Fish Wintering Habits

Fish Wintering Habits

By Ben Leal

By the time February rolls in we are well versed in angling experience. We think we have the fish figured out and locked in. Then, for some unknown reason, the fish move off our spot and seem harder to find. Weather can play a role in how fish react, either they are aggressive eaters or tight-lipped and fussy. Incoming low-pressure systems that signal a coming storm will tend to make the fish more aggressive and the opposite is true when a high-pressure system comes in signaling clearing skies and plenty of sunshine.

The one question remains though…when we have a pretty steady weather pattern and fish seemingly seem to disappear, where do they go? It’s clear that the weather hasn’t affected them so what made them move off and seek other areas of the lake to hang out. The short answer? It’s what’s happening beneath the ice as the season progresses that will make the fish move off. The long answer? Well, we’re going to dive right into that one.

Winters Blanket
Like any living organism, from people to any species of plant or animal, an organism or population, winter creates limiting factors in living conditions. As humans, we shelter inside nice warm houses, drive to and from work in warm cars and work in warm environments, for the most part. But when the snow flies or the temps dip well below the freezing point, that limits some of the things we do. The same goes for plants and animals to include the fish we love to chase after in the winter.

Fish cope with water temperatures that rarely rise about the 35-degree mark under the ice. It’s not the snow or ice or cold that is a limiting factor for fish, but rather the lack of oxygen. I’ve mentioned this in a few of the articles I’ve written about for open water and the same holds true for wintering waters. Dissolved Oxygen (DO) – is the amount of gaseous oxygen (O2) dissolved in the water. Oxygen enters the water by direct absorption from the atmosphere, by rapid movement, or as a waste product of plant photosynthesis.  Water temperature and the volume of moving water can affect dissolved oxygen levels. Oxygen dissolves easier in cooler water than warmer water.

Adequate dissolved oxygen is important for good water quality and necessary to all forms of life.   Dissolved oxygen levels that drop below 5.0 mg/L cause stress to aquatic life. Lower concentrations cause greater stress.  Oxygen levels that go below 1-2 mg/L for a few hours may result in large fish kills.

Generally, cold water holds more DO than warmer water. So why then is it a concern in the winter since the water is really cold? During the open water season, there’s nothing covering the water. Wind, waves and current are constantly mixing air in the water, dissolving oxygen into it. Plants also produce oxygen underwater through photosynthesis. Things change though as ice caps the lakes and snow blanket the hardwater covering the lakes. You no longer have wind, waves or current to oxygenate the water. And as snow covers the lake underwater plants will produce little to no oxygen. Those plants that help in the summer warmer months actually use oxygen up as they die and decompose; they actually consume dissolved oxygen.

Survival Strategies
As winter wears on fish and other aquatic animals use up the dwindling levels of DO and food supply. In many cases, depending on the amount of snow covering the lake, these aquatic inhabitants can spend up to six months in semi-darkness. Conserving energy is the key to survival. One behavior that fish employ to survive winter conditions is to change their living habits. Metabolic rates change and some physiological changes take place as well. Some fish, like the smallmouth bass rarely feeds when the water temps drop below 40 degrees. Fish become lethargic and sluggish and consume less and less food. The food that they do consume, some of the forage minnows and aquatic insects will move to where there are greater levels of DO in the water. Hence the reason why you’ve suddenly come upon a ghost town as you open a hole in your favorite spot that you swore was on fire last week.

Fish will also move into deeper parts of the lake where greater concentrations of DO is present. Aquatic insects also find their way to deeper haunts as they use the soft muddy bottom to winter in. Where the food goes so goes the fish!

The Chase
We all enjoy chasing after crappie and bluegill in the winter. Many ice anglers are also open water anglers, like me. As I’m chasing after some of my favorite summertime quarry, mainly largemouth bass, bluegills tend to nip and my plastics soon become a nuisance. Ahhh, but here we are, hardwater season, all of a sudden that 8-inch bluegill tugging on that short rod becomes a 10-inch one pound specimen. Our perceived hardwater fish seem brawnier than the aforementioned nuisance.

As winter wears on the key to finding active fish is determining areas that may still have decent vegetation or weedbeds. Using today’s modern electronics you can tell if there is a weedbed still standing by some of the marks you see on your sonar devices such as a Vexilar or Marcum unit. Those that employ cameras can easily detect where the weeds are still present and likely when those are found fish will not be far off.

As February begins to give way to March we’ll start to see some of that snow cover disappearing, which signals to fish that the long winter is beginning to lose its grip. Fish will then begin to move from deep wintering basin zones to pre-spawn staging areas. Truly the key to late ice is figuring out where the fish are moving to. Open water anglers that chase after bluegill and crappie may already have these areas marked on their electronics. Shallow weed flats especially those outside the mouths of bays are a great late-season ice spot.

Downsizing your baits will help increase your success during late ice as well. Remember that these fish have been feeding on small aquatic insects and minnows throughout the late season, matching your bait to some of the smaller prey they feed on will help. Tiny jigheads tipped with a waxworm or spike work well. If you can find spikes in red, even better; bloodworms start to make their presence known especially if you can find turbid water (an inflow from melting snow) which stirs up the sediment and brings in these tasty morsels to the fish. Small plastic baits will do the trick as well.

Knowing how fish react to these cold water conditions and some of the habits they have will help increase your late ice success. Remember to limit your catch, don’t catch your limit. The resources we enjoy today will only be as good tomorrow if we take care of them. Tight lines all!