North 40 Fly Shop eMagazine March 2018 | Page 64

photosynthesis to produce lush submerged and emergent green plant growth. This organic matter provides the habitat for many trout food sources as well as providing cover for juvenile trout. Each winter, the decomposing vegetation provides the nutrients for the next season of plant growth. The typical small lake is shaped like a dinner plate with shallow edges sloping off into a deeper center area. The amount of shallow shoal area in relation to the deep water area gives a strong indication of relative productiveness. However there is a fine balance between the amount of shallow You can catch big trout from shore in British Columbia and other Pacific Northwest lakes. However, a boat allows you to access all areas of a lake and all depths. In addition, a boat allows you to use electronics, which helps you find fish quickly. water versus deep water area and survival of trout in lakes that endure months of ice cover and/or experience long hot, dry summer air temperatures. The drop-off is the transition zone between the shoal and deep-water areas of the lake. The slope of the drop-off can vary from very gradual to an abrupt angle almost approaching 90d degrees. The more gentle slopes offer more diverse fish and fish food habitat and fishing area for that matter. The drop- off plays a crucial role during warm water periods as the water temperatures drop significantly over a short vertical distance and provide a refuge for trout that seek cooler more oxygenated water. Beyond the drop-off is the limnetic or deepwater zone of the lake. The most productive stillwaters are seldom deep, usually with maximum depths of less than 20 meters. Some of the best western trout fisheries are less than eight meters in maximum depth. The most prominent trout food source found in the deep-water zone is zooplankton. Common zooplankton are the crustaceans Daphnia, Cyclops and Bosmina, which are all quite visible to the naked eye. Zooplankton gather in dense horizontal layers or bands in the water column and fish just swim through the masses for a nutritious and easily captured meal. This deeper water can also be a large refuge area for trout during the hot summer months. The abundant supply of tiny zooplankton in deep, cold water creates the situation known to anglers as the summer doldrums, where the fish are deep and gorging on food items that are difficult to imitate with a fly. The deepwater zone is