Great Basin Naturalist


A common submersed aquatic plant of Great Basin wetland and riverine systems, Potamogeton pectinatus L. (sago pondweed) is a key waterfowl food. Nutritional qualities of submersed aquatics in the Great Basin are little understood. The purpose of this study was to determine the seasonal element cycling and nutritional qualities of P. pectinatus drupelet, leaf, and root tissues from the lower Provo River. Leaf tissues protein was 27% (dry weight) in July, but declined to 15% by December. Drupelet protein content was 9% in July and 6.5% in October. Lignocellulose in leaf tissue was lowest in July at 34% and increased as the season progressed. Percent fat was highest in leaf tissue at 12% in July. Sugars were highest in P. pectinatus leaf tissues in December and July. Calcium and magnesium concentrations increased in P. pectinatus tissues over the entire season. Leaf tissue zinc was 329 ppm (dry weight) in October. Leaf iron concentration was highest in September at 1184 ppm, while root tissue iron was 7166 ppm. Manganese content in leaf tissue peaked in October at 4990 ppm. Copper concentrations in leaves and roots were variable. High protein in leaf tissue would benefit local nesting and brooding waterfowl populations that feed on this aquatic. Trace metal concentrations in leaf and root tissues, from possible anthropogenic activities, appear very high during fall migratory months. Metal bioaccumulation by this species in other Great Basin wetlands and possible metal toxicity in waterfowl warrant further study.