Marine resources

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Lecture 8
Marine resources
23 August 2007
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Lecture schedule
Lecture Date Time 1. Introduction to
scientific writing 8/20 900-1020 2. How to
write a scientific paper in English 8/20 1500-16
20 3. Earth structure and plate
tectonics 8/21 900-1100 4. Circulation of the
atmosphere 8/21 1300-1500 5. Water and ocean
structure 8/22 1000-1100 6. Continental
margins and ocean basins 8/22 1300-1500 7.
Sediment 8/23 1000-1200 8. Marine
resources 8/23 1300-1400 9. Circulation of
the ocean 8/24 1100-1230
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6.6 billion (66 ??)
http//www.sustainablescale.org/images/uploaded/Po
pulation/World20Population20Growth20to202050.J
PG
Human population grew by 400 during the 20th
century
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Population growth
4.5 X increase in economic activity per person

• Each human now requires more goods and services
• so, the demand for Earths resources has grown
  faster than the population.

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Ten most populous countries 1. China 1.3
billion 19.8 2. India 1.2 billion 17.5 3.
USA 302 million 4.5 4. Indonesia 230
million 3.5 5. Brazil 187 million 2.8 6.
Pakistan 164 million 2.5 7. Bangladesh 159
million 2.4 8. Nigeria 159 million 2.2 9.
Russia 142 million 2.1 10. Japan 128 million
1.9 20. Thailand 63 million 0.9
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Number of people per square kilometer around the
world in 1994
of the worlds population living near the ocean
(1995) lt25 km 20 lt50 km 29 lt100 km 39
http//en.wikipedia.org/wiki/ImagePopulation_dens
ity.png
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Percentages of the total populations living lt100
km from the ocean Russia 15
China 24 Thailand 39 USA 43 Vietnam 83
Japan 96 Philippines 100 South Korea 100
(PICES, 2004 EarthTrends)
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• Four types of resources
• Physical (nonliving) resources
• result from the deposition, precipitation, or
  accumulation of useful substances in the ocean or
  seabed
• 2. Living resources
• animals and plants collected for human use
• 3. Marine energy resources
• 4. Nonextractive resources
• transportation and recreation

Renewable resources naturally
replaced Nonrenewable resources present in
fixed amounts and cannot be replenished over
short time spans - oil, gas
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• The most valuable physical resources from the
  ocean are
• Hydrocarbon deposits
• petroleum (crude oil)
• natural gas
• methane hydrate
• Mineral deposits
• sand and gravel
• magnesium and its compounds
• manganese nodules
• phosphorites
• Fresh water

In each case, terrestrial resources are easier to
obtain and less expensive to develop (until
depletion).
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The oceans most valuable resources are petroleum
and natural gas.

• Global demand for oil grows gt2 per year
• increased demand from China and India

Top petroleum-consuming countries 1. USA 2.
China 3. Japan 4. Russia 5. Germany
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http//archive.wn.com/2006/06/11/1400/thailandener
gy/
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• Much of the petroleum and natural gas comes from
  the ocean
• In 2000, 34 of petroleum and 28 of natural gas
  came from the seabed
• About 1/3 of known world reserves of oil and
  natural gas occur along the continental margins
• The deep-sea floor probably has little or no oil
  or natural gas

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• Petroleum is almost always associated with marine
  sediments
• suggests that it formed from marine material
• Most geologists think crude oil and natural gas
  came from compression and heating of ancient
  organic material

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According to this theory, oil is formed from the
preserved remains of zooplankton and algae that
settled on the sea bottom.
Land plants tend to form coal
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• If the material was heated too long or at too
  high a temperature, it turned into methane
• the main component of natural gas
• Deep sedimentary layers are older and hotter than
  shallow ones
• so they produce more natural gas
• few oil deposits below 3 km depth
• below 7 km, only natural gas

• Oil is less dense than the surrounding sediment
• so it can migrate toward the surface
• it collects in the pore spaces of reservoir rocks

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• Oil is less dense than the surrounding sediment
• so it can migrate toward the surface
• it collects in the pore spaces of reservoir rocks

