Transcript Life on an Ocean Planet - Home

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►Resource Classification
►Nonrenewable Resources
►Renewable Resources
►Biological Resources – Marine Mammals
►Biological Resources – Algae, Aquaculture and Medicine
Chapter Topic Menu
►Biological Resources – Fish
►The State of the World’s Fisheries – A Bleak Picture
►Commercial Fishing
►Who Owns the Sea?
►Biodiversity and the Future
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Resource Classification
 All resources have political and environmental significance because they all
have economic value.
 Two common categories for classifying marine resources are:
 Renewable and…
 Renewable resources are those that growing organisms, sunlight, or other processes
naturally replace.
 …Nonrenewable Resources
 Physical and…
Chapter 15 Pages 15-3 & 15-4
Resource Classification
 Nonrenewable resources are those that natural processes don’t replace, or that do so at such a
slow rate that they are not replenished in a human lifespan.
 Physical resources don’t involve biological processes. They include minerals, energy
production, and recreation.
 …Biological Resources
 Biological resources involve bioproductivity, such as fisheries and kelp harvesting.
 Most marine biological resources are potentially renewable, but some are not. It
happens when a fishery takes a species from the ocean faster than it can
reproduce and maintain its population. Whaling is an example of this.
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Energy
 Among the physical marine resources, petroleum and natural gas are the most
important to economic contribution. About one third of the world’s crude oil and
about a quarter of the natural gas comes from the sea.
 Petroleum and natural gas form from the remains of primarily marine organisms,
such as plankton and soft-bodied benthic organisms.
Chapter 15 Pages 15-5 to 8
Nonrenewable Resources
 Seismic instruments are used to help find oil and natural gas.
 Physical characteristics of the rock surrounding oil
and natural gas are important. This determines
where the oil or gas collects.
 Source rock is where hydrocarbons originate,
and collect in the spaces underneath reserve rock.
This is called an oil or gas reserve.
 Sound waves detect the oil and natural gas
reserves as low-density pockets in the reserve rock.
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Energy (continued)
 Oil companies use platforms to drill from to extract oil and gas by drilling
through sediment and rock into the reserves.
 Special drilling equipment is used to minimize the risk
of an oil spill or gas leak.
 The unusual hydrocarbon deposits consist of frozen
water molecules that create a “cage” within sediment.
Each “cage” holds a single methane gas molecule.
 They are another form of non-renewable hydrocarbon.
Chapter 15 Pages 15-8 & 15-9
Nonrenewable Resources
 Methane hydrates are ice crystals containing
methane found on the continental slope.
 They are not currently used as an energy
source because it is very expensive to
recover them and they are relatively
dangerous to handle.
 Technologies for handling methane
hydrates are in development.
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Salts and Minerals
 Ferromanganese Nodules - Nodules are rich in copper, nickel and cobalt as
well as iron and manganese.
 This makes ferromanganese nodules tremendously valuable.
Unfortunately, the cost of recovery at present exceeds
the worth of the minerals.
 Magnesium Compounds - About half the worldwide
magnesium production comes from seawater.
Chapter 15 Pages 15-10 to 15-13
Nonrenewable Resources
 Magnesium is the third most abundant element dissolved
in seawater. It occurs as magnesium chloride and
magnesium sulfate.
 Salts - Evaporites are the salts left behind when
seawater evaporates.
 Manufacturers use evaporites in the production of
fertilizers, medicines, wallboard, other building
materials, and table salt. Table salt in turn is used
for snow and ice removal, water softeners, agriculture
and food processing.
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Salts and Minerals (continued)

Phosphorite - Phosphorite or phosphate rock deposits are the
remains of marine organisms that live in areas with
extensive upwelling. Offshore phosphorite deposits are
currently uneconomical to exploit.

Marine Muds and Metals - Hydrothermal vent seawater carries
large quantities of dissolved metals and minerals including
zinc, iron, copper, lead, silver, cadmium and sulfur.

Chapter 15 Pages 15-10 to 15-13
Nonrenewable Resources

Today terrestrial sources are mined. It is estimated these deposits
may be depleted by the mid 21st century. To avert a crisis in
agriculture/industry, offshore deposits may be important.

