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Marine Pollution

• Marine pollution

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Marine pollution

• People use oceans as a sink for waste and pollutants• Even into the mid-20th century, coastal U.S. cities

dumped trash and untreated sewage along their shores• Nonpoint source pollution comes from all over

- Oil, plastic, chemicals, excess nutrients

In 2008, 391,000 Ocean Conservancy volunteers from 104 nations picked up 3.1 million kg (6.8 million lb) of

trash from 27,000 km (17,000 miles) of shoreline

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Nets and plastic debris endanger life

• Plastic items dumped into the sea harm or kill wildlife- Wildlife mistake it for food- 98% of dead northern

fulmars had plastic in their stomachs

• Plastic is nonbiodegradable- Drifts for decades- Breaks into tiny pieces

Trillions of tiny plastic pellets float in the oceans and are eaten

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Plastic trash is accumulating in the oceans

• Circulating currents bring and trap plastic trash to areas- The northern Pacific Gyre stretches from California to

Hawaii to Japan- This “Great Pacific Garbage Patch” is the size of

Texas and has 3.3 plastic bits/m2

• The 2006 Marine Debris Research, Prevention, and Reduction Act is not enough

• We must reduce, reuse, and recycle more plastic- Participate in efforts such as the International Coastal

Cleanup

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Oil pollution comes from spills of all sizes

• 30% of oil and 50% of natural gas come from seafloor deposits- North Sea, Gulf of Mexico

• Drilling in other places is banned- Spills could harm valuable

fisheries• The Deepwater Horizon

exploded off Louisiana’s coast in April 2010- Spilling 140 gallons/min- Hitting coasts of four states

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Oil spills have severe consequences

• Major spills make headlines- Foul beaches- Coat and kill animals- Devastate fisheries

• Countless non-point sources produce most oil pollution- Small boat leaks, runoff

Major oil spills cause severe environmental and economic problems

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Oil spills have decreased

• Due to emphasis on spill prevention and response- Stricter regulations are

resisted by the oil industry• The U.S. Oil Pollution Act

(1990)- Created a $1 billion

prevention and cleanup fund - Requires that all ships have

double hulls by 2015 Recently, oil spills have decreased

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Toxic pollutants contaminate seafood

• Toxic pollutants can make food unsafe to eat• Mercury contamination from coal combustion and other

sources bioaccumulates and biomagnifies- Dangerous to children and pregnant or nursing women

• Avoid eating swordfish, shark, and albacore tuna- Eat seafood low in mercury (catfish, salmon, canned

light tuna)• Avoid seafood from areas where health advisories have

been issued

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Excess nutrients cause algal blooms

• Harmful algal blooms = nutrients increase algae that produce powerful toxins

• Red tide = algae that produce red pigments that discolor water- Illness and death to wildlife

and humans- Economic loss to fishing

industries and beach tourism• Reduce runoff • Do not eat affected organisms

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III Marine Pollution

1. What is meant by the great pacific garbage patch?

2. Discuss three ways in which people are fighting pollution in the oceans and on our coasts.

3. We have been able to reduce the amount of oil we spill into oceans, but petroleum-based products such as plastics continue to litter our oceans and shorelines. Discuss some way we can reduce this impact on the marine environment.