Marine pollution

Marine pollution

1. Marine pollution Marine pollution  or  Ocean pollution  which is caused due to waste being dumped into such water bodies affects the biological processes of the  marine  ecology . Eighty percent of  marine pollution  comes from land.

2. Sources of pollution Land-based sources Agricultural run-off Municipal and industrial wastes Sea-based sources Oceanic dumping Offshore oil spills

3. Point and Non-Point Sources Point source – refers to a single identifiable source of pollutants eg . effluent outfall Non-point source – refers to diffuse source of pollutants eg. Acid rain, dust storms NONPOINT SOURCES POINT SOURCES Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot

4. Operational discharge from tankers during tank cleaning Bilge discharge from all vessels Spills due to marine accidents i.e., collision, grounding, explosion Spills during loading Deliberate discharge of sewage, garbage etc. Marine pollution from vessels can be divided into five categories:-

5. Discrete vs . Chronic Pollution Discrete (short term) – eg. an oil spill, the effects of which diminish with time Chronic (long term) – eg. nutrient input, effluent discharge Types of pollution

6. Types of pollution

7. Oil pollution Sources Source: UNEP

8. Impacts on living resources Hazards to human health Hindrance to marine activities Impairment of quality of seawater Reduction of amenities Loss of aesthetic beauty Impacts on the sensitive habitats General impacts Marine pollution

9. Oil pollution Oil pollution is mostly used to describe marine oil spills, where oil is released into the ocean or coastal waters. Oil spills are due to the following: crude oil from tankers offshore platforms drilling rigs and wells spills of refined petroleum products (such as gasoline, diesel) spill of any oily refuse or waste oil Oil Pollution:-

10. Other sources of oil pollution Ballasting / deballasting operation of tankers Discharge of oily bilge water Tank washing Refinery effluents Discarded lubricants and minor sources Accidents to tankers and other vessels Offshore exploration and exploitation Accidents to pipelines and terminals Natural seepages

11. Chocolate mousse Tar balls Oil pollution

12. Effects – Impairment of marine life Plankton, esp. neuston at highest risk – exposed to water soluble components leaching from oil Fixed vegetation –Sea grass beds– killed or flowering inhibited In Mangroves – lenticels clogged with oil oxygen level in sediments drops – death Sea birds –buoyancy and thermal insulation lost Oil pollution Impacts

13. Eutrophication “The enrichment of water by nutrients, especially nitrogen and/or phosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of water concerned”

14. Eutrophication Wastewater effluent (municipal and industrial) Runoff and leachate from waste disposal systems Runoff from agriculture/irrigation Runoff from pasture and range Runoff from mines, oil fields, unsewered industrial sites Overflows of combined storm and sanitary sewers Untreated sewage Sources

15. Over-productivity Reduction in phytoplankton species diversity Growth of harmful algal blooms Reduction in dissolved oxygen content Anoxia and mass mortalities of marine organisms Impacts Eutrophication

16. Conservative pollutants tend to be stable, long-lived compounds that persist within the environment. Non-conservative pollutants can transform or degrade into other compounds, but the rate of transformation depends on the physical, chemical, and biological conditions occurring within the receiving water environment. Conservative pollutants

17. Conservative pollutants - Metals A heavy metal is a member of a loosely-defined subset of elements that exhibit metallic properties. It mainly includes the transition metals, some metalloids, lanthanides, and actinides. There is an alternative term for heavy metal and is called as toxic metal The major sources of metals are: Natural sources Manmade sources

18. Erosion of ore-bearing rocks Atmospheric inputs - wind blown dust Volcanic activity Forest fires Riverine inputs into oceans Conservative pollutants - Metals Natural Sources

19. Industrial discharge Sewage Re-suspension of sediments by dredging and trenching Conservative pollutants - Metals Manmade Sources

20. Metal Natural sources (in thousand tonnes/year) Anthropogenic sources (in thousand tonnes/year) Arsenic 12 18 Cadmium 1.3 7.6 Copper 28 35 Lead 12 332 Nickel 30 56 Zinc 45 132 World-wide emissions (Clark, 2001) Conservative pollutants - Metals

