Yes, there are salmon in Lake Superior, though they are not native. These fish were intentionally introduced to the Great Lakes system starting in the mid-20th century as part of a large-scale fisheries management effort. Today, these non-native species have established populations and form the basis of a significant recreational fishery.
The Species Present
Lake Superior is home to four main species of salmon, all originating from Pacific or Atlantic waters. The largest and most sought-after is the Chinook Salmon (Oncorhynchus tshawytscha), often referred to as King Salmon. While Chinook are generally smaller than their ocean counterparts, they can still reach weights of over ten pounds in Lake Superior, though the average catch is typically between three and five pounds.
Coho Salmon (Oncorhynchus kisutch), known as Silver Salmon, are also present and are typically smaller than Chinook, usually averaging between one and a half to three pounds. Pink Salmon (Oncorhynchus gorbuscha), a unique, small Pacific species, are readily identifiable by the large hump males develop during their spawning run, earning them the nickname “Humpy.”
Finally, Atlantic Salmon (Salmo salar) are found in Lake Superior primarily due to targeted stocking efforts near the St. Marys River. This species was native to Lake Ontario before its local extinction in the 1800s.
Why Salmon Are in Superior
The introduction of Pacific salmon into Lake Superior was a strategic response to an ecological crisis. By the mid-20th century, the native Lake Trout (Salvelinus namaycush), the lake’s top predator, had suffered a collapse due to overfishing and the invasion of the parasitic Sea Lamprey (Petromyzon marinus). This created a severe imbalance in the food web.
With the native predator population reduced, non-indigenous forage fish, particularly the Alewife (Alosa pseudoharengus) and Rainbow Smelt (Osmerus mordax), experienced massive population increases. Agencies saw an opportunity to control these exploding forage bases and establish a new sport fishery. The first major Pacific salmon introductions began in the mid-1960s, using Coho and Chinook salmon, which were already successful in Lake Michigan.
Current Status of Populations
Salmon populations in Lake Superior are maintained through a mix of human intervention and natural processes. Chinook and Coho salmon were initially supported almost entirely by ongoing stocking programs, where millions of smolts were released into tributaries. Natural reproduction now contributes substantially to the overall population, particularly for Chinook, with a majority of the fish harvested originating from these naturalized populations.
Pink Salmon established a self-sustaining population in Lake Superior largely by accident after a small number of fingerlings were unintentionally released in 1956. This species is now fully naturalized and reproduces without any stocking support. Atlantic Salmon are still heavily supported by stocking in specific areas like the St. Mary’s River. However, they have recently shown evidence of limited natural reproduction, indicating a slow establishment of wild populations.
Fishing and Consumption Considerations
Lake Superior’s salmon fishery is highly valued, with specific seasons drawing anglers to target the fish both in the open lake and during fall spawning runs in tributaries. Anglers frequently use methods like trolling in the spring and summer to locate salmon feeding on smelt and herring. Catching these large, hard-fighting fish supports a robust recreational industry along the lake’s shores.
Before consuming sport-caught fish from Lake Superior, anglers should consult the most recent consumption advisories issued by health departments. The cold waters contain bioaccumulated contaminants such as mercury and polychlorinated biphenyls (PCBs) that accumulate in fish tissue. These advisories provide guidelines, often species and size-specific, to ensure safe consumption, especially for sensitive groups like children and pregnant women.