Distribution and Composition of Substrate in the Littoral Zone in Jackson Lake, Grand Teton National Park, Wyoming

The composition of sediments varies both horizontally and vertically in a lake. The distribution of sediment types is related not only to basin geomorphology, but also to the effect of turbulent water as it moves substrate particles in the littoral zone. Definite patterns of erosion and deposition in lakes have been described by many limnologists (e.g., Hutchinson, 1957; Spence, 1982; Keddy, 1982, 1983, 1984). Sedimentation and the quality of sediments as a nutrient source affect the ability of macrophytes to colonize and persist in the littoral habitat. The ability to root in a particular area is directly related to the extent which a substrate can anchor the potentially large plants (Spence, 1982). On erosional shores, suspended sediments abrade rooted plants and may cause damage and breakage. On the other hand, the macrophyte community stabilizes bottom sediments and their presence leads to increased water clarity as particulates settle out due to reduced water currents within plant beds. Since the relationship between plants and sediments is well known, our objective was to measure the distribution and composition of the sediments in the littoral zone of the lake. Then we could relate the distribution of substrate to the distribution we had measured for macrophytes in the littoral zone