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OCEAN RESOURCES. Improvements. When was plastic first made? A graph on plastic consumption! How much gold in ocean? Currently, between 10 and 13 billion gallons of water are desalinated worldwide per day. That's only about 0.2 percent of global water consumption, but the number is increasing.
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Improvements When was plastic first made? A graph on plastic consumption! How much gold in ocean? Currently, between 10 and 13 billion gallons of water are desalinated worldwide per day. That's only about 0.2 percent of global water consumption, but the number is increasing.
Mandatory Practice Work 1/12/12 • You have some water…in 20 lbs of it there is 3.5 lbs of salt. What is the salinity? (both % and %0) • Rabbits has 2,200 lbs of water with a salinity of 7%. How many pounds of salt are in it? • Cory is in a boat and uses sonar. It takes 9.0 s for the sound to return. How deep is the water?
Bell Work 12/7/11 – 2 minutes • What is the most valuable ocean resource? • What is the most plentiful ocean resource?
Bell Work 12/8/11 – 4 minutes • What is the base of the ocean food chain? • How is salt obtained from ocean water? • What are 3 ways fresh water is obtained from ocean water?
Natural Resource • Something, such as a forest, mineral deposit, or fresh water, that is found in nature & is necessary or useful for humans
How much salt is in the ocean? • There is 50 quadrillion tons in the oceans. • If the salt in the ocean could be removed and spread evenly across all of Earth’s land it would form a layer more than 500 feet tall…the height of a 40 story building!
How do we harvest salt? • Harvested via evaporation
How is sea salt harvested? • http://www.youtube.com/watch?v=SQAdhQOcboE • Start at 4:50
Bell Work 12/13/13 Do 1-5 on the study guide
Missing Work 20.2 Quiz 1st - Dade 4th - Nevin 20.3 Reading Guide 1st - 4th - Sammy, Bri
How much should a half pound of sea salt cost? • Pump water into a field (about 2 gallons) • Wait a week for it to evaporate. • Rake into a pile, put in bucket & carry away • Dry out further elsewhere • Take out the impurities • Vacuum seal it in plastic • Plastic – drill hole, pump oil, transport, refine, make plastic • Drive it to a boat • Ship it across the ocean • Unload & drive it to a warehouse • Drive it to your house
Guy gets salt from a gallon of sea water • http://www.youtube.com/watch?v=JdnkG8wGNwM&feature=related
How is sea salt different from table salt? • Table salt is iodized • includes a small amount of potassium iodide or sodium iodide • People need small amount of iodine • necessary for the proper functioning of thyroid gland. • Prevents enlargement of the thyroid gland, a condition called goiter. • iodine deficiency during pregnancy dangerous to child
How is sea salt different from table salt? • SEA SALT • Mostly same chemical makeup • Slightly different taste, color, or texture. • contains natural traces of other minerals, including iron, magnesium, calcium, potassium, manganese, zinc and iodine. • “bright, pure, clean” flavor • It already contains iodine, so it doesn’t need to be iodized.
Water Water Everywhere and Not a Drop to Drink. • Drinking sea water is dangerous and can result kidney failure. • Dr. Bombard proved you can drink seawater! • No more than 32 oz/day • He drifted on a raft in the ocean for 63 days, surviving on “nothing more than the ocean provided”.
Fresh Water from the Ocean • Desalination • Extraction of fresh water from salt water • Harder than harvesting salt from ocean water • Advantages • There’s lots of ocean water! • water always available, even in droughts
Fresh Water from the Ocean • Disadvantages • Costly • Becoming more viable as technology improves & demand rises • Changes local salinity levels, which can harm local organisms • Plankton and tiny sea creatures in the water are removed for the process • Why is this important? • They can be vacuumed out & returned! $$
3 Methods of Desalination • Distillation – water heated to remove salt • Freezing - freeze ocean water, remove first ice that forms & thaw it • Reverse osmosis desalination - water is forced through special membranes under pressure, membranes block salt but allow water through
Distillation • water heated to remove salt • Salt stays behind when water evaporates • Requires a lot of energy, expensive • http://www.youtube.com/watch?v=CieNY9bxnYo&NR=1
Distillation • Oldest method…sailors have been using distillation to separate salt from sea water for at least several thousand years. • Wasn’t common on ships because it takes a lot of wood to distill water & fires are dangerous on wooden ships.
