Tuesday, September 7, 2010
Let’s get to know…The Mackinaw (Or Lake Trout)
How cool are fish? Each species is different and has biological differences that control so much about where they live and why. Knowing these facts will help dial in the location and patterns of the fish you seek to catch. Fish identification is just the start. Learning the biological aspects helps us catch and preserve this amazing natural creature. Please bare with me and my poindexter excerpts of “Let’s get to know…”.
Let’s get to know The Mackinaw (Or Lake Trout)
One of the largest trout species in North America is the Mackinaw or Lake Trout as it is commonly called. This species of fish is actually a member of the char family and can reach upwards of 50lbs in Colorado. The state record being set in 2007 by D. Walker at 50.35lbs and 44.25 inches in length (Blue Mesa). How impressive is that?
A deeply forked tail is the first distinguishing mark. The overall coloring is dark silver with light spots. The fins will have a narrow white line similar to brook trout but not as defined.
In Colorado lake trout prefer deep, clear water with average water temperatures of 50 degrees and will die in water temperatures over 75 degrees. These fish feed on most anything and can have a wide-ranging diet including their own species. In large lakes the lake trout will prefer to feed on other fish as where in the northern territory rivers and streams the lake trout will rely more on insects and crustaceans as that is what is more available.
Lake trout spawn in fall and normally reproduce every second year from September to November in most parts of their range. This species prefers to spawn on rock structure in close proximity to the shoreline depending on conditions. Females typically release 1600-3600 eggs per pound. Eggs hatch within four to five months depending on conditions. Light and wind factors play a large part in lake trout spawning. Lake trout don’t form mating pairs or construct redds like other salmonids. Eggs may be fertilized by one or more males and when they hatch the fish have to absorb the yolk sack for several weeks before fully emerging. Then the tiny buggers have to reach the water surface to fill their swim bladders before diving down to deeper, cooler waters.
The lake trout are one species of fish that is greatly controlled by water temperature. These fish will favor specific depths that relate directly to the water temperature of that area. Lake trout will move up and down the vertical spectrum feeding in the water with the ideal temperature in the shallowest water they can tolerate. Preferring colder temps, the macks don’t generally move into shallower water until late fall.
No love for trophy Mack fishing in Colorado
The regulations and management for the lake trout in Colorado is pretty lenient on the take side. In waters where Kokanee and rainbow trout may be favored there are no limits on size or number of fish and anglers are encouraged to keep all lake trout they catch. This management is meant to keep the lake trout viable in the system without displacing the other species. But this is not a very controlled method and results may vary greatly to one side or the other. It also does little to safeguard or promote a trophy mack population. Compounded with sponsored lake trout ice fishing tournaments and netting during spawning seasons, the deck is stacked heavily against this species. Big predator fish spark a lot of controversy in Colorado and there are good arguments on both sides of the fence. Hopefully anglers and officials can meet in the middle and safeguard a few places for big macs.
Some crazy cool facts about Mackinaw trout:
Lake trout are negatively phototropic; they avoid light.
Lake trout spawn at night.
Lake trout may not spawn every year, and northerly stocks tend to have fewer spawning fish in any one year. This is thought to be a function of photoperiod, shorter growing season, less abundant food, and the unproductive nature of many northern lakes.
In large bodies of water such as the Great Lakes, lake trout may migrate up to 300 km (186 mi) to their spawning grounds.
Lake trout scales are unreliable for aging purposes because the annuli cannot be distinguished. Researchers determine age by reading otoliths, which are calcified tissues of the inner ear used by fish for maintaining equilibrium and balance. The oldest fish on record, taken in the Northwest Territories, was aged at 65 years.
Female lake trout are crossed with male speckled trout to produce a fish known as splake, in a process called artificial hybridization. Hatcheries produce splake because this hybrid grows very quickly.
Good luck and Good Fishing
Acknowledgements and references below:
Posted by Coloradocasters