Ocean Pollution

Ocean Pollution

Think about it….• How could ocean pollution

affect your life?

• Think of ways you contribute to ocean pollution in your daily life.

• Petroleum hydrocarbons• Plastics• Pesticides• Heavy metals• Sewage• Radioactive waste• Thermal effluents

Marine PollutantsMarine Pollutants

Where does ocean pollution come from?

• 85% comes from activities on land– Pollution from rivers– Pollution from coasts

•Estuaries and coral reefs• Direct dumping

– Wastewater– Oil spills

Review

• Non-Point Source Pollution – – comes from many sources

• Point-Source Pollution – – one specific source

Non-Point source pollution

• Most ocean pollution is non-point source

• Human activities on land pollute streams and rivers which flow to oceans

• Stormwater runoff and agricultural runoff are the most common sources. They increase nutrients too much and cause algal blooms. Dissolved oxygen levels drop and cause fish to die = EUTRIFICATION!

• Difficult to control and clean

Trash Patches (Don’t write)• North Pacific Gyre – World’s worst example of pollution• Twice the size of Texas • Floating soup of plastic bags • and other goods which has • collected over many years • because the clockwise, circular • current and lack of wind drives • floating debris into the center • of the gyre.

So what? (Don’t write)

• A turtle found dead in Hawaii had over a thousand pieces of plastic in its stomach and intestines.

• It has is estimated that over a million sea-birds and one hundred thousand marine mammals and sea turtles are killed each year by ingestion of plastics or entanglement.

• Animals can become entangled in discarded netting and line.

There is more than one gyre…

Point-source pollution

• Clean-up is still difficult but it’s easier than cleaning up non-point source pollution– Trash dumping– Sludge dumping– Oil spills

Trash Dumping (Don’t Write)

• 1980’s scientists became alarmed at the kinds of trash in our oceans (bandages, vials of blood – contained AIDS, syringes)

• Found that hospitals dumped 3 million tons of medical waste/year = 6,000,000,000 pounds of trash

• Stricter laws created and now it is buried in landfills

• Some trash dumping still occurring in deep ocean by some countries

• EFFECTS: trash (especially plastic) harmful to animals b/c they mistake it for food

Sludge Dumping (Don’t write)

• Sludge from raw sewage dumped into oceans

• Dumped offshore with hopes of it sinking to bottom, BUT due to currents, often it is moved closer to shore where it pollutes beaches and kills animals/plants

• Banned in most places but some countries still dump

Oil Spills (Don’t write)

• Oil is in high demand all over the world• Transported in huge tankers across oceans• Oil spills occur when oil is not handled properly

• EFFECTS: – Countless animals and plants die.– Even after clean up, environment will suffer for

decades

Only 5% of oil pollution is from oil spills

Most of oil that pollutes oceans is non-point source from cities and towns

BUT…

Saving our Ocean Resources (Don’t Write)• Citizens of countries have acted by petitioning their

government for stricter laws and starting events like “beach clean-ups”

• United States – 1972 – “Clean Water Act” put EPA in charge of issuing permits for ocean dumping

• United States – 1972 – “US Marine Protection, Research and Sanctuaries Act” – prohibit dumping of any material that would affect human health or welfare, the marine environment or ecosystems, or businesses that depend on the ocean.

• 1989 – Several nations joined together to pass a treaty that prohibits dumping of certain metals, plastics, oil and radioactive waste

• Dumping and oil spills still occur• Enforcing laws is difficult b/c oceans take up 71 % of the

Earth, hard to monitor

Preventing Ocean Pollution

• 1974 Helsinki Convention – international laws prohibit dumping toxins like DDT, cadmium and mercury

• United States:– Marine Protection, Research and

Sanctuaries Act– Oil Pollution Act– Marine Mammal Protection Act

Who Owns the Oceans?

• Each country is in charge of environmental preservation and clean-up up to 200 nautical miles (230 miles) from coast

• “Open seas” controlled by International Seabed Authority– Signed by 134 nations but not the

U.S.