Marine pollution. Definition.
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Marine pollution Definition "Introduction of man, directly or indirectly, of substances or energy into the marine environment (including estuaries) resulting in such deleterious effects as harm to living resources, hazard to human health, hindrance to marine activities including fishing, impairment of quality for use of sea-water, and reduction of amenities.” – GESAMP
Contd.. Marine pollution General impacts • 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
Sources of pollution Land-based sources • Agricultural run-off • Municipal and industrial wastes Sea-based sources • Oceanic dumping • Offshore oil spills
Contd.. 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 POINT SOURCES Rural homes NONPOINT SOURCES Cropland Animal feedlot Urban streets Factory Suburban development Wastewater treatment plant
Types of pollution 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 Contd..
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
Contd.. Oil pollution Sources Source: UNEP
Contd.. Oil pollution Fate • When oil is spilled on sea it spreads over the surface to form a thin film – called oil slick • Light oil spreads faster than heavy wax oil • Low molecular weight fractions evaporate • Water soluble components dissolve • Non-water soluble components emulsify and forms a viscous mass – “chocolate mousse” • Heavy residues form tar balls
Contd.. Oil pollution Fate Tar balls Chocolate mousse
Contd.. Oil pollution Impacts • 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
Contd.. Oil pollution Impacts • Commercial damage • Mortality of fish, reduction in catch • Death of fish eggs and larvae • Tourism – becomes nuisance – avoided by beach goers – loss of revenue • Loss of sensitive marine habitats – loss of flora and fauna
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” - OSPAR (Oslo/Paris convention for the Protection of the Marine Environment of the North-East Atlantic)
Contd.. Eutrophication Sources • 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
Contd.. Eutrophication Impacts • Over-productivity • Reduction in phytoplankton species diversity • Growth of harmful algal blooms • Reduction in dissolved oxygen content • Anoxia and mass mortalities of marine organisms
Contd.. Eutrophication Global map of dead zones related to human-caused eutrophication (Scientific American, 2008)
Safwa STP Sanabis STP Eutrophication Awamiya STP & Nasira Agricultural Contd.. An example of Marine outfalls in Tarut Bay Jaruadiyah STP Anak North Agricultural Discharge Majidia Agricultural Discharge Anak South Agriculture discharge
Contd.. Eutrophication Total estimated discharges (m3/day)
Contd.. Eutrophication PME Receiving body Water Quality Standards
Contd.. Eutrophication Discharge Parameters (mean for 2006-2007) In excess of PME standards for direct discharge to receiving waters for a 30 day average.
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
Contd.. Conservative pollutants - Metals Natural Sources • Erosion of ore-bearing rocks • Atmospheric inputs - wind blown • dust • Volcanic activity • Forest fires • Riverine inputs into oceans
Contd.. Conservative pollutants - Metals Manmade Sources • Industrial discharge • Sewage • Re-suspension of sediments by dredging and trenching
Contd.. Conservative pollutants - Metals World-wide emissions (Clark, 2001)
Contd.. Conservative pollutants - Metals Impacts • 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.
Contd.. Conservative pollutants - Metals An example of Mercury pollution in MinamataBay, Japan (1953-1960) 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
Impacts of metal pollution by Bioaccumulation and Biomagnification
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
Bioaccumulation An example of bioaccumulation in Arabic Gulf
Biomagnification • Also called bioamplification • Increase in concentration of a substance in a food chain, not an organism
Conservative pollutants – Halogenated hydrocarbons • 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
Contd.. Conservative pollutants – Halogenated hydrocarbons Sources 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.
Contd.. Conservative pollutants – Halogenated hydrocarbons Impacts • 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
Thermal pollution Outfall from Qurrayah power plant, Saudi Arabia • Thermal pollution is the degradation of water quality by any process that changes ambient water temperature.
Contd.. Thermal pollution Sources • Industrial wastewater • Power plant discharges • Desalination plant discharges • Urban runoff
Contd.. Thermal pollution Impacts • Thermal shock • Decrease in dissolved oxygen • Increase in photosynthesis • Increase in metabolic rate of fish • Increase in oxygen consumption
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
Contd.. Radioactive pollution Sources • 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).
Contd.. Radioactive pollution Impacts • Highly lethal - Even low doses causes fatal damage • Possibility of bioaccumulation – especially in algae and bivalves • eg. Porphyranear a nuclear power plant location had 10 times more caesium-137 than in the surrounding waters
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 tidewrack.
Contd.. 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.
Contd.. 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.
Solution to pollution • Reduce input of toxic pollutants • Treat sewage primary, secondary and tertiary treatment • Ban dumping of wastes and raw sewage in nthe sea • Ban ocean dumping of sludge and hazardous dredged material • Protect sensitive areas from development, oil drilling, and oil shipping • Regulate coastal development