A study to determine changes in pond bottom soil composition has been in progress on the Marion, Alabama National Fish Fatchery for more than ten years. This report gives the findings of analyses for calcium, phosphorus, potassium, pH, nitrogen and organic carbon. Samples were taken periodically from the same locations with the last ones taken ten years after the initial flooding. During the period, pH changed from acid to neutral levels generally. Phosphorus increased in some ponds and decreased in others. One pond which unfertilized supported a luxuriant growth of Najas sp. and Chara sp. even though no available phosphorus was measured in the soil sample. Organic nitrogen and carbon increased appreciably with nitrogen increasing at a greater rate. The carboni nitrogen (C/N) ratio became narrower in 11 of 12 ponds.
