A Summer Place
Like income tax returns, thermoclines confuse most bass fishermen--they understand the basic premise but not how these summertime phenomena interface with their efforts. A thermocline is a band of water in a lake where the temperature at the top of the strip begins to drop rapidly (about one degree per foot) and where the water at the bottom of the band is slightly warmer than the colder layer on which it floats. Below the thermocline is the hypolimnion, an area where dissolved oxygen at the lowest depths is inadequate for the survival of most fish. Above the thermocline is the epilimnion, an area of warmer water saturated by light. A shallow lake, like most in Florida, has no appreciable thermocline because there is very little difference between the temperature on top and the temperature on bottom. Thermoclines usually form at depths between 20 and 50 feet, depending on water clarity.