In the Red Sea are hot brines producing muds rich in metal
sulfides, silicate, and other oxides in a high enough concentration to
make recovering them economically feasible.
Seamounts are potential resources, in particular cobalt deposits.
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Gravel and Sand
Chapter 15 Page 15-13
Nonrenewable Resources
 Sand and gravel are important marine resources. They are second to gas and
oil in terms of their annual economic value.
 Each year industry mines more than one billion metric tons of sand and gravel
from offshore deposits.
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Energy
 The sea provides several types of renewable energy for human use:
 1. Wave action accounts for two methods:
Chapter 15 Pages 15-15 & 15-16
Renewable Resources
 1. Building a caisson with an opening under water that
permits waves to enter and compress air in the chamber
forcing it through a turbine to generate electricity.
 2. Placing a series of buoys that rise and fall in the waves
cranking a wheel in a circle. An axle coming off the
wheel turns a generator.
 2. Tides can be be used for energy where tidal change
is 3 meters(10 feet) or more. As the tide flows in and out of
two way dams, its energy is used to turn turbine
generators. One in France produces 500
kilowatts yearly.
 3. Warm surface water is used by Ocean
Thermal Energy Conversion (OTEC) to vaporize
liquid ammonia which in turn drives a turbine.
Water is piped back to the deep sea.
 Of the three, the most feasible appears to be harnessing wave energy.
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Fresh Water
 The single most important factor determining how many people can live in a
given area is the availability of fresh water. Human population is rising, and
the demand for fresh water with it. The supply isn’t keeping pace, making this
resource a growing concern as we move through this century.
 Desalinization – getting fresh from seawater – involves removing dissolved
salts. Currently there are more than 7,500 desalinization plants worldwide, 60%
of which are in the Middle East. The Western Hemisphere accounts for only
12% of the fresh water produced by desalinization.
Chapter 15 Pages 15-17 & 15-18
Renewable Resources
 Recovery methods include:
 Boiling seawater - capturing and condensing water vapor.
 Freezing seawater - salt is left behind and fresh water is produced.
 Reverse osmosis - forcing seawater through a semipermeable membrane under pressure
letting the water through, but holding back the salt.
 Covering large shallow pools of seawater with plastic and recovering the condensation that
forms underneath the covers.
 One bottled water company even melts icebergs on special barges to get fresh water.
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Nonextractive Resources
 You may not think of these as resources, but they are. Nonextractive
resources are those we obtain from the sea without removing anything
from the sea. The two most conspicuous of these are sea transport shipping
and recreation.
Chapter 15 Pages 15-18 to 15-20
Renewable Resources
 After WW II, the invention of the cargo container
revolutionized sea transport shipping. Standardized cargo
containers made it possible to quickly load and unload ships.
Modern ships can hold more than 4,000 containers.
 Ecotourism focuses on visiting and experiencing natural
environments and wildlife. Much of it is on or near the sea.
 On the positive side, in a growing number of destinations local
people are realizing that they need to preserve the local environments.
 On the negative side, some areas have trouble keeping pace
ith the rising number of tourists. Construction and traffic are putting strain on the areas’ ecology.
Something seemingly as harmless as feeding fish can change wildlife behaviors.
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Whales
 With the crude methods of harpoon and longshore
boats, comparatively few whales could be taken and
whale populations remained stable.
 Everything changed in 1868 with the invention of the
modern harpoon gun.
 Whale populations have declined drastically during
the 20th century.
Chapter 15 Pages 15-21 & 15-22
Biological Resources – Marine Mammals
 Until 1868, primitive technology made whaling dangerous and difficult.
 International whaling has been so successful that from
an estimated whale population of 4.4 million in 1900,
today the estimated population is around 1 million.
 In 1982, the International Whaling Commission (IWC)
called for an indefinite moratorium on commercial
whaling that became effective in 1986.
 The gray, blue and humpback whales seem to be on the rise in the Pacific.
 Unfortunately, the right and southern blue whales in the North Atlantic appear to
still be declining.
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Whales (continued)
 IWC is a voluntary organization and even members don’t have to abide by its rulings.
 Whaling continues with the IWC’s allowance for aboriginal hunting to preserve their
cultural traditions. Often the “traditions” are carried out with modern equipment.
 Another exemption is for scientific whaling. Allowing whales to be taken as specimens
for study. Japan, in particular, continues to hunt whales using this clause with their
government authorizing 400 whale kills annually. These “specimens” are sold to
wholesalers and used as food in school lunches.
Chapter 15 Pages 15-22 to 15-24
Biological Resources – Marine Mammals
 Whaling continues despite the moratorium for several reasons:
Other Cetaceans
 Several small cetaceans are not protected under the moratorium:
 Dolphins have become the most endangered of the cetacean. They and small whales
are a by-catch problem in tuna fishing.
 Many countries eat dolphin. “Dolphin” on a menu in the US is a mahi-mahi fish.
“Dolphin” in Peru is dolphin.
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Seals and Sea Lions
Chapter 15 Pages 15-24 & 15-25
Biological Resources – Marine Mammals
 Historically, seals and sea lions have been biological resources exploited for
their fur and for food.
 Although the marine mammal
fur trade no longer exists in the
US due to the Marine Mammal
Protection Act and consumer
pressure, worldwide up to half a
million of these seals and sea
lions die for their fur annually.
 World opposition continues to
pressure Canada to ban the
harp seal hunt for the pups’ fur.
The killing of harp seal pups
continues. So public opposition will
continue, if for no other reason than
that many consider it offensive to
exploit these harmless and appealing pups.
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 Marine algae is another resource used as food.
 Annually, the Japanese consume nearly
150,000 tons of red algae nori.
 The commercial product algin, which comes
from the mucus in kelp and other marine
algae, is useful in food processing and
other applications.
 Algin is used as a food source in salad dressing, ice cream and is used to clarify