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Drilling for oil offshore is much more expensive
than drilling on land. Most marine oil deposits
are tapped from offshore platforms in water lt100
m deep.
http//www.solarnavigator.net/images/oil_platform_
rig_hibernia.jpg
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http//www.artdiamondblog.com/images/OilInWaterMap
-thumb.gif
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• a number of significant recent oil discoveries
• Thailand's largest natural gas field (Bongkot)

http//en.wikipedia.org/wiki/ImageGulf_of_Thailan
d.svg
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• The largest known reservoir of hydrocarbons on
  Earth is not coal or oil
• it is methane hydrate
• also called methane clathrate
• a solid form of water that contains a large
  amount of methane within its crystal structure
• large deposits occur at 200-500 m below the
  seafloor

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Worldwide distribution of confirmed or inferred
offshore gas hydrate-bearing sediments.
Even extracting the methane form the sediment and
liquefying it for efficient use would be
prohibitively dangerous and expensive.
http//en.wikipedia.org/wiki/ImageGas_hydrates_19
96.jpg
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Marine sand and gravel are used in construction.

• In Japan, about 20 of sand and gravel used comes
  from the seafloor
• Largest mining operation is at Ocean Cay in the
  Bahamas
• aragonite sand - about 97 CaCO3

• used in cement, glass and animal feed

24

• Magnesium
• third most abundant element in seawater
• it usually precipitates as MgCl2 or MgSO4
• about half of magnesium metal production comes
  from seawater
• 1 producer is China
• used a strong, lightweight material in aircraft
  and structural applications

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Salts are harvested from salt evaporation ponds.

• The oceans salinity is about 3.5
• When seawater evaporates, the major ions combine
  to form salts
• calcium carbonate (CaCO3)
• gypsum (CaSO4)
• table salt (NaCl)
• Seawater is evaporated in salt ponds to recover
  the salts

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Products Used for Magnesium salts aircraft
and buildings Potassium salts chemicals,
fertilizers Bromine medicines Gypsum wallboar
d and other building material Sodium
chloride table salt, road salt
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Salt evaporation pond in San Francisco Bay
http//farm1.static.flickr.com/61/176838905_1d1980
1271.jpg
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Salt evaporation pond in San Francisco Bay
Red color due to algae and other microorganisms
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Salt farm near Samut Sakorn, Thailand
http//www.flickr.com/photos/dale_allyn/sets/27209
2/
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• Manganese nodules
• contain concentrations of valuable minerals
• iron, manganese, copper, nickel, cobalt

http//teachers.sduhsd.net/hherms/herms/ocean/sedi
mentation/nodules.gif
http//content.answers.com/main/content/img/McGraw
Hill/Encyclopedia/images/CE403150FG0010.gif
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http//geology.uprm.edu/Morelock/8_image/noddst.gi
f
No commercial mining yet.
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• Guano
• droppings of seabirds, bats and seals
• an effective fertilizer and gunpowder due to its
  high levels of phosphorus and nitrogen

Guano mining in the Central Chinchua Islands, ca.
1860
http//en.wikipedia.org/wiki/ImageDSCN5766-guano-
glantz_crop_b.jpg
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Nauru
http//www.washingtonpost.com/wp-srv/inatl/images/
searchtheworld/nauru_map.gif
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Phosphate field on Nauru
http//upload.wikimedia.org/wikipedia/commons/2/20
/Nauru-phosphatefields.jpg
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Phosphate field on Nauru
http//www.holon.se/folke/kurs/Nauru/nauru2.jpg
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Fresh water can be obtained from desalination.
Only 0.017 of Earth water is liquid, fresh, and
near the surface. One of the most important
factors for determining how many people can
inhabit an area is the availability of potable
water.
Fresh water is becoming an important marine
resource.
desalination

• Middle East
• West Africa
• Peru
• USA (Florida, Texas and California)

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• Desalination methods
• 1) Distillation by boiling
• expensive
• 2) Freezing
• 3) Reverse osmosis
• requires less energy, but filters are fragile and
  expensive

http//www.zenon.com/image/resources/glossary/reve
rse_osmosis/reverse_osmosis.jpg
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Desalination plant in Israel

• More than 1,500 desalination plants are currently
  operating worldwide
• produce a total of about 13.3 billion liters of
  fresh water per day

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Energy from heat or motion of seawater.
The energy crises of 1973 and 1979, and the rise
in the cost of crude oil in 2006 focused public
attention on alternative energies.
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Wind
The fastest-growing alternative to oil as an
energy source is wind power.
wind farm
http//msnbcmedia4.msn.com/j/msnbc/1137000/1137737
.widec.jpg
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Offshore wind farm in Denmark
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??????
???????
Hokkaido, Japan
http//homepage3.nifty.com/carib7/photo/h/muroran/
wind02.jpg
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Hokkaido, Japan
http//www.dbj.go.jp/japanese/environment/finance/
project/img/case02.jpg
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 Energy from waves and currents

