Oceanography Chp 11

• Unprecedented Assault


  • Increased Population
  • Improved Economies
  • Increase in consumption rates
  • Advancement in technology
• Marine Resources


  • Physical
  • Biological
  • Non-extractive
• Physical marine resources


  Mineral deposits, freshwater for use
• Biological marine resources


  Living animals and plants
• Non-extractive marine resources


  Uses of ocean in place
• Petroleum & Natural Gas formation

  1. Planktonic organisms will form into petroleum

  2. Need low oxygen, high pressure and great depths
• Physical marine resources


  • Petroleum
  • Sands & Gravel
  • Salts
  • Freshwater
• 1% of world's total sand and gravel production dredged from continental shelves per year
• Aragonite Sands from Ocean Cay, Bahamas
• Evaporation of seawater leaves calcium carbonate, calcium sulfate and sodium chloride and mixture of magnesium and potassium salts
• 1/3 of salt produced from seawater
• Desalination


  Separation of pure water from seawater
• Methods to obtain freshwater from seawater

  • Distillation
  • Freezing
  • Reverse osmosis
• Top 10 fishing nations worldwide in 2018 (in million metric tons)
• Cost of Fish


  Increased due to cost of fuel, cost of wages, further distances needed to travel to get to fish
• Maximum Sustainable Yield


  Maximum amount that can be caught without jeopardizing future stocks
• Fish Mismanagement


  • Can lead to by kill
  • Nearly ¼ of all landings
  • Disruptive fishing techniques like drift nets, long line fishing, bottom trawling

  
• Growth of World's Live Capture
• Only 1 million large whales left today
• 8 of 11 species of large whales commercially extinct

  
• Aquaculture


  In confined area
• Mariculture


  Usually in near shore environments
• Ranching


  Occurs in open ocean
• Uses of Algin (muscus from seaweeds)


  • Stiffening of fabrics
  • Emulsions
  • Salad dressings
  • Paint and printer's ink
  • Prevention of large crystals in ice cream
  • Clarify beers and wine
• 10% of marine organisms likely to yield clinical products
• Drugs from marine organisms

  • Acyclovir (from a sponge) fights herpes
  • Vidabrine (from cyanobacteria) may attack Aids virus
• Oil pollution


  • Most components don't dissolve easily in water
  • Kill many marine organisms
  • Consumptive uses of oil is largest source of oil pollution
• Rachel Carson: Silent Spring was first to recognize misuse of pesticides and first to identify bioaccumulation in food chain of toxins & heavy metals
• Biological Amplification


  Eutrophication alters physical, chemical and biological balances in ecosystem, stimulates growth in some species, causes oxygen depletion
• Plastic makes up approx 7% of solid waste stream
• Plastic kills 100,000 marine mammals and 2 million seabirds each year
• There are 18,000 pieces of plastic per square kilometer
• Biodegradation times for common products

  • Banana peel, 2 – 10 days
  • Cotton rags, 1 – 5 months
  • Sugarcane Pulp Products, 30 - 60 days
  • Paper, 2 – 5 months
  • Rope, 3 – 14 months
  • Orange peels, 6 months
  • Wool socks, 1 – 5 years
  • Cigarette filters, 1 – 12 years
  • Tetrapaks (plastic composite milk cartons), 5 years
  • Plastic bags, 10 – 20 years
  • Leather shoes, 25 – 40 years
  • Nylon fabric, 30 – 40 years
  • Plastic six-pack holder rings, 450 years
  • Diapers and sanitary napkins 500 – 800 years
  • Tin cans 50 - 100 years
  • Aluminum cans 80 - 100 years
  • Plastic Bottles, Forever
  • Styrofoam cup, Forever
• Sewage


  98% is water, sludge is remaining semisolid mixture of organic matter containing bacteria & viruses, toxic metals, synthetic organic chemicals & debris
• Ozone Depletion: In the stratosphere, UV radiation breaks down CFC molecules, releasing atomic chlorine. A free Chlorine atom reacts with an ozone molecule, converting it from O3 to O2.
• Greenhouse effect


  Natural, but accelerated rate of warming due to anthropogenic sources
• Consequences of Atmospheric Warming

  • Increase moisture content of certain air masses
  • Increase in violent weather in some regions
  • Increase magnitude and frequency of hurricanes
  • Change circulation patterns of wind and ocean currents
  • Expansion of ocean
  • Increase sea level
• Biological Changes from Climate Change

  • Biodiversity will be threatened
  • Major habitat changes
  • Reduce the range of many species
  • Increase of infectious diseases
  • Intertidal and wetland communities won't be able to adjust
  • Organisms will be affected by storm damage, wave erosion and sediment deposition
  • Ocean acidification reduces integrity of organisms
• Actions to address climate change

  • Alternative energy sources
  • Cleaner industry
  • Reduce energy usage
  • Make better decisions
  • Buying electronic vehicles
  • Buy less packaging
  • Energy efficient lightbulbs
  • Recycle
  • Buy local