Spring Trout Fishing | Water Temperature

Water temperature can have a tremendous impact on your trout fishing success. The encyclopedia defines Limnology as the scientific study of fresh waters, especially lakes and ponds, including biological conditions. Anglers should be concerned with one phase of this science, since knowledge in this field can enable fishermen to locate fish in lakes and ponds during the changing seasons.

Lakes that freeze over in the winter and grow warm in the summer undergo continuous temperature changes. And these water temperature changes vary considerably from top to bottom at certain periods. Trout are extremely sensitive to these temperature changes and amend their locations and feeding habits in response to these changes. Being aware of these conditions will enable the angler to fish the right place at the right time and will ultimately put more fish in the boat.

Trout avaoid extremes in water temperatures and position themselves in waters that offer ideal temperatures. If these temperatures are close to the surface, you will find fish feeding there. If the optimum temperature is close to the bottom, an angler must go deep to locate fish. It is at this ideal temperature that fish actively feed.

Optimum temperature for brown and rainbow trout is about 61 degrees. Brook trout prefer temperatures of 58 degrees, although suitable water temperatures in locating feeding fish will vary about 10 degrees above and below these marks.

The Thermocline

The particular location where fish actively feed is called the thermocline. The water temperature cycle in an inland body of water begins when it's ice covered. The principal factor in this cycle is that water reaches its maximum density at 39.2 degrees fahrenheit. Water is heaviest at this temperature. Water which is warmer or colder than this will rise to the surface.

Thus in the middle of winter waters at 39.2 degrees will be on the bottom, and the water above will be colder and lighter. When spring arrives a decided change takes place. The sun warms the water surface quickly and when the surface waters reach 39.2 degrees, they begin to sink, mixing with the lighter, colder water. At this point the lake is said to have "turned over".

The upper or warm water layer is known as the Epilimnion and the lower, cold water layer is termed Hypolimnion, with the thermocline sandwiched between. The thickness of these stratified layers of water vary with the size and depth of a given body of water.

The best way to locate the thermocline is to take the water temperature in your favorite lake at five foot intervals, until the level of rapid temperature drop is located. Once the thermocline is determined, you must get your lure or bait to that depth.

Trolling depth can be determined by trolling closer and closer to shore until your lure hangs up. Back the boat until it's over the lure. Mark the line at this point and you will be able to tell wjat depth you are at. From here you can determine if you must go deeper or troll at a shallower depth.

Shallow lakes do not contain a thermocline and in these areas, you should seek the spring-holes. In other lakes, perhaps only one small area contains a deep enough pocket for lake stratification.

It is in that pocket that you should concentrate your fishing activity. Game fish feeding habits are governed by a multitude of conditions including food, cover, water, etc. But the prime factor is water temperature.