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Law of the Sea
Treaties regarding ownership andexploitation of the marine resourcesratified during the last 50 years
Truman extended U.S. control of themarine resources from the shoreline toa depth of 100 fathoms
1958 and 1960 Geneva Conventions onthe Law of the Sea resulted in a treaty
that placed the control of the sea bed,sea bed resources, and waters of thecontinental shelf under the country thatowns the nearest land
1982 U.N. Draft Convention on the
Law of the Sea
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1982 U.N. Draft Conventionon the Law of the Sea
Territorial waters extend seaward for 12nautical miles from the coast and are underdirect jurisdiction
An exclusive economic zone (EEZ) thatextends for 200 nautical miles offshore orto the edge of the continental shelf (if thatis farther), giving nations the right toregulate fishing, mineral resources,pollution and research
The right of vessels to free and innocentpassage outside of the territorial waters andthrough international straits that lie withinterritorial waters
That all private exploitation of mineral
resources beyond the EEZs must beapproved by the U.N. International SeabedAuthority and that part of the revenue fromthe resources will be shared with thedeveloping nations
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EEZ
The U.S. has the worlds largestEEZ because of the large areassurrounding various islandpossessions and states
The U.S.s EEZ is 30% larger thanthe land area of the U.S.
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Exclusive Economic Zones
(EEZ)
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U.S. EEZ
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Mineral Resources Petroleum, Oil, and Gas
Gas Hydrates Sand and Gravel
Manganese Nodules Cobalt Deposits
Phosphorus
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Petroleum Complex mixture of hydrocarbons
Hydrocarbon = combination of hydrogen and carbon with various
amounts of nitrogen and metals Oil as it comes from the ground is
called petroleum or crude oil Composition varies greatly depending
on the geologic history Smaller hydrocarbons are less dense
and lighter Oil can be separated into various
densities by distillation because oils of different densities evaporate at differenttemperatures
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Petroleum, Oil and Gas Hydrocarbons derived from
sedimentary rocks, which weredeposited in quiet, productiveregions with anoxic bottom waters in
which the remains of phytoplanktonaccumulated Deep burial resulting in high
temperature and pressure convertedthe organic remains to hydrocarbons
Initially oil, but higher temperaturesand pressure, methane is generated
Pressure forced the oil and gas fromthe source rock into water-filledporous and permeable strata above
Oil and gas accumulated, forming alarge deposit usually sandstone
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Oil and Gas Deposits
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How oil is found
Location of possible accumulationsof oil and gas can be determinedusing seismic reflection andrefraction methods to determine theconfiguration of rock layers
This only indicates the potential totrap oil and gas, not if oil and/or gasis present
Large reserves in ANWR and Marsin Gulf of Mexico (but smallcompared to U.S. consumption)
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Gas Hydrates
Unusual hydrocarbon deposits thatconsist of frozen water moleculesentrapping a single methanemolecule
Occur in polar sedimetns and indeposits of the continental slopebetween the depths of 300 and 500m where cold water is in contactwith the sea floor
Deposits contain incredibly largeamounts of gas, but no economicalmethod for its recovery at present
North Carolina deposits 350 x
annual energy consumption of theU.S. (6.6 billion barrels/yr)
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Sand and Gravel
Natural aggregates of unconsolidatedsediment with grain size greater than0.065 mm in diameter
Sand and gravel accumulate in highenergy environments where strongcurrents and/or waves prevail
Relict sediments on continental shelf from when sea level was lower
Materials used for construction of
roads and building Materials used to replenish beaches Mining sand and gravel threatens
both the benthic and pelagiccommunities and introduces largeamounts of material into suspension
Only 1% of sand and gravelpresently taken from offshore
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Sand and Gravel
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Manganese Nodules
Composed of about 20-30%
manganese, 10-20% iron oxide,1.5% nickel, and less than 1%copper, zinc and lead
Locally the nodules are veryabundant
Presently, no economical method of recovering them from the deep sea
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Cobalt Deposits Sides of many seamounts and islands
are enriched in cobalt between thedepths of 1000-2500 m
Cobalt is a strategic metal used inmaking jet engines
U.S. cannot produce sufficient cobaltto meet its needs
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Phosphorus
Phosphorus is required for growthby all organisms
Phosphate deposited generally formon submarine terraces where coastalupwelling generates highproductivity
Organic wastes and remainsaccumulate in the sediment and asthey decay they release phophoruscompounds, which precipitate asphosphate nodules
Nodules grow at the rate of about 1-20 mm/1000 yr
World consumption of phosphate is
about 150 million tons/yr Known supplies should last until
2050
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Living Resources
Fishing
Whaling Mariculture
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Fishing
Two types of fish are fished Pelagic live in water column Groundfish live on sea floor
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Fishing
Most of the ocean is sparselypopulated because of low nutrientavailability
Major fish production areas arecoastal waters and regions of upwelling
Because they are economic tocapture, major commercial fishes arethose which form large schools
