Phosphate Absorption in Eelgrass1

The absorption of phosphate by eelgrass ( Zostera marina L.) was studied using 32 P in a partitioned container where leaves were separated from roots and rhizomes. Absorption, which was greatest in the light, occurred through both leaves and roots, and the absorbed phosphorus was transported rapidly to all parts of the plant. It therefore appears that eelgrass can use phosphate from sediments and from water. Phosphate removed from solution by the roots and rhizomes was returned in part to the surrounding water through the leaves, suggesting that in nature seagrass may act either as a sink or as a source for dissolved phosphorus in estuarine waters.