Freezinghttp://www.youtube.com/watch?v=6WpNs-aJBlc&NR=1 • first ice crystals do not contain salt • Freeze ocean water, remove first ice that forms, & thaw the ice • Advantage – cheaper!!
Northern Chile – dry atmosphere & cold nights make desalination via freezing cheap • Water evaporation rate = 5 mm/night • Also cools lots! • make it possible to freeze salt water, placed in pans which are oriented towards the open sky. • After controlled melting, the ice yields approximately 9 liters of fresh water per square meter of pan surface per day. • water costs are estimated at $0.10/m3. • Water is used in greenhouse crop cultivation in the desert
Reverse Osmosis • Reverse osmosis • seawater is forced through special membranes under pressure, membranes block salt but allow water through
Mineral and Energy Resources • Take out ze homework!
Petroleum • Most valuable resource in ocean • Oil and gas wells are drilled in the ultra-deep waters of the Gulf of Mexico and beyond. • drill on a ship, platform, or gigantic legs that rise the floor up. They begin drilling in the sea floor until they hit the oil. Then they must use a pump to remove the oil. • Workers make $50,000 - $100,000 /year depending on job
Nodules • Potato shaped lumps of minerals • manganese, iron, copper, nickel, cobalt, phosphates • Very deep in ocean and scattered, so recovery is expensive & difficult • Currently too expensive to be economically viable
Trace Minerals • Tiny amounts of minerals dissolved in ocean water • Magnesium & bromine – ocean is our main source for these minerals! • Other trace minerals too scarce to be worth it • Includes gold!
Other Resources • Oxygen! • About half of the world’s oxygen is produced by phytoplankton (algae). • Salt, Sand, Gravel • Food
Bell Work 5/8/12 – 4 min • How is salt harvested from the ocean? • What is the difference between sea salt and table salt? • Table salt is iodized to prevent what? • What does drinking too much salt water cause? • List the 3 methods of desalination.
Bell Work 5/9/12 – 4 min • Why are phytoplankton so important to life on Earth? • What is the disadvantage of distillation? • Explain reverse osmosis diffusion. (c.s.)
Learning Targets • Define bycatch • Explain the 6 main methods of ocean fishing & identify the environmental effects • Recite income of Alaskan Crab Fishermen • Identify most expensive seafood • Identify the reasons for, methods of, and legality of whale hunting.
People are eating more fish than ever! • What do we eat? • Tuna, Flounder, Anchovy, Cod • Lobster, Crab • Shrimp • Clams, Oysters, Scallops • Mullet • Herring • Squid
Food from the Ocean • Which fish are overfished? • Alaskan Pollock, Blue Fin Tuna, Sharks, Swordfish, Whales • Endangered blue fin tuna
Bycatch – unwanted marine animals caught when fishing for another species
How are fish harvested? • Trawling • Purse Seine • Pot & Trap • Long Line • Gill Net • Pole
Trawling • Trawl nets, which can be as large as a football field, are either dragged along the sea floor or midway between the floor and the surface. • Trawlers catch fish such as pollock, cod, flounder and shrimp. • Sea cucumbers & pearl oysters
Trawling • Bottom trawling results in super high levels of bycatch. • Bottom Trawling • Also rips up the bottom of the ocean, killing lots of benthos. • Destroy coral • Bottom trawling is the most destructive & irresponsible fishing method. • Illegal in all RMFOs, but hard to police. • Possible prevention - place huge rocks at strategic locations inside the oceans to discourage bottom trawling