Quantification and characterization of sedimenting particulate organic matter in a shallow hypereutrophic lake*

SUMMARY. Sedimenting seston was collected in May‐November 1976 and 1977 in sedimentation traps anchored 0.5 m above the pelagic sediments of hypereutrophic Wintergreen Lake. Sedimentation rates differed greatly in the two years studied, ranging from 2.7 to 19.3 g m −2 day −1 in 1976 and from 2.6 to 9.5 g m −2 day −1 in 1977. Because of the shallowness of the lake (maximum depth 6.5 m), the quantity and quality of sedimenting particulate organic matter (POM) was closely linked to the production dynamics of the phytoplankton. Chemical analyses indicated that the sedimenting POM was planktonic in origin and, in contrast to that of many deeper lakes, was dominated by protein. Short sedimentation distances coupled with the close proximity of the anaerobic hypolimnion to the photic zone ensured that the majority of sedimenting POM reached the sediments in a relatively undegraded form.