The concentrations of Cu, Zn, Pb, Cr, Fe, Mn, and Ni and other sediment quality parameters (percentage of organic matter, calcium carbonate, total carbon, total nitrogen, and total phosphorus) were investigated seasonally in Lake Uluabat (Turkey) sediments (to reveal the sources of biological material and to determine the effect of the settling particle compositions on heavy metal transport. Examination of seasonal variations and correlation coefficients calculated among the parameters showed that settling biological material was an important carrier phase, especially for Cr, Cu, Pb, Fe, and Mn. The metals and nutrients in the lake could come from the same pollution sources. According to the C:N:P ratios of the sediments, it was discovered that biologic materials originated from algae population and domestic and industrial wastewaters. Iron and manganese cycling was also a contributor to trace element transport, while calcium carbonate formations were determined to be inefficient carrier material.