beer and wine. It is also used in paint and abrasives.
 The industry uses nearly $250 million worth of algin annually.
Chapter 15 Pages 15-26 & 15-27
Biological Resources – Algae, Aquaculture and Medicine
Algae
Farming the Sea
 The growth trend in aquaculture is steeply upward. Currently
it is growing three times faster than livestock production on
land and may exceed it in the next decade.
 Today about 25%-30% of the world’s seafood comes from aquaculture.
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 There are problems with farming the sea:
 Aquaculture also has problems similar to raising livestock on land.
Some farmed fish species take fish to feed them – salmon for example.
Keeping many animals in close quarters tends to allow disease to spread rapidly.
Drugs given to farmed fish to prevent disease pass through them into the environment.
Many pens release concentrated waste in the form of nitrates, leading to plankton blooms.
Aquatic farms consume resources that wild organisms would use.
Raising species not indigenous to the area raises a risk of throwing the local ecological balance
off should some escape.
 It can also compromise the gene pool of wild species if the domestic animals breed with them.
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Chapter 15 Pages 15-27 & 15-29
Biological Resources – Algae, Aquaculture and Medicine
Farming the Sea (continued)
New Medicines from the Oceans
 Bioprospecting is the search for organisms with pharmacological or other
chemical benefits.
 Bioprospecting is important in the development of new drugs because it is in
nature that chemists often find new ways to fight disease.
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Chapter 15 Pages 15-30 & 15-31
Biological Resources – Fish
Fisheries for Food and Industry
 About 18% of the protein we eat
in the US comes from the ocean.
Worldwide, it accounts for only
about 4% and varies by nation
and culture.
 Commercially important fish are
found primarily in two places:
the water of the continental
shelves and a few offshore
regions with abundant upwelling.
 Continental shelves and upwellings have high productivity because of the ample
supply of nutrients and sunlight.
 Clupeids – herring, sardines and anchovies account for the largest single
group that is taken for commercial harvest.
 Industrial fishing is catching for purposes other than direct human
consumption. Over one third of the commercial fish catch is industrial.
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Chapter 15 Pages 15-31 to 15-33
Biological Resources – Fish
Trends in the Worldwide Commercial Fish Catch
 Since WW II, the worldwide annual
catch has been greatly increasing.
 The commercial extinction of many
target fish, e.g. orange roughy, and the
decline of others including cod fisheries,
raises doubts in the minds of scientists
about the accuracy of the FAO’s
estimates and reports.
 Predicted trend is that soon the
worldwide fisheries will not be able to
meet the rising demand. Even the FAO
estimates that by 2010, the worldwide
catch will fall short of the demand.
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 The concept of maximum sustainable yield lies at the heart of fisheries
management.
 It is the number of a target species that fisheries
can take without jeopardizing future populations.
 The precise definition of overfishing is taking
more of a species than the maximum
sustainable yield.
 Evidence indicates overfishing in virtually all the
world’s fisheries.
Chapter 15 Pages 15-35 & 15-36
The State of the World’s Fisheries – A Bleak Picture
Maximum Sustainable Yield and Overfishing
 Fleets catch less than in past years, yet have to range farther for fish.
 Indications are that half the marine fisheries are overfished or already
commercially extinct.
 The FAO estimates that 70% of the worldwide fish stocks are overfished or depleted.
 The National Marine Fisheries Service estimates that 50% of the fish stock in US
waters is over fished.
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The Problems with Overfishing
 By refining technology and methods, they are taking ever larger proportions of
declining fish stocks.
 They are also responding by turning to new, unexploited fisheries.
 Problems associated specifically with overfishing species low in the food web.
 The first is that these species are food for higher species.
 A second problem is that it allows the proliferation of other organisms low on
the food web.
 There are also indirect problems related to overfishing:
Chapter 15 Pages 15-36 & 15-37
The State of the World’s Fisheries – A Bleak Picture
 The fishing industry has become more efficient and blind to the threat.
 1. Humans aren’t the only organisms eating fish. Alaskan stellar sea lions are in
decline. The decline is thought to be the result of heavy commercial fishing
for pollock.
 2. By-catch is the unintentional capture of organisms.
 Estimates indicate this accounts for 25% of the catch. By-catch involves not only fish, but birds,
mammals, fish, and reptiles.
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 In June 2003, the Pew Ocean Commission, a respected group of US
scientists, wildlife advocates, natural resource managers, and politicians made
these four recommendations to restore US fisheries as sustainable biological
resources.
Chapter 15 Pages 15-37 & 15-38
The State of the World’s Fisheries – A Bleak Picture
Recommendations for Sustaining the World’s Fisheries
 1. Make the principal objective of US fisheries policies the protection of
marine ecosystems.
 2. Create an independent government agency responsible for managing
ocean resources.
 3. Invest in more marine research over the next five years. The commission
recommended doubling current funding.
 4. Establish a network of marine reserves or protected areas.
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Commercial Fishing Methods
Chapter 15 Pages 15-39 to 15-42
Commercial Fishing
Five Primary
Methods of
Commercial
Fishing
The Economics of Commercial Fishing
 It costs more to catch fish than is made from selling fish. Fishing fleets spend
about $124 billion to catch $70 billion in fish. The fishing industry survives
because of global government subsidies.
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The Origin of Territorial Waters
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In 1604, Dutch jurist Hugo Grotius wrote De Jure Praedae (On the Law of Prize and
Booty), the most important part of which was a chapter defending free access to the sea by
all nations. It took about 100 years, but finally it was internationally recognized.
Nations agreed to territorial water over which coastal nations had complete control.
The seaward boundary was set at 5 kilometers (3 miles), not coincidentally the
maximum effective range for cannon fire at the time. Beyond this limit was the high sea
(international waters) belonging to no one.
The Truman Proclamation
Chapter 15 Pages 15-43 & 15-44
Who Owns the Sea?

