Lake Trout (Salvelinus namaycush, Ojibwa: Namegos)
Largest of the freshwater char, these Superior predators sit atop the food chain, but the bulk of them live deep within the lake ... most of the time. The fats (siscowets), of which there are many, lounge in lightless zones lolling about in cold, oxygen-rich waters until hunger and dusk have some of them hunting kiyi and ciscoes closer to the surface. The leans are tasty ... maybe too tasty. Overfishing combined with the arrival of the vampirish sea lamprey sent Superior's lake trout populations reeling in the '50s. Now, there are leans and siscowets to spare, thanks to sea lamprey control and careful fisheries management.
Members of the char clan, lake trout can be found in Minnesota's northeastern lakes and Lake Superior. Fishermen and fisheries professionals talk mostly about two strains that make up the bulk of the lake trout in Lake Superior: leans and fats (a.k.a. siscowets). However, there are at least two other strains recognized: half-breeds and humpers (a.k.a. paperbellies).
More closely related to arctic char than they are to the Superior's introduced steelhead, lake trout prefer to live offshore in cool, deep waters; siscowets live even deeper than leans and often spend the day near the bottom of Lake Superior. In the Great Lakes, leans are usually found at depths between 100 and 300 feet.
In late September, lake trout move to spawning grounds in water shallower than 100 feet. Lake trout are known to return to the same spawning grounds every year. The male trout arrive before the females to clean the lake bottom of debris, algae, and slime. Males often remain near the spawning grounds for 3 weeks or longer, but leave after the spawning season.
Lake Trout in Lake Superior:
- They mostly prey on the opossum shrimp (Mysis), although they are also known to eat other crustaceans, insects, and midsize fish like cisco, kiyi and bloaters.
- Sea lamprey, an invasive parasitic fish, can kill lake trout. Lake trout are also eaten by humans.
- Adults typically grow to 15-20 inches.
- Adults weigh 7-12 pounds, although a 63 lb. 2 oz. trout was angled out of Lake Superior in 1952.
- They live about 12-16 years, but can survive up to 25 years.
Lake trout were once plentiful in Lake Superior. The population plummeted from overharvesting paired with predation by the non-native sea lamprey. Since 1952, chemical control of the sea lamprey, restocking, and ending commercial fishing have helped the lake trout recover. The siscowet populations have been more resilient than lean lake trout; some estimates place the number in Lake Superior around 100 million fish.
What do you get when you cross a lake trout with a brook trout? A splake! The splake is an omnivorous species that grows rapidly and matures rapidly (although it is less fertile than its parent species). Splake prefer to live closer to shore than lake trout, making them less susceptible to sea lamprey attacks.
- Species Profile: Lake Trout
- Lake Trout are Heart-Friendly (Seiche)
- Lake Trout and the Tao of Research (Seiche)
- Fish Sensory Systems
- Big Fat Lake Trout: Siscowet (5:14) (Audio)
- Siscowet Trout: A Plague of Riches (Seiche)
- Trout, Ciscoes, and Shrimp: News from the Serrated Edge of Science (Seiche)
- Let Em Down Easy: Returning a Fish to Deep Water (Seiche)
- Commercial Fishing: The Life, the Limits, the Lore (Seiche)
- Mapping the "Secret" Spawning Grounds of Lake Trout (Seiche)
- Stout Trout Eyed for Market (Seiche)
- Lake Superior Fish Recipes (Recipe)
- Truly Superior Fish Note Cards (Set 1) (Publication)
- Trout: MN DNR