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Ocean Fisheries
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Fishing Methods
To locate the fish Sonar Scouting vessels
Airplanes Satellites
Nets
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Drift Nets Controversial, because they capture
everything too large for the net andneedlessly kill many organisms
1989 U.N. Convention for theProhibition of Long Drift netsprohibits drift nets longer than 2.5km Compliance is voluntary Impossible to enforce
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Fishing Sustainability World ocean fish production appears
to have leveled at between 80-100million tons/yr
Maximum sustainable catchestimated to be 100 million tons/yr
Currently the expense to fishexceeds the profit from the sale of fish Fishing industries survive only through
government subsidy
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Overfishing
Removing a living resource from thesea faster than it can replace itself
If continued long enough, the
resource will collapse Overfishing is possible today
Technology has made it easier to locatelarge schools of fish and to directfishing fleets to those locations
Mismanagement of policies related tosustaining fish populations
Fishermen resist quotas and misreportcatches
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Fishing Harvests
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Maximum Sustainable Yield
Theoretical maximum amount of fish that can be removed from apopulation without significantly
interfering with the populationsability to renew itself
Based on biological factors such aspopulation dynamics, food webs,
and spawning success, and thefishing effort required to produce agiven catch
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Problems with determining
a maximum sustainableyield Under-reporting the amount of fish caught Natural fluctuations of populations due to
predation and food supply The inherent difficulty in determining the
size of fish populations The unknown impact of discard fish (those
returned to the sea because they are too
small or of poor quality) on the population Politics frequently result in altering the
scientifically determined maximumsustainable yields to meet political ends
Should be replaced by precautionary
principle, which is to avoid anything whichmay damage or negatively impact a fishery
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Mariculture Marine agriculture or fish farming Finfish, shell fish, or algae Currently, about of the fish
consumed has spent part of its life inmariculture
For some species, this percentage ishigher
For mariculture to be economicallyviable, the species must be Marketable Inexpensive to grow Trophically efficient
At marketable size within 1to 2 years Disease resistant
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Mariculture vs. Fishing
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The Human Presence in theOcean
Pollution
Hydrocarbons natural and spills Municipal and Industrial Wastes Ocean Dredging and Mining
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Pollution
Introduction by man, directly orindirectly, of substances of energyinto the environment, resulting in
deleterious effects such as harm toliving resources, hazards to humanhealth, hindrance of marineactivities, including fishing,impairing quality for use of seawater and reduction of amenities
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Pollutants
Manufacturing,transportation,
agriculturalfertilizers, and
pesticides
NoneSyntheticChemicals
Municipaleffluents,
agriculturalfertilizers
Rivers,upwelling,
atmosphere,bacterial
decomposition
Nutrients
Industrial andmunicipaleffluents
Volcanoes,rivers, sedimens,
weathering of rocks
Heavy Metals
Transportation,production,
aerosols
Seeps, rivers,volcanoes,
atmosphere,bacteria
Hydrocarbons
HumanSource
NaturalSource
Pollutant
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Extent of Pollution
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Studying Pollution
Need to have a baseline from whichto measure mans impact upon theenvironment, because some of what
is considered to be pollution may beoccurring naturally and not causedby man
Pollutants are eventually broken
down by various oceanographic andbiological processes
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Parts of the ocean wherepollution is conentrated
Sea floor bottom of ocean Accumulation on bottom by settling or
by becoming attached to particleswhich settle
Mainly affects benthos
Pycnocline density gradientbetween surface and deep ocean Accumulation because pollutants are
too light to sink through dense bottomlayer
Often occurs in estuaries
Neuston layer air-water interface Mainly affects plankton
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Hydrocarbons
Only a small fraction of the oil in thesea comes from major oil tankeraccidents 31% from contaminated rivers 32% from tanker release as they pump
their bilges, incomplete burning of fuel,and general ship traffic
13% from leakage at coastal refineries 20% from natural oil seeps and
atmospheric fallout
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Transportation Routes forCrude Oil
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Hydrocarbon Fates
Altered in the environment Spreading Lighter than water so it floats Spreads to be film on top
Drift by currents and wind
Evaporation Light portion evaporates Dissolution
Soluble portion dissolves
Emulsification Heavy portion Forms into a water-oil mixture without
dissolving Globules which eventually form tar balls,
which wash ashore or sink
Sedimentation Attaches to particles and sinks to bottom
Biodegradation Broken down into CO 2 by bacteria Some ingested by larger organisms
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Hydrocarbon Fates
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Municipal and IndustrialEffluents
Humans produce over 20 billion tonsof wastes each year
Much of that is disposed of in theocean Most wastes from farmland, cities,
and industrial areas Most wastes enter ocean through
rivers All bodies of water have a natural