• Pelamis Wave Energy Converter
• now being installed off Portugal
• soon to be installed off Scotland

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generator
motor
http//www.changingideas.com/Pelamis-Wave-Energy-C
onverter/wave-graphic.jpg
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Ocean currents
http//www.eia.doe.gov/kids/energyfacts/sources/re
newable/images/tidalturbine.gif
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Energy from the oceans vertical thermal gradient
The greatest potential for energy generation lies
in exploiting the thermal gradient between warm
surface water and cold deep water.
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Ocean Thermal Energy Conversion (OTEC)
http//staff.aist.go.jp/masa-amano/otec-m.gif
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OTEC plant in Hawaii
Problem efficiency of OTEC plants is only about
2
http//ja.wikipedia.org/wiki/E794BBE5838FOT
EC_in_Hawaii.jpg
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Living resources

• The oceans most valuable living resources are
• fish
• crustaceans
• mollusks

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Global marine landings by taxa (1950-2003)
90,000,000 tonnes/year
Catches are now declining despite increasingly
effort and better equipment.
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89 of landings come from EEZs
(Watson and Alder, 2003)
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• Fishing is big business
• employs gt 15 million people

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Todays fisheries are not sustainable.
About 90 of the worldwide stocks of tuna, cod
and other large fishes have disappeared in the
last 50 years.
Fishers are expending more effort, but are
catching fewer fish.
Overfishing
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Decline of fisheries in the North Atlantic
1900
1950
1999
1975
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Fishers sometimes abandon an exhausted fishery to
search for a new one
1980s
http//en.wikipedia.org/wiki/ImageOrange_roughy.p
ng
Boom and bust
Orange roughy
1990s
http//en.wikipedia.org/wiki/ImageToothfish.jpg
Patagonian toothfish
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Jellyfish!
http//www.ssken.co.jp/topics/rensaikiji/020724.jp
g
http//www.chugoku-np.co.jp/Nie/concourt03/kansou1
.html
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Marine food chain
?
??
http//www.seafriends.org.nz/issues/fishing/pauly1
1.gif
http//www.wappingersschools.org/RCK/staff/teacher
hp/johnson/visualvocab/FoodChain.jpg
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61
Fish catches in the Gulf of Thailand
Thai-German bilateral project introduced Engel
trawls for demersal fish
Pauly and Chuenpagdee, 2003
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Catch and relative abundance of demersal
resources vs. effort by Gulf of Thailand trawlers
Pauly and Chuenpagdee, 2003
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Pauly and Chuenpagdee, 2003
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The United Nations formulated the International
Law of the Sea
(22.2 km)
(370.4 km)
High seas
Nations hold sovereignty over resources, economic
activity, and environmental protection within
their exclusive economic zones.
exclusive economic zone
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The exclusive economic zone extends 200 nautical
miles from each countrys shore.

• about 40 of world ocean under control of
  coastal countries

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Tokdo/Takeshima
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Tokdo/Takeshima
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Senkaku/Diaoyu Islands

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http//en.wikipedia.org/wiki/ImageDiaoyutai_senka
ku.gif

• Senkaku Islands
• group of uninhabited islands now controlled by
  Japan
• also claimed by China and Taiwan
• total area 7 km2

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???(??????)
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???
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Key points 1. Nonliving resources are useful
substances from the ocean or seabed. 2. Energy
can be extracted from heat or motion of
seawater. 3. Living resources are being harvested
from the ocean for human use. 4. The law of the
sea governs marine resource allocation.
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Lecture schedule
Lecture Date Time 1. Introduction to
scientific writing 8/20 900-1020 2. How to
write a scientific paper in English 8/20 1500-16
20 3. Earth structure and plate
tectonics 8/21 900-1100 4. Circulation of the
atmosphere 8/21 1300-1500 5. Water and ocean
structure 8/22 1000-1100 6. Continental
margins and ocean basins 8/22 1300-1500 7.
Sediment 8/23 1000-1200 8. Marine
resources 8/23 1300-1400 9. Circulation of
the ocean 8/24 1100-1230