Eutrophication of water body

Eutrophication

1. Eutrophication of Water bodies Presented by Bandhu Pd. Bhandari Tallinn university of Technology Presented by Bandhu Pd. Bhandari

2. Table of contents Introduction Mechanism Process and stages Causes and sources Main consequences Negative impacts Management

3. Introduction The word “ Trophi ” in Greek means food or nutrient , whereas the words “ oligo ”, “ meso ”, “ eu ” and “ hyper ” stand respectively for rare , moderate , abundant and excessive . Therefore, the words oligotrophic , mesotrophic , eutrophic and hypertrophic have been used by biologists to describe the various nutritional statuses of a marine or fresh water environment. These words are used to describe the potentially available quantitative biomass .

4. Trophic level and status

5. Classification of lakes on the basis of nutrients content Oligotrophic lake - low in nutrients, Productivity is low, Many species, low populations, Nice clean water. Mesotrophic lake - intermediate levels of nutrients, Plankton is intermediate, Some organic sediment and moderately clear water. Eutrophic lake - rich in nutrients, low transparency, high plankton, less oxygen, and showing increasing signs of water quality problems. Hypertrophic lake - very high nutrient concentrations where plant growth is determined by physical factors. Water quality problems are serious and almost continuous.

6. Eutrophication Eutrophication is an accelerated growth of algae on higher forms of plant life caused by the enrichment of water by nutrients , especially compounds of nitrogen and/or phosphorus and inducing an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned. Human-caused, accelerated eutrophication is referred as cultural eutrophication .

7. Cultural Eutrophication

8. scenario leading to eutrophication The mechanisms that lead to eutrophication , i.e. to this new status of the aquatic environment, are complex and interlinked . The main cause of eutrophication is the large input of nutrients to a water body and the main effect is the imbalance in the food web that results in high levels of phytoplankton biomass in stratified water bodies. This can lead to algal blooms .

9. The process of Eutrophication

10. Causes of eutrophication and supporting factors The enrichment of water by nutrients can be of natural origin but it is often dramatically increased by human activities . This occurs almost everywhere in the world. main sources of nutrient input are: Runoff Erosion and Leaching from fertilized agricultural areas Sewage from cities and industrial wastewater Atmospheric deposition of nitrogen (from animal breeding and combustion gases) Other point and non-point sources of pollutants

11. Causes of eutrophication

12. Sources of cultural Eutrophication

13. Main consequences of eutrophication Availability of oxygen: low volume of oxygen due microbial decomposition & respiration and all life will disappear. very specific smell of rotten eggs , originating mainly from sulphur , will appear. Changes in algal population: Excessive growth of macroalgae , phytoplankton and cyanobacteria , algal bloom. Changes in zooplankton: decrease in fish and shellfish population, invertebrate etc.

14. Consequences cont. The direct consequence is an excess of oxygen consumption near the bottom of the water body. The ratio of nitrogen to phosphorus compounds in a water body is an important factor determining which of the two elements will be the limiting factor , and consequently which one has to be controlled in order to reduce a bloom. Generally, phosphorus tends to be the limiting factor for phytoplankton in fresh waters . Large marine areas frequently have nitrogen as the limiting nutrient.

15. Healthy system vs. Eutrophic system

16. Stages in Eutrophication Phytoplankton (low concentration) Phytoplankton (high concentration) Dead fishes and crustaceans Green filamentous algae Bottom anoxia Anoxic waters with H2S bubbles Epiphytes on focus Pristine situation Start of eutrophication Extreme eutrophication

17. Factors supporting the development of eutrophication Time of renewal of water Geological features such as the shape of the bottom of the water bodies Thermal stratification of stagnant water bodies (such as lakes and reservoirs) Temperature and light influence the development of aquatic algae

18. Potential negative impacts of eutrophication Trophic Status Ecological impact Economic impacts Human health impacts Recreational impacts Aesthetic impacts

19. negative impacts of eutrophication

20. Ecological impacts Macrophyte invasions impede or prevent the growth of other aquatic plants. Only the more tolerant animal species can survive due to algal bloom . Turbidity of water increases Release of cyanotoxins by cyanobacteria are recognized to have caused the deaths of wild animals, farm livestock, pets, fish and birds in many countries. Decreased oxygen levels can have a number of secondary water quality impacts.

21. Cyanotoxin and Human health impacts Cyanotoxins : Hepatotoxins (liver), Neurotoxins (neuron), Dermatotoxins (skin) Affects in cells, tissues and organs Nervous, digestive, respiratory and cutaneous systems Fatigue, headache, diarrhea, vomiting, sore throat, fever etc.

22. Management Monitoring prevention

23. Monitoring of eutrophication To prevent the occurrence of eutrophication Early warning purposes to the Public health authorities To know the level of development of the process, and have a precise picture of the quality of the water . Research and multipurpose .

24. parameters used for monitoring purposes Nitrogen and phosphorus Suspended solids Dissolved oxygen Bacteria Algal or cyanobacterial biomass Development of short living species of macrophytes

25. Prevention Identification of all nutrient sources Catchment area of the water supply Industrial activities, discharge practices and localization Best agricultural practices (fertilizer contribution/plant use and localization of crops) Nature of the soil, vegetation and the interaction between the soil and the water Knowledge of the hydrodynamics The way nutrients are transported, and of the vulnerability of the aquifer

26. Prevention cont. Fertilization balance for nitrogen and phosphorus Regular soil nutrients analysis Sufficient manure storage capacities Prevention of erosion of sloping soils Precise irrigation management and soil moisture control Reuse and recycling of water in aquaculture and agriculture.

27. Thank you