In 1945, President Harry Truman issued this proclamation claiming all physical and
biological resources on the continental shelf of the continental United States.
 Very quickly other nations followed suit.
 The proclamation changed the concept of international waters by widening the
concept of territorial water.
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Exclusive Economic Zones
 UNCLOS is the United Nations Convention of the Law of the Sea.
 It established the concept of the exclusive economic zone (EEZ). A nation’s EEZ
extends 370 kilometers (200 nautical miles) from the shoreline.
 Within EEZ, a nation has complete control of all resources, economic activity, and
environmental protections.
Chapter 15 Pages 15-44 to 15-46
Who Owns the Sea?
 Areas beyond the EEZs are the high seas or international waters belonging to no
one country.
 One of the more controversial aspects of UNCLOS was the establishment of the
International Seabed Authority plan. This plan said that mineral wealth recovered
from the seabed in international waters must be shared internationally.
 Because mineral wealth is to be shared internationally, the US, Canada, and Great Britain have
not ratified the UNCLOS treaty.
 In 1983, the US proclaimed its own EEZ within 200 nautical miles of its coasts.
This proclamation shares the limits, but omits provisions about shared
resources in international waters. Several other countries that have not ratified
UNCLOS have similarly declared EEZs of their own.
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The Ultimate Resource
Chapter 15 Pages 15-46 & 15-47
Biodiversity and the Future
 Biodiversity is the concept that the preservation of the Earth and ecosystems
relies on the broad genetic diversity of all the organisms on Earth.
 We never know when losing one or more species is losing too many or just how
important each single species is or when losing this species is the one
that counts.
 The importance of biodiversity is that every organism is a biological
resource. Even if there is no direct use of an organism, it is important
because it is part of what keeps life going.
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