Maybe some are fast track growth but I assure you that allot of the large lake trout are ancient as well. When you see a potbelly pig with tiny head yeah a younger fast tracker. The old big headed with large yellow fins and tails are a different animal , no need to kill them or the fast trackers, these are special fish that most people spend thousands of dollars on trips to Canada.
One could also say that a lot of the small (20") lake trout are ancient too.
Assumptions aside -- we KNOW that big fish are the result of
fast growth. Too many papers written on the subject to deny that.
The original report from this thread says: "...As you can see the fish was only 16 years old and you can see in its first 12 years it grew very rapidly.."
Just so we are all clear, this fish is the Utah state record @ 53lbs and 44" long!! It was only 16 years old! That is FAST GROWTH, not old age.
Take a look at the attached article, then compare the otolith from the orignal post:
The fish grew quickly for the first 3 years, probably to about 20". At this point, the growth slowed. Why? Because the fish was still eating a mix of other fish + other aquatic forage. For the next 4 years the fish grew slowly. At age 7, and probably at about 24", the growth increased again. Why? Most likely because the fish made a switch from a "mixed" diet to a diet of strictly fish only. Until this conversion happens, lake trout stay "small". So, at year 7 the growth increased again for the next 5 years. This matches exactly with the attached report, where the fastest growth rates observed were with fish between 25 to 30 inches (look at years 8-9!). This fish exploded in size from somewhere around 24" - 40" between the age of 7 - 11! That's amazing! And this fish was nowhere near being "ancient".
It shouldn't be assumed that this example would be an exception,
but rather the norm. This is the problem with using an "average" to attempt to determine the growth of fish. If you average it out, you don't see those periods of fast growth. Over time, as the fish gets older, that average per year will shrink more, and more, and more -- diluting the phenomenal growth that this fish actually experienced, and giving anglers the false assumption that big fish are the result of old age. This thinking is more in line with how mammals grow (determinate), not how fish grow (indeterminate).
The person that caught this incredible fish made another comment, particularly noteworth:
"... over all the lake trout in flaming gorge are growing much faster than people think and it wont ruin the lake if a few bigger fish are harvested for someone to enjoy on the wall."
Agreed 100%.
I have another article titled "A 4-step method to manage for quality fishing. It is too large to attach (1.2mb), but it explains these concepts. I'd be happy to send to anyone that wants to see it.