1. Nutrient Input and Eutrophication 1 Agricultural activities and sewage add nutrients, as well as disease organisms, to marine environments

2. Nutrient Input and Eutrophication 2 Agricultural activities and sewage add nutrients, as well as disease organisms, to marine environments Eutrophication is the addition of dissolved nutrients to a water body, resulting in large increases of phytoplankton production

3. Nutrient Input and Eutrophication 3 Eutrophication sources from land: 1.Point sources such as sewage treatment outfall pipes 2.Point sources such as sewer overflows, which may be connected to sewage systems (Combined Sewer Outflows or CSOs) 3.Commercial fertilizer used in agriculture - can be in runoff - non-point source

4. Nutrient Input and Eutrophication 4 Eutrophication sources from land: 1.Point sources such as sewage treatment outfall pipes 2.Point sources such as sewer overflows, which may be connected to sewage systems (Combined Sewer Outflows or CSOs) 3.Commercial fertilizer used in agriculture 4.Animal waste in “lagoons,” connected to waterways

5. Typical Urban Solution - When it rains, pollution spills over into estuary Rain water Nutrient Input and Eutrophication 5

6. Nutrient Input and Eutrophication 6 Atmospheric sources: 1.Aerosols from agricultural fertilizer 2. Nitrogen oxide deposited as nitrates on coastal ocean from fossil fuel emissions

7. Nutrient Input and Eutrophication 7 Atmospheric nitrate 25% Fertilizers 34% Point Sources 23% Atmospheric ammonium 14% Animal waste 4% Contributions of nitrogen to Chesapeake Bay watershed

8. Nutrient Input and Eutrophication 8 Effects of Eutrophication: Development of Hypoxia 1.Nutrients stimulate phytoplankton growth 2.Not all phytoplankton is grazed 3.Bacteria consume dead phytoplankton 4.Oxygen declines 5.If water is stratified or circulation is sluggish: benthic animals die (or emigrate) owing to oxygen loss

9. Development of hypoxia

10. Nutrient Input and Eutrophication 9 Treatment of Sewage: 1.Primary treatment - solids intercepted by screens 2.Secondary treatment - more toxic nitrogenous compounds and colloids are stirred in aerobic tanks so that only phosphates, nitrates, ammonium released in coastal water 3.Tertiary treatment - dissolved phosphates, nitrates, and ammonium removed (use of chemical techniques, microbial approaches to remove N compounds)

12. Nutrient Input and Eutrophication 10 Treatment of Sewage: Objective of primary treatment: to reduce organic material input, to reduce Biological oxygen demand (BOD) Primary treatment has been successful in the increase of dissolved oxygen in polluted water bodies such as New York Harbor

13. Nutrient Input and Eutrophication 11 BOD Loadings from NYC (metric tons/day) % Oxygen Saturation Relation of input of organic solids to oxygen in water - NY Harbor