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Ocean Pollution. Oil Spills. South Florida After heavy rain. Coastal Waters. 85% or more of ocean pollution comes from activities on land Pollutants such as oil, toxic wastes, and medical wastes Most pollutants affect coastal waters
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Ocean Pollution Oil Spills South Florida After heavy rain
Coastal Waters • 85% or more of ocean pollution comes from activities on land • Pollutants such as oil, toxic wastes, and medical wastes • Most pollutants affect coastal waters • Sensitive ecosystems like coral reefs, estuaries, and coastal marshes
Oil Spills • Yearly approx. 5-10 million gallons of oil from tanker accidents spill into oceans • Major sources • Cargo tanker washings: water drawn into ship to stabilize it when oil is discharged, then water is pumped back into ocean • Waste oil pumping: dumping by ships other than tankers • In-port oil losses: collisions, loading and unloading • Tanker accidents: most publicity • Exploration Losses: blowout of wells and accidental damage to offshore drilling rigs. • Motor oil: improper handling and disposal that eventually reaches coastal waters
Fate of Spilled Oil • Oil & water don’t mix…right? • When spilled, it spreads over the water quickly • Volatile components evaporate – 25% lost within days • The rest emulsifies (forms globs) of very thick & sticky material that eventually sinks • Any oil left is degraded (broken down) by microorganisms and photo-oxidation (light) • By the end of 3 months only 15% of original oil volume remains as a dense, black tarry lumps that wash up on shore
Effects Short Term Long Term • Blocking chemical messengers • Many marine animals use chemical messengers to find food, escaping predators, locating a habitat and for mating. • Oil that remains can block or mimic these • Human consumption • Toxic chemical build up in organisms harvested for human consumption • So we take in higher doses • Lower light transmission • Oil blocks light and photosynthetic organisms die • Lower oxygen levels • Organisms can suffocate • Damage to marine birds • Swimming or diving birds covered in oil can drown or become handicapped • Toxic effects • Poison many species of marine life
Countermeasures • Skimmers • Attached to ships skim a thin layer of water on surface, collected and separated on the ship then water is dumped back in ocean • Most affective in calm waters • Booms or barriers • Contain the oil slick then absorbed with materials like straw, powdered clay, sawdust, or chopped corn cobs stuffed in cloth tubes
Countermeasures • Chemical dispersants, detergents, and solvents • Chemicals used may also be toxic to the marine life • Burning • Oil doesn’t undergo complete combustion • Unburned (black smoke) contains toxic components now in the air • Unburned portion in water are potent carcinogens
Bioremediation • Mechanical cleanup methods can be expensive and have severe limitations • Wave action • Site accessibility • Weather • Equipment • Personnel • Natural processes to degrade (breakdown) oil take many years • Bioremediation process uses Oil-degrading microbes, like bacteria, yeasts and fungi, to break down oil into masses of food and other non-toxic components