capacity to clean themselves of acertain amount of pollution
Dense populations can overwhelmthat
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Pollution Distribution
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Pollutant Fates
Diluted as it enters the oceandependent on waves and currents
Pollutant behavior depends on
temperature, density, and stability A contaminant plume is formed
upon release
Plume increases in size with distance
as the pollutant is diluter
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Pollutant Fates
Particulate matter will settle out,larger particles settle out first andclosest
Some material will concentrate at
pycnocline Influence of pollution decreases with
distance from the source
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Biota Distribution near
Outfall At the source
the bottom will consist of sludge No infauna
Farther from the source Dwarfed individuals
At even greater distance Fauna will be unusually abundant due
to large amounts of nutrients Fauna forms dense masses
At a great distance Fauna unaffected by the pollution
Normal density and normal size of individuals
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Municipal and Industrial
Wastes Sewage
Messy sludge of organic and inorganiccompounds
Heavy metals Elements such as lead, mercury,
cadmium, arsenic, and copper thatnormally occur in trace amounts butbecome toxic in larger dosages
Artificial biocides Man-made toxic chemical compounds
that do not occur naturally
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Bioaccumulation andBiomagnification
Bioaccumulation The process whereby organisms retain
and concentrate a toxic material withintheir body
Biomagnification The process whereby a toxic material
increases in concentration with eachtrophic level of a food chain
Results from bioaccumulation at eachtrophic level
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Sewage
Human waste is a major componentof sewage Organic matter Inorganic nutrients (nitrates and
phosphates) Pathogens
Disease-causing organisms such as bacteria,viruses and parasites
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Results of Sewage
If sufficient nutrients are released, aphytoplankton bloom can occur As dead phytoplankton sink to the bottom and
decompose, an excessive demand on oxygenoccurs
Biological oxygen demand (BOD) Water becomes hypoxic or anoxic Process called eutrophication
Resulting low oxygen content will killmost organisms on the bottom and in theaffected water column As herbivores are killed, there is less grazing More phytoplankton survive to reproduce and
generate an even greater BOD Eventually the food chain can be decimated
Eutrophication observed in lakes,
embayments, and even on sections of thecontinental shelf
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Heavy Metals
Normally added to the ocean insmall amounts through theweathering of rocks and volcanic
activity Manufacturing and industrial
processes greatly increase theamount of heavy metals released
Mercury, especially methyl mercury,is highly toxic because it is notbiodegradable Stored in the fatty tissues Damages the central nervous system
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and fishing
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Narragansett Bay
Hypoxic and anoxic conditions
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Artificial Biocides
Halogenated hydrocarbons ororganochlorines are common DDT
PCB Not biodegradable Remain for a long time
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DDT
Highly toxic Banned in most of the western world Use continues in some countries
Sprayed on crops and soil, muchwashes into rivers
Some remains airbornecontaminating rain and snow orsettling into the ocean
Has been detected in the muds of thedeep ocean and in the ice of Antarctica
Large lens off Los Angeles Miles in diameter, > 1 m thick
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PCB
Used in production of electricalequipment, paints, and adhesives
Released into the environment by
incineration and unregulateddisposal
Have been found throughout theocean environment
Hudson contaminated by GE
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Agricultural Wastes
Fertilizers and animal wastes washedoff fields into rivers
Eventually flow into ocean Act as fertilizer in ocean Cause eutrophication
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Ocean Dredging
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Ocean Dredging
80-90% of the material dumped atsea each year comes from dredging
If dredged material is clean, it is lessof a problem If material is dumped slowly, many
benthic organisms can work their wayto the surface through the new layer of sediment
If material is dumped too rapidly, theyare buried and killed
If the material is different than theoriginal, a different group of organismsmay colonize the area
Clean dredgings can be used toreplenish beaches
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Contaminated Dredge
Sediments Represent an initial and long-term
source of pollutants Come from harbors and rivers,
Dredging the contaminatedsediments reintroduces pollution intothe water at the site of the dredging
Dumping the sediment releasespollution at the dumping site
As the dumped sediment compacts,contaminated pore water escapes andcontaminates the water column
Storms and currents disturb thesediment and reintroduce pollution
To minimize reintroduction,contaminated sediment is frequentlycapped
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Ocean Mining Mining will most likely be
accomplished with a hydraullicpumping system that will vacuumwater, sediment and organisms from
the sea floor and bring them to thesurface
Most of these organisms will die
Large areas of the sea floor will be
disrupted and stripped of life Sediment released at the surface will
create a massive sediment plume If it remains suspended, it will reduce
photosynthesis due to lower light frothe increased turbidity
Rapid sinking could bury organisms
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Name the 5 oceans
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