To understand the cold water period it is important to have some idea of the physics of water and the habits of bass, or what bass are besides being a fish.
First a bass is a cold blooded animal that can't control its core body temperature The water temperature that surrounds the bass will be the basses core temperature. The bass metabolic rate decreases with body temperature and will cease to eat, the fish will die at 40 degrees for all bass, except Florida LMB cease to eat at 45 degrees. Bass are sunfish and require warm water to be active. Therefor during the cold water period bass will seek the warmest water available that contains sufficient dissolved oxygen levels (DO) and prey.
The dynamics of water is interesting and the one factor we need to remember is water gets heavier, more dense, as it get colder until it reaches 39.4 degrees, then water gets lighter, less dense, until it freezes at 32. Why is this important? It prevents lakes from freezing bottom to top! The outside air temperature regulates the surface water temperature, as the air cools the surface water cools and begins to sink down though the warmer water below. The deeper the water is during the summer warm water periods the colder the water became, now the upper warmer layers are being cooled by cold air and the heavier surface water is pushing down on and through the upper warmer layers. The temperature zone between the deep cold water and upper warm water is known as the thermocline. Bass and baitfish are now forced to seek warmer deeper water and move down towards the thermocline. The deeper cold water fish like trout and bottom dwelling bait fish like sculpin and suckers move up through the water column to seek higher level of DO and the cooler upper layer water. The active ecosystem is changing and coming together around the thermocline, the life zone. As the days become shorter the air is cooling to near freezing temperatures, however life below the surface continues. Bass will be less active when the core water temperature in the warmest zone goes below 50 degrees. Shad start to die off and crawdads go into hibernation at 55 degrees, so cold water bait fish become the targeted prey in lakes where the core water temperature drops into the 40's.
Presentations need to target slower moving less active bass and resemble the prey sources available. Vertical spooning, drop shot, jigs and small plastic worms and slow moving spinner baits work well. Remember bass can take about 1 atmosphere pressure change or 15 feet easily and 2 atmosphere before having air bladder expansion problems. A bass neutralized to 30 foot depth can and will go to the surface to catch a meal and return. Late afternoon warming periods can activate a bass to move up to feed, slower moving surface lures like dog walking top water baits and jerk baits can and will produce strikes, if the bass are active. Bass can also move down to feed, so that why I target the 30 to 40 foot zone during the cold water periods. You will need to read sonar to determine where the bass are and where the life zone is by metering the bait fish, thermocline and actual fish echos. Active bass are usually near structure, within 5 feet, not suspended off it in deep water. Watch fish eating diving birds like grebes or comerants to determine bait fish school locations and direction the schools are moving. Outside structure like under water islands or humps, long major deep points, river or creek channels and saddles are primary winter period locations. Deep grass that survives cold water is a good location, however the heavier leaf weeds should have died off in cold water, if there is still a weed line give it try. Good luck.
Tom
ps; please feel free to ask questions about the calendar periods. When there is few responses than I can only assume there is little interest in this type of information or I have made too difficult to understand.
First a bass is a cold blooded animal that can't control its core body temperature The water temperature that surrounds the bass will be the basses core temperature. The bass metabolic rate decreases with body temperature and will cease to eat, the fish will die at 40 degrees for all bass, except Florida LMB cease to eat at 45 degrees. Bass are sunfish and require warm water to be active. Therefor during the cold water period bass will seek the warmest water available that contains sufficient dissolved oxygen levels (DO) and prey.
The dynamics of water is interesting and the one factor we need to remember is water gets heavier, more dense, as it get colder until it reaches 39.4 degrees, then water gets lighter, less dense, until it freezes at 32. Why is this important? It prevents lakes from freezing bottom to top! The outside air temperature regulates the surface water temperature, as the air cools the surface water cools and begins to sink down though the warmer water below. The deeper the water is during the summer warm water periods the colder the water became, now the upper warmer layers are being cooled by cold air and the heavier surface water is pushing down on and through the upper warmer layers. The temperature zone between the deep cold water and upper warm water is known as the thermocline. Bass and baitfish are now forced to seek warmer deeper water and move down towards the thermocline. The deeper cold water fish like trout and bottom dwelling bait fish like sculpin and suckers move up through the water column to seek higher level of DO and the cooler upper layer water. The active ecosystem is changing and coming together around the thermocline, the life zone. As the days become shorter the air is cooling to near freezing temperatures, however life below the surface continues. Bass will be less active when the core water temperature in the warmest zone goes below 50 degrees. Shad start to die off and crawdads go into hibernation at 55 degrees, so cold water bait fish become the targeted prey in lakes where the core water temperature drops into the 40's.
Presentations need to target slower moving less active bass and resemble the prey sources available. Vertical spooning, drop shot, jigs and small plastic worms and slow moving spinner baits work well. Remember bass can take about 1 atmosphere pressure change or 15 feet easily and 2 atmosphere before having air bladder expansion problems. A bass neutralized to 30 foot depth can and will go to the surface to catch a meal and return. Late afternoon warming periods can activate a bass to move up to feed, slower moving surface lures like dog walking top water baits and jerk baits can and will produce strikes, if the bass are active. Bass can also move down to feed, so that why I target the 30 to 40 foot zone during the cold water periods. You will need to read sonar to determine where the bass are and where the life zone is by metering the bait fish, thermocline and actual fish echos. Active bass are usually near structure, within 5 feet, not suspended off it in deep water. Watch fish eating diving birds like grebes or comerants to determine bait fish school locations and direction the schools are moving. Outside structure like under water islands or humps, long major deep points, river or creek channels and saddles are primary winter period locations. Deep grass that survives cold water is a good location, however the heavier leaf weeds should have died off in cold water, if there is still a weed line give it try. Good luck.
Tom
ps; please feel free to ask questions about the calendar periods. When there is few responses than I can only assume there is little interest in this type of information or I have made too difficult to understand.
