Abstract
Sediment is important in the overall nutrient dynamics of water bodies. Nutrient exchange across the sediment-water interface of Shagari reservoir is an important process affecting the chemical composition and the trophic level, particularly in shallow parts of the reservoir. Comparison of nutrients in sediment and water for a period of one year was conducted. Water and sediment samples were collected monthly from six stations along the lake. Standard laboratory analysis was adopted and result obtained was subjected to statistical analysis at P<0.05. Surface water pH range from 6.3-8.1, while sediment pH was 6.2-7.6, surface water Electrical Conductivity ranged from 471.4-846.8 µscm-1 and sediment ranged from 197.6538.9 µscm-1. The nitrate-nitrogen recorded a mean of 1.29 mgl-1 in water while 0.25gKg-1 in sediment. Phosphorus was higher in sediment than in water, which recorded mean of 2.31gKg-1, while 0.18mgl-1 in water. All other chemical parameters were high in water, but low in sediment, with the exception of calcium which recorded mean of 0.75 gKg-1 in sediment and 0.50mgl-1 in water. This work therefore revealed that, sediment has more accumulation of important nutrients (such as phosphorus) than in water. This could be due to mineralization of organic matter that take place at the bottom of the reservoir.

Key words: Stations, Nutrients, Reservoir, Shagari, Sediment, Water