Historical changes in phosphorus accumulation in a small lake

T. E. Murray, Elizabethtown College
J. F. Gottgens, The University of Toledo


Isotopes like Pb and Cs are effective tools for determining chronology in lake sediments. Once the chronology is established, environmental changes in lakes can be investigated, and the causes for those changes can often be inferred. Pb and Cs profiles were constructed for the sediments of Crystal Lake, Connecticut, USA. The geochronology was used to determine the historical changes in organic matter and P accumulation in the sediment. Those profiles showed two significant periods of sedimentation which correlate with major precipitation events. Decreasing P accumulation in the sediments of the lake in the last decade was also correlated with increasing eutrophication as documented by increases in epilimnetic P and decreases in transparency. 210 137 210 137