oceans. vitally important to our planet ocean conveyor (current) regulates world temperatures by...

Oceans

Vitally Important to Our Planet

• Ocean conveyor (current) regulates world temperatures by transporting heat from tropical regions to northern regions

• Starting point of the Hydrological Cycle (evaporation, water vapour, clouds, snow, ice)

• Carbon sinks and producers of oxygen (phytoplankton produce 25% of the world’s oxygen)

Ocean Pollution

• Shared dumping ground

• Shoreline areas, which teem with aquatic life are the most polluted areas of our oceans

• Rivers bring agricultural, city and industrial waste

• Tides bring pollutants back to shore

Types of Marine Pollution

• Oil : in transit for our use– Tanker accidents “Exxon Valdez”

• Biggest culprit “US” ; oil from drains, streets. The oily runoff from a city of 5m people can be equivalent to one oil tanker spill

• Bilges; past a problem but more regulation• Technology now ‘fingerprinting oil’• Satellite tracking• Recycling of used oil• Recreational boating• Off shor oil drilling• Illegal dumping by cruise ships

Can carry 2,600 people and 1200 crewMany now have sewage treatment on board

Agricultural run-off

• fertilizers, pesticides and herbicides used to increase crop yields

• Chemicals are not bio-degradable• Rainwater washes them into streams• Infiltration carries them through the soil and out,

often super-enrich these streams increasing plant growth until it becomes oxygen starved – eutrophication

• creating dead zones ; often near river mouths

Sewage

• waste from urban centers– Cost to treat waste– Primary treatment (just removing solids)

• Many urban centers barge waste out to sea and dump it

• Worst Canadian centers, Victoria, Saint John, Halifax, St. John’s

• Storm and sanitary sewers (combines snow this has stopped in many centers)

• Industrial waste and thermal pollution• Chemicals and heavy metals

Why Should We Be Concerned?

• Oceans like Tropical Rainforests …oxygen, carbon dioxide and the hydrologic cycle

• We might need to become ‘farmers of the seas’