Survey of Fena Reservoir, Island of Guam: Limnological reconnaissance

During the limnological reconnaissance of Fena Reservoir, samples of the water columns and bottom sediment were obtained and analyzed at five locations within the reservoir. Major ion analyses of filtered surface water indicated that calcium and bicarbonate are the dominant cation and anion in the reservoir. Thermal stratification was recorded at all five locations. Temperature data indicated a distinct hypolimnion at three of the sampling locations below a depth of 8 meters. Vertical profiles of pH exhibited changes with depth as did conductivity. Marked clinograde distributions of dissolved osygen were evident at all but the shallowest locations. Inverse clinograde distributions of total phosphorus, dissolved nitrate plus nitrite and dissolved ammonia were observed at the two deepest stations. Total organic carbon had no distinct profile and had an average concentration of 13.8 milligrams per liter. Data are also provided for nutrient analysis of the sediment.