21. Arsenic (As) Phytoplankton most sensitive & accumulate from water column Higher trophic levels accumulate via food. Cadmium (Cd) Divalent cadmium is more toxic Tends to bioaccumulate Lead (Pb ) Forms strong complex with clay and suspended material Bioaccumulates in most marine organisms – no significant problems. Conservative pollutants - Metals Impacts

22. Source Pollution from plastic plant- dumped mercuric chloride into the bay Impact Shellfishes contaminated with mercury People who consumed shellfish severely affected 43 dead and 700 permanently disabled Bay is still unusable for fishing and shell fishing Conservative pollutants - Metals

23. Bioaccumulation Increase in concentration of a substance(s) in an organism or a part of that organism The affected organism has a higher concentration of the substance than the concentration in the organism’s surrounding environment Not excreted or metabolised and failure of the target organ

24. Also called bioamplification Increase in concentration of a substance in a food chain, not an organis m Biomagnification

25. Hydrocarbons containing chlorine, fluorine, bromine or iodine . Differs from petroleum hydrocarbons – not degraded by chemical oxidation or by bacteria Low molecular weight compounds – eg., Dichloroethane , Freons etc. High molecular weight compounds – eg., DDT, Drins , PCBs Conservative pollutants – Halogenated hydrocarbons

26. Aerial transport Aerial spraying of pesticides as aerosols – travel great distances Freshwater inputs Rain washing of pesticides carried into sea by rivers Silt from flood Direct inputs By industrial outfalls – especially by Pesticide manufacturing companies. Sources Conservative pollutants – Halogenated hydrocarbons

27. Low solubility in water persist for long durations Fat-soluble , so incorporated into the tissue of marine organisms and sediments Lethal to the animal Possibility of transmission through food webs – established in a number of animals Impacts Conservative pollutants – Halogenated hydrocarbons

28. Thermal pollution Thermal pollution is the degradation of water quality by any process that changes ambient water temperature. Outfall from Qurrayah power plant, Saudi Arabia

29. Thermal pollution Sources Industrial wastewater Power plant discharges Desalination plant discharges Urban runoff

30. Thermal shock Decrease in dissolved oxygen Increase in photosynthesis Increase in metabolic rate of fish Increase in oxygen con sumption Thermal pollution Impacts

31. Radioactive pollution Radioactive wastes are usually by-products of nuclear power generation and other applications of research and medicine. Radioactive waste is hazardous to human health Pollution due to radioactive wastes – Radioactive pollution

32. Weapons testing – Testing of nuclear weapons – when exploded underwater release fission products and isotopes Liquid wastes – Discharge from the cooling water of nuclear reactors Solid wastes – Dumping of radioactive wastes in Sea (now no longer practiced). Radioactive pollution Sources

33. Highly lethal - Even low doses causes fatal damage Possibility of bioaccumulation – especially in algae and bivalves eg . Porphyra near a nuclear power plant location had 10 times more caesium-137 than in the surrounding waters Radioactive pollution Impacts

34. Litter and Plastics pollution Marine litter , is human created waste that has deliberately or accidentally become afloat in a the sea or ocean . It tends to accumulate at the centre of gyres and on coastlines, frequently washing aground, when it is known as beach litter or tide wrack .

35. Litter and Plastics pollution Sources Up to 80% of the pollution is land-based. A wide variety of anthropogenic artifacts can become marine debris Plastic Bags, Balloons, Buoys etc.

36. Litter and Plastics pollution Impacts Many animals that live on or in the sea consume flotsam by mistake, as it often looks similar to their natural prey Blocks the passage of food and causing death through starvation or infection. Tiny floating particles also resemble zooplankton, which can lead filter feeders to consume them and cause them to enter the ocean food chain. In samples taken from the North Pacific Gyre in 1999 by the Algalita Marine Research Foundation, the mass of plastic exceeded that of zooplankton by a factor of six.

37. Solution to pollution Reduce input of toxic pollutants Treat sewage primary, secondary and tertiary treatment Ban dumping of wastes and raw sewage in the sea Ban ocean dumping of sludge and hazardous dredged material Protect sensitive areas from development, oil drilling, and oil shipping Regulate coastal development