I think a lot of the shallow bog type ponds are going to take a real beating this winter. Once the ice is out 
I think we are in for quite the shock! 
It has happened during winters less severe than this one. I hope not, but I'm not very optimistic at this point.
I think we are in for quite the shock! It has happened during winters less severe than this one. I hope not, but I'm not very optimistic at this point. 
Winterkill
The Winter Oxygen Cycle
During winter, contribution of oxygen from photosynthesis by green plants and algae is greatly reduced. This is caused by the normal fall die-off of plants and algae due to cold water. Additionally, those green plants that remain produce less oxygen because their metabolism slows in cold water. This does not mean that oxygen levels are much lower in winter. In fact, the reverse is true. In unfrozen ponds, high oxygen levels will occur during winter because the oxygen needs are less in cold water. Aquatic animal (primarily fish) metabolism and oxygen-consuming decomposition processes are greatly reduced in cold water. Also, cold water contains more oxygen than does the warm water of summer. The strong winter winds also keep the pond water circulating and continually add oxygen during winter. These factors combine to prevent winterkill in unfrozen ponds even though plants are contributing little oxygen during winter. Problems, if they are to occur, will happen once ice forms on the pond.
How Winterkill Occurs
Winterkill is the result of a significant decline in oxygen during a long period of ice cover. Figure 1 illustrates the sequence of events that can lead to winterkill. As long as the pond is open or partially open, oxygen levels remain high. This is because diffusion of oxygen from the air and wind agitation add more oxygen to the water than is used for animal metabolism and plant decomposition. This is even true for those very sheltered ponds that receive very little exposure to wind.
When ice forms, neither wind nor diffusion from the air contribute oxygen to the water. The sole source of oxygen becomes the small amount produced by the few remaining algae and plants. If the ice remains thin and clear, oxygen production by plants and algae can continue as enough sunlight can filter through the ice to allow photosynthesis to occur. This production can nearly compensate for that which is used by respiration and decomposition that is continually ongoing. If the ice remains into mid-winter or thickens slightly, oxygen levels will begin to decline by 1-2 parts per million. This is because each day the pond plants and animals use slightly more oxygen than is produced. At this point, however, the pond still has sufficient oxygen.
A serious problem develops when ice persists into late winter and thickens considerably or worse yet, is covered by snow. This reduces the amount of sunlight reaching the plants and algae, thereby substantially reducing the amount of oxygen produced. Since metabolism and decomposition continue unabated, oxygen levels begin to drop and can approach levels that threaten fish survival. In cold water, oxygen levels less than 2-3 ppm for an extended time will begin to kill fish. If levels drop to 1-2 ppm or lower throughout the pond, a complete fish kill will result.
The Winter Oxygen Cycle
During winter, contribution of oxygen from photosynthesis by green plants and algae is greatly reduced. This is caused by the normal fall die-off of plants and algae due to cold water. Additionally, those green plants that remain produce less oxygen because their metabolism slows in cold water. This does not mean that oxygen levels are much lower in winter. In fact, the reverse is true. In unfrozen ponds, high oxygen levels will occur during winter because the oxygen needs are less in cold water. Aquatic animal (primarily fish) metabolism and oxygen-consuming decomposition processes are greatly reduced in cold water. Also, cold water contains more oxygen than does the warm water of summer. The strong winter winds also keep the pond water circulating and continually add oxygen during winter. These factors combine to prevent winterkill in unfrozen ponds even though plants are contributing little oxygen during winter. Problems, if they are to occur, will happen once ice forms on the pond.
How Winterkill Occurs
Winterkill is the result of a significant decline in oxygen during a long period of ice cover. Figure 1 illustrates the sequence of events that can lead to winterkill. As long as the pond is open or partially open, oxygen levels remain high. This is because diffusion of oxygen from the air and wind agitation add more oxygen to the water than is used for animal metabolism and plant decomposition. This is even true for those very sheltered ponds that receive very little exposure to wind.
When ice forms, neither wind nor diffusion from the air contribute oxygen to the water. The sole source of oxygen becomes the small amount produced by the few remaining algae and plants. If the ice remains thin and clear, oxygen production by plants and algae can continue as enough sunlight can filter through the ice to allow photosynthesis to occur. This production can nearly compensate for that which is used by respiration and decomposition that is continually ongoing. If the ice remains into mid-winter or thickens slightly, oxygen levels will begin to decline by 1-2 parts per million. This is because each day the pond plants and animals use slightly more oxygen than is produced. At this point, however, the pond still has sufficient oxygen.
A serious problem develops when ice persists into late winter and thickens considerably or worse yet, is covered by snow. This reduces the amount of sunlight reaching the plants and algae, thereby substantially reducing the amount of oxygen produced. Since metabolism and decomposition continue unabated, oxygen levels begin to drop and can approach levels that threaten fish survival. In cold water, oxygen levels less than 2-3 ppm for an extended time will begin to kill fish. If levels drop to 1-2 ppm or lower throughout the pond, a complete fish kill will result.
Good info kman! I knew somebody would want an explanation. As you can see the conditions are perfect for a major kill! I think that shallow ponds that have survived kills over the years are in serious trouble this year. Ponds without any moving water especially. It is not going to be a pretty sight after ice out! Which by the way, may not happen before April 1! 
I was wondering how thick the ice and snow pack are out on some ponds? any Ice fisherman want to chime in would be nice to know how thick different ponds are. How much snow pack and how much real ice under the snow pack. I have no idea as I hate winter and wont go outside unless I am getting paid or cursing and flipping out as i shovel and snow blow the driveway.
Last winter was just as bad. The snow pack this year is worse, but I think ice out will be around the same time. I noticed a die off at few places that I fished in the spring. A good way to tell is to go ice fishing and see how long your minnows are surviving. If they only last a few minutes than there is not enough oxygen.
This is natural and will happen to most bodies of water at some point. The good (or bad depending how you look at it) news is that there will be less weeds the following year.
A lot of people blame over fishing on why their honey hole sucks, but its not always the case. All lakes have good and bad years, and weather plays a key role.
This is natural and will happen to most bodies of water at some point. The good (or bad depending how you look at it) news is that there will be less weeds the following year.
A lot of people blame over fishing on why their honey hole sucks, but its not always the case. All lakes have good and bad years, and weather plays a key role.
i fear for my cranberry bog honey holes
Nate Karl (kman) and I were talking about this last week. It is a real concern and I think everyone who fishes these types of waters are holding their breath and keeping their fingers and toes crossed! Good luck with your places!
Keep in mind that most ponds were ice free into January this year so we had a late start to the ice. Just Thinking Positive !!!
It's not the late start that is the major factor. Read the last paragraph of kman's post. Hopefully if it does happen it won't be bad but the potential for a disaster of a spring is certainly there!
I was wondering how thick the ice and snow pack are out on some ponds? any Ice fisherman want to chime in would be nice to know how thick different ponds are. How much snow pack and how much real ice under the snow pack. I have no idea as I hate winter and wont go outside unless I am getting paid or cursing and flipping out as i shovel and snow blow the driveway.
The shallow (5 feet max) pond near near me has about 15-20 inches, some of which is layered slush. Either way, thats thick for a pond with an average depth of 3 feet.