Salmon species are present in Lake Superior, forming a significant component of the current ecosystem and regional sport fishery. These fish were not originally native but have been successfully introduced and established over the past several decades. The presence of salmon provides diverse recreational opportunities for anglers across the states and province bordering the lake. Their populations are actively managed by various state and provincial agencies to balance the needs of the sport fishery with the overall health of the aquatic environment.
Identification of Salmon Species in Lake Superior
The majority of salmon species found in Lake Superior belong to the Pacific salmon genus, Oncorhynchus, despite the lake’s location in the Atlantic drainage basin. The most common species are the Chinook Salmon, Coho Salmon, and Pink Salmon, all of which are sustained through a combination of stocking and natural reproduction.
Chinook Salmon (Oncorhynchus tshawytscha), also known as King Salmon, are the largest of the introduced species and often reach weights between 7 and 15 pounds in Lake Superior.
Coho Salmon (Oncorhynchus kisutch), often called Silver Salmon, are also widely present, and most of their population is now supported by natural reproduction in the lake’s tributaries. Coho typically spend about a year and a half in the lake before returning to spawn.
Pink Salmon (Oncorhynchus gorbuscha), or Humpback Salmon, are unique because their initial introduction to the lake in 1956 was accidental, but they quickly established a self-sustaining, naturalized population. Pink Salmon are distinctively smaller, generally averaging only about three to four pounds. Atlantic Salmon (Salmo salar) are also occasionally caught, though their presence is much more sporadic and they are not established as a robust, self-sustaining population.
Non-Native Status and Introduction Methods
All current salmon populations in Lake Superior are non-native, having been intentionally or accidentally introduced to the Great Lakes system. The initial widespread introductions of Pacific salmon occurred in the mid-1960s, primarily in an effort to fill a vacant ecological niche. This void was created by the decline of native predator fish, most notably the Lake Trout, which suffered from extensive commercial overfishing and the destructive invasion of the parasitic Sea Lamprey.
State and provincial agencies began stocking Pacific salmon to diversify the sport fishery and utilize the burgeoning population of non-indigenous forage fish like Rainbow Smelt. The stocking programs were intended to create a “put-grow-take” fishery, meaning fish were stocked as fingerlings or smolts for anglers to catch later.
While some jurisdictions have since discontinued Chinook stocking, others continue to stock Chinook Salmon to maintain the population and support angling opportunities. The success of these programs resulted in naturalized populations for Chinook, Coho, and Pink Salmon, with wild-produced fish now accounting for the majority of the catch in many areas.
Impact on the Lake Superior Fishery
The presence of these introduced salmon species has had a transformative impact on the Lake Superior fishery, chiefly by creating a highly valued recreational sport. Anglers actively pursue these fish throughout the year using different seasonal methods. During the warmer months, fishing is centered on open-water trolling, where boats equipped with specialized gear target the cooler, deeper sections of the lake where the salmon feed.
A significant part of the angling season occurs during the fall spawning runs, when salmon migrate into the tributary rivers and streams of Lake Superior. This period offers a popular stream fishery, allowing anglers to target the fish from shore or small craft as they return to their natal or stocking streams.
The economic activity generated by this sport fishery, including charter boat operations, tackle sales, and lodging, is a significant benefit to the coastal communities surrounding the lake. State and provincial natural resource departments manage this resource through regulations on catch limits and size restrictions, ensuring the sustainability of the salmon populations and the recreational fishery they support.