The influence of the thermocline on fish behavior
The thermocline is the layer of water in which the temperature differs from temperatures below – and overlying layers. The thickness of the thermocline can vary from several to tens of meters. The science of the thermocline is divided into the deep and seasonal. Deep water can be up to a thickness of two kilometers. His existence constantly. The seasonal thermocline appears and disappears throughout the year, for example, by melting ice.
The fishermen use to find fish quality fish finder that can show on the display area of the thermocline, know that the fish is almost always above it. The fact that the temperature gradient within the thermocline may be 10 degrees per meter of thickness. For most underwater creatures crossing this zone is shocks. It is no coincidence that fans of breeding aquarium fish, transplanting them from tank to tank, always ensure that the temperature there was the same. However, there are species of fish for which the thermocline is not an insurmountable barrier, for example, vendace, smelt.
Much more than temperature rise, the disadvantage of fish is oxygen deficiency, which is installed both in the thermocline and below the overlying layers.
The oxygen saturation of the water occurs in the process of photosynthesis of plants in the pond, as well as from atmospheric air through the surface of the water. Clearly, both of these processes operate exclusively in the area overlying thermocline. Under it there is almost no photosynthesis – dark. The oxygen that got into the lower area in the period before the rise of the thermocline, in the spring is spent on breathing bottom dwellers and the processes of rotting of bottom plants and organisms. And the higher the water temperature, the decay processes are faster. As a result, in reservoirs with a stable thermocline, both in itself and in the underlying water layers occurs very unfavorable for fish oxygen deficit. Only this factor is the main reason because of which fish are leaving the area below the thermocline.
It is important to keep in mind another feature of the thermocline, namely, on the line of the thermocline, which show the modern sonar is not affected by the bottom topography. And fish is very important.
As already known, due to lack of oxygen in a zone below the thermocline fish kept above its border. For walleye, pike, bream is an unnatural position. And if the bottom of the reservoir has raised over termoklina areas, these places become places of a congestion of fish. Here fishing is always the result.
Summarizing a conversation about the thermocline and its impact on fishing during the hottest time of the year we can say that the temperature stratification of the water should definitely be kept in mind when defining fishing tactics. And if there is no sounder with termoemcali, at least underwater thermometer.