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 crew Many 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’