All About Lake Trout

In the definitive book on salmonids, Trout and Salmon of North America, Robert Behnke opens his chapter on lake trout with a clear statement of this northern icon’s hold on anglers: “The lake trout has an almost fanatical following among anglers across North America.” That certainly would not be news to the anglers of Scott Lake Lodge.

Our anglers have been fanatics about lakers for years. It’s usually the first look at the massive head (typically 25% of the entire body length) that rattles the person on the other end of the line. Lakers aren’t just big: they’re cool. When you bring up a big one from the depths you know you are looking at the fasting thing in the lake. And the stubborn fight, displaying incredible stamina, is legendary. Salvelinus namaycush isn’t really even a trout: it’s a member of the char family, along with the arctic char, brook trout, bull trout and dolly varden. It gets its species name (namaycush) from the Cree word “namekos” meaning “dweller of the deep”.

 

Like all char the lake trout is a fall spawner and it is a North American original with the broadest distribution of any North American native salmonid. Its native range spans all of Canada right into the arctic islands. I have caught lake trout on Victoria Island at latitude of 72 degrees north. At this extreme edge of their range lakers get long but not fat. I recall one that came out of a rapids between two lakes that measured 44 inches but didn’t weigh 18 pounds, a real rail. In the US lake trout are native to the Great Lakes and selected deep lakes in the upper Midwest and New England where they are called “togue”. In the western US where they were introduced they are usually called Mackinaw trout or just Macks.

Their native range coincides neatly with the limit of the Pleistocene glaciations. It’s always been a cold water fish, preferring water temperatures around 50 degrees F which on Scott puts our lakers at depths of 50-150’ in summer. (Those depths sound extreme but lake trout were routinely netted on Lake Superior at depths of 600 feet or deeper.) At ice out in June and again in September, the cold water temps allow our lakers to roam the entire water column and they do, often entering the shallow bays of Scott where they can be caught sight casting. Lake trout need a lot of dissolved oxygen, about 4 parts per million, much higher than warm water lakes can maintain.

Lake trout grow slowly throughout their range but the far north they grow very, very slowly. But they compensate for slow growth by have incredibly long life spans. On Great Bear Lake in the Northwest Territories (NWT) where lakers have been studied extensively, it takes 20 years to make a two foot long lake trout. It’s not a lot different right at Scott Lake. In 2002 the lodge commissioned a study by the British Columbia Institute of Technology biologists to age our trout and pike. By removing a bony structure in the trout’s head (the otolith) researchers can firmly establish the age of a fish. Obviously it’s not a catch and release techniques so no trophy sized lakers were tested. One modest 24 incher proved to be 22 years old. Even trout in the 15” range were into their second decade of life. The oldest lake trout on record was a 62 years old trout from Kaminuraik lake in the NWT. Lake trout from Kaminuraik do not spawn until they are 19 years old.

But slow growth does not mean small size. While the average lake trout is around three to five pounds in the far north there are massive trout. The biggest on tackle was a 72 pound fish from Great Bear Lake. Just a few years ago a 70 pounder was caught on Tazin Lake, just 70 miles from Scott. Recently on Scott a trout of approximately 50 pounds was caught. There have been trout of over 100 pounds netted, one on Lake Superior and one just south of Scott on Lake Athabasca. That fish, netted in 1961, weighed 102 pounds but had a length of only 49.5”. It turned out to be an abnormal fish, a male whose testes failed to develop, allowing all of its food intake to be utilized for growth. There is an adage that it takes big lakes to produce big trout. That seems to hold up. Studies have indicated that in quality trout lakes the total biomass of lake trout will only be 2 to 4 pounds per surface area of lake. (The most productive brown or rainbow trout streams can produce 500 pound per acre by comparison.) It’s all about the limiting factor of the dissolved oxygen but that still leaves hundreds of thousands of pounds of trout in Scott Lake, plenty to go around.

To get so big trout have to eat a lot. That huge head features a giant mouth. Many anglers have gone weak in the knees when a white bucket opens up at the side of the boat after following the lure. That mouth is the gateway for a steady stream of food. As juveniles, trout feed mainly on invertebrates and insects. Opossum shrimp, found at depths in most northern Canadian lakes, are a mainstay of small trout. Even bigger trout though will take a snack of insects. On Scott during late June there is typically a heavy midge hatch on evening with no wind. Lakers up to two feet will be on the surface taking clusters of midges and can be caught on any dry fly attractor pattern. Years ago fishing in Ontario’s Quetico Provincial Park I was cleaning a three or four pound trout for dinner and found its stomach absolutely stuffed with ants. It was right after ice out and the lake trout on this lake must have been cruising the shoreline just sucking in ants. But typically once a laker is over two feet it’s a meat eater. And lakers are voracious predators. They can catch anything down there and they usually lunch on whitefish, lake cisco and burbot, along with smaller lake trout. The can and will take pike. Bringing in a medium sized pike on Dunvagen during the fall spawn, I had a huge laker T-bone the pike, maybe getting even for all the small trout that are taken by pike.

If lake trout are introduced to new lakes they can radically change the system. Lake trout stocked in Lake Tahoe totally wiped out the native Lahontan cutthroat trout, a fish that once grew to 40 pounds. Lakers unintentionally planted in Yellowstone Lake are threatening to wipe out the native cutthroat trout there. They can be pigs. All Scott guides have stories of big tails sticking out of laker’s mouths, usually whitefish or lake trout tails. That aggressiveness is why so many anglers, including many at Scott, just love lakers. Head guide Cory Craig captures the love affair with lakers with this description: “Big lakers are like sharks: they cruise out of the depths with their pectoral fins extended from their sides, giving them a big sweeping motion of their body, just like a shark. I even love watching Bubbles pick up belly meat under my boat or even out of my hand. She sweeps in just like a scavenging shark.”