — actually worn, not stowed under the console — is the difference between an embarrassing story and a fatality.

Hire a charter for the first day if you can. Superior rewards local knowledge more than any other lake on the chain because the productive structure is scattered, deep, and invisible from the surface. One day with somebody who knows which reef holds fish in which week will save you a season of guessing.

And carry a chart, a plotter, and a handheld VHF. Cell coverage on this coast is a courtesy, not a service.