Effect of algal bloom deposition on sediment respiration and fluxes

Total carbon dioxide (CO2), oxygen (O2), dissolved organic nitrogen, ammonium and nitrate fluxes in sediment-water interfaces were measured to determine the influence of algal deposition on sediment respiration and nutrient dynamics. Results showed that the algal layer increased CO2 and O2 uptake indicating an increase in respiration rate. Nitrogen flux was likewise enhanced, and this might have been caused either by the elevation of denitrification rates or the inhibition of nitrification. On the other hand, phytoplankton sedimentation decreased ammonium efflux. The inorganic nutrient fluxes reverted to normal levels after algae decomposition.