Re: 8/2-8/6/15 LL Valley-North Lake Off Trail Odyssey
Posted: Fri Jul 21, 2017 7:46 pm
I'll speculate. Feel free to disagree, agree, and or add your own two cents.
When the surface of an alpine lake is mostly ice, the reason it is so is more about the surface temperature being just below freezing still that tends to not melt ice. A lake covered by bright snow and ice, highly reflects sunlight back up into the atmosphere with little heating getting through the surface into lake water. Water in such lakes will be very still below the surface with thermoclines except where cold incoming streams flow at the bottom along channels towards a sumping low deep zone of a lake. When such a lake's surface begins melt off, it is usually at the edges where sun heated radiation off of shore rocks warms the near ice and especially where there is an incoming stream flow because although such streams may be cold snow melt runoff, they are likely not as cold as the lake water itself. As soon as the surface begins to show more open water the process accelerates because sunlight is then able to shine down into the lake water and warm it up.
By time an alpine lake surface finally freezes with coming winter, terrestrial insect sources have long gone leaving only sub-surface nymphs, amphibians, or smaller trout to feed on. I expect it does not take long before such sources become so limited that trout go into a long period of stupor, not feeding or moving. Trout need to have water flowing over their gills to breath. They cannot keep swimming all winter so instead find a location where incoming streams flow in channels along a lake bottom where they can just rest on the bottom pointing towards the stream flow. I have seen just this phenomenon at huge Marie Lake where several dozen brook trout were densely all laying down on the bottom where a small stream flowed in and not moving for hours in some kind of stupor. And average size was 11 to 14 inches. Note that lake also has rainbow and goldens.
Now what may occur in a lake that is just coming out of ice break up is most trout are still cold in the stupor mode. After most of the surface ice melts, winds causes a sudden increase in lake water movement that upsets the static thermoclines and tends to stir the fish into moving about. That is when they are like us waking up in the morning...hungry. So there is probably a window for trout to be especially hungry, but it doesn't start while an alpine lake just shows a few open areas.
David
When the surface of an alpine lake is mostly ice, the reason it is so is more about the surface temperature being just below freezing still that tends to not melt ice. A lake covered by bright snow and ice, highly reflects sunlight back up into the atmosphere with little heating getting through the surface into lake water. Water in such lakes will be very still below the surface with thermoclines except where cold incoming streams flow at the bottom along channels towards a sumping low deep zone of a lake. When such a lake's surface begins melt off, it is usually at the edges where sun heated radiation off of shore rocks warms the near ice and especially where there is an incoming stream flow because although such streams may be cold snow melt runoff, they are likely not as cold as the lake water itself. As soon as the surface begins to show more open water the process accelerates because sunlight is then able to shine down into the lake water and warm it up.
By time an alpine lake surface finally freezes with coming winter, terrestrial insect sources have long gone leaving only sub-surface nymphs, amphibians, or smaller trout to feed on. I expect it does not take long before such sources become so limited that trout go into a long period of stupor, not feeding or moving. Trout need to have water flowing over their gills to breath. They cannot keep swimming all winter so instead find a location where incoming streams flow in channels along a lake bottom where they can just rest on the bottom pointing towards the stream flow. I have seen just this phenomenon at huge Marie Lake where several dozen brook trout were densely all laying down on the bottom where a small stream flowed in and not moving for hours in some kind of stupor. And average size was 11 to 14 inches. Note that lake also has rainbow and goldens.
Now what may occur in a lake that is just coming out of ice break up is most trout are still cold in the stupor mode. After most of the surface ice melts, winds causes a sudden increase in lake water movement that upsets the static thermoclines and tends to stir the fish into moving about. That is when they are like us waking up in the morning...hungry. So there is probably a window for trout to be especially hungry, but it doesn't start while an alpine lake just shows a few open areas.
David