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OUR OCEAN PLANET

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Title: OUR OCEAN PLANET


1
OUR OCEAN PLANET
  • OUR OCEAN PLANET
  • SECTION 10 HUMANS AND THE OCEAN

2
REVISION HISTORY
Date Version Revised By Description
Aug 25, 2010 0.0 VL Original
3
10. HUMANS AND THE OCEAN
10. HUMANS AND THE OCEAN
4
10. HUMANS AND THE OCEAN
This section discusses human interactions with
the ocean. We start with a brief history of
people and the ocean. This is followed by a
description of our attempts to explore the ocean.
We also describe some of the fields and
technologies involved in studying the ocean. We
then continue by describing ocean conservation by
outlining some of the main reasons we need a
healthy ocean. Finally, we describe some of the
problems we are causing and some possible
solutions to these problems.
5
10.1 PEOPLE AND THE OCEAN
10.1 PEOPLE AND THE OCEAN
6
10.1 PEOPLE AND THE OCEAN
10.1 PEOPLE AND THE OCEAN The following presents
a brief history of people and the ocean. This is
followed by a description of our attempts to
explore the ocean and some of the fields and
technologies involved in studying the
ocean. 10.1.1 History PRE-1000 AD Egyptians
(4,000 BC) The Egyptians develop shipbuilding and
ocean piloting skills. Phoenicians (1,000-600
BC) The Phoenicians explore the Mediterranean
Sea, reach England, and circumnavigate Africa by
following the coastline. Greeks (384-192
BC) Aristotle (384-322 BC) describes how sharks
produce live young and recognizes that dolphins
are not fish. Through the use of trigonometry,
Eratosthenes (276-192 BC) accurately determines
the circumference of the Earth.
7
10.1 PEOPLE AND THE OCEAN
Romans (54 BC-30 AD) Seneca puts forward his
hypothesis on the hydrological cycle of
water. Ptolemy (150 AD) Ptolemy the Greek
compiles the Roman World Map which incorporates
the basic lines of longitude and
latitude. Polynesians (300-800 AD) The
Polynesians spread east across the Pacific
reaching New Zealand, Hawaii, and Easter
Island. The Venerable Bede (673-735 AD) The
English monk, Bede, describes the lunar
influences on tidal cycles and recognizes the
monthly tidal variations.
Interesting! Bluetooth technology is a short-range wireless communications technology intended to replace the cables connecting portable and/or fixed devices, and allows a wide range of devices to connect and communicate with each other. The name "Bluetooth" is from the 10th century Danish King Harald Blatand (or Harold Bluetooth in English) who was critical in uniting Norway, Sweden and Denmark just as Bluetooth technology hopes to allow different devices such as computers, keyboards, earpieces and phones to work together.
8
10.1 PEOPLE AND THE OCEAN
Vikings (ca. 790-1066 AD) The Vikings were
Scandinavian seafaring traders, warriors and
pirates who raided and colonized wide areas of
England, Scotland, Normandy, and other parts of
Europe and North America from the late 8th to
11th centuries. King Harold Godwinson, the last
Anglo-Saxon king of England, who was killed
during the Norman conquest of England in 1066 AD,
was descended from Danish Vikings. Some of the
invading Normans were also descended from Danes
and Norwegians that were given lands in Normandy
in the 8th century. The Vikings used their famed
longships to travel as far north as Iceland and
Greenland, east to Constantinople, and west to
Newfoundland. In 982 AD, Eric the Red discovered
North America when he landed on Baffin Island in
Canada. Later, in 995 AD, his son, Leif Ericson
established Vinland, a settlement in
Newfoundland. Generally, the Norwegians expanded
to the north and west to places such as Iceland
and Greenland, the Danes to England and France,
and the Swedes to the east. These nations,
although distinct, were similar in culture and
language and only after the end of the Viking Age
did the separate kingdoms acquire distinct
national identities.
9
10.1 PEOPLE AND THE OCEAN
1000 AD-1499 AD Zheng He (1371-1433) Between
1405 and 1433, the Ming government of China
sponsored a series of seven naval expeditions to
impose imperial control over trade and establish
Chinese presence in the Indian Ocean
basin. Zheng He was placed as the admiral in
control of the expeditions and the huge fleet and
armed forces that undertook them. His first
voyage consisted of a fleet of 317 ships holding
almost 28,000 troops. Many of these ships were
mammoth nine-masted "treasure ships" which were
by far the largest ships the world had ever seen
at the time. On the first three voyages, Zheng
He visited southeast Asia, India, and Ceylon (Sri
Lanka). The fourth expedition went to the Persian
Gulf and Arabia, and later expeditions ventured
down the east African coast as far as Malindi
(Kenya). Zheng He died during the treasure
fleet's last voyage. His missions showed
impressive organizational capability and
technological might but they did not lead to
significant trade. Chinese merchants continued to
trade in Japan and southeast Asia and Imperial
officials gave up any plans to maintain a Chinese
presence in the Indian Ocean.
10
10.1 PEOPLE AND THE OCEAN
Christopher Columbus (14511506) Christopher
Columbus was a navigator and explorer and one of
the first Europeans to explore the Americas after
the Vikings. Though not the first to reach the
Americas from Europe, Columbus' voyages led to
general European awareness of the hemisphere and
the successful establishment of European cultures
in the New World. Columbus' voyages across the
Atlantic Ocean began a European effort at
exploration and colonization of the Western
Hemisphere. While history places great
significance on his first voyage of 1492 in his
ship, the Santa Maria, he did not actually reach
the American mainland until his third voyage in
1498. Instead, he made landfall on an island in
the Bahamas Archipelago while trying to find a
sea route to India.
Interesting! Columbus mistaken belief that he had reached India resulted in misnaming native Americans as Indians. In modern times, attempts have been made to correct this by referring to indigenous peoples as Native Americans. As a result, terms such as Red Indians and Carib Indians are falling out of use.
11
10.1 PEOPLE AND THE OCEAN
Columbus was also probably not the earliest
European explorer to reach the Americas and there
are accounts of European transatlantic contact
prior to 1492 (most notably by the Vikings).
Nevertheless, Columbus's voyage came at a
critical time of growing national imperialism and
economic competition between developing nation
states seeking wealth from the establishment of
trade routes and colonies.
12
10.1 PEOPLE AND THE OCEAN
Leonardo Da Vinci (1452-1519) Leonardo Da Vinci
observed and recorded the movements of waves and
currents. From his observations of fossils he
deduced that the sea levels must have been higher
in the past. Ferdinand Magellan
(14801521) Ferdinand Magellan was a Portuguese
explorer who, while in the service of the Spanish
crown, tried to find a westward route to the
Spice Islands of Indonesia. Magