Marine Pollution. Pollution in coastal waters. Coastal waters are highly affected by pollution because they are: Heavily used Close to sources of pollution Shallow-water bodies Not as well circulated as the open ocean. Marine pollution: A definition.
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Pollution in coastal waters • Coastal waters are highly affected by pollution because they are: • Heavily used • Close to sources of pollution • Shallow-water bodies • Not as well circulated as the open ocean
Marine pollution: A definition The introduction by man of substances or energy into the marine environment, which results in harm to marine life, hazards to human health, hindrance to marine activities, including fishing and other legitimate uses of the sea, impairment of quality for use of sea water and reduction of amenities. (WHO)
Main types of marine pollution • Sewage sludge • DDT and PCBs • Mercury • Nuclear Radiation • Non-point-source pollution • Petroleum (oil)
Marine pollution: Sewage sludge • Sewage sludge is the semisolid material that remains after sewage treatment • Much sewage sludge was dumped offshore until laws restricted sewage dumping
Marine pollution: DDT • DDT was a widely used pesticide that became concentrated in marine fish • DDT caused brown pelicans and ospreys to produce thin egg shells • Worldwide, DDT has been banned from agricultural use but is still used in limited quantities for public health purposes
Marine pollution: PCBs • PCBs are industrial chemicals used as liquid coolants and insulation in industrial equipment such as power transformers • PCBs enter the marine environment through leaks and from discarded equipment • PCBs can accumulate in animal tissues and affect reproduction
Mercury and Minamata disease • Mercury has many industrial uses but is extremely toxic • A chemical plant released large quantities of mercury into Minamata Bay, Japan • Residents who ate highly contaminated fish suffered neurological disease and birth disorders (Minamata disease)
Nuclear Radiation • Caused by leaking of containment structures • The severity of this contamination depends on the life of the radioactive isotopes that would be released if a meltdown were to occur. Some like iodine 131, would only affect humans if plants and vegetables were consumed immediately after contamination because they quickly degrade. Others, like caesium, are more dangerous because they remain radioactive for about 28 years.
Fukushima Daiichi nuclear disaster • Fukushima Daiichi nuclear power plant went into a meltdown after an earthquake and 49 foot tsunami destroyed the plant, cooling pumps, and generators on March 11, 2011 • Core reactor temperatures reached over 5000◦F. • The saga continues as workers try to contain the continually leaking reactors.
Non-point- source pollution • Non-point-source pollution comes from material washed down storm drains as “poison runoff” • Includes fertilizers, pesticides, road oil, and trash
Law regulating ocean dumping The only substance that is illegal to dump anywhere in the ocean is plastic
Plastic in the marine environment • Plastic: • Does not biodegrade • Floats • Has high strength • Is ingested by and entangles marine animals
Marine pollution: Petroleum • Oil spills can be caused by: • Tanker accidents • Intentional dumping • Drilling/pumping operations
Marine pollution: Petroleum • Petroleum is biodegradable • Many pollution experts consider oil to be among the least damaging ocean pollutants • Data from the 1989 Exxon Valdez oil spill shows the recovery of key organisms
Exxon Valdez • 1989 • Prince William Sound, Alaska • Hit a reef • Ship leaked 11 million gallons of oil from a tank • Some oil still left after 22 years
BP Deepwater Horizon Rig • April 20, 2010 • Drilling rig exploded • Gulf of Mexico (48 mi. from Mississippi River) • Over 6 million gallons so far • Huge reservoir of oil that is leaking (not as limited as ship leak) • Has entered Loop Current
Examples of damage… • 11 workers are presumed dead • 187 turtles stranded • 18 dead dolphins • Hundreds of bird nests Pelican covered in oil, Associated Press
Dangers to Wildlife • Damage to sea grasses that hold wetlands together • Over 70% of US water birds use Lousiana’s wetlands for rest or nesting • Danger for fisheries (oysters & trout are spawning this time of year) • Harm to Florida coral reefs
Ways to Clean Up Oil Spills • Booms • Skimmers • Sorbents • Dispersants • Burning • Bacterial breakdown • Kevin Costner’s centrifuge
Marine pollution: Petroleum • When oil washes up at a beach, it can negatively affect the marine environment • Oil can coat marine organisms and render their insulating fur or feathers useless Oil on the beach from the Exxon Valdez oil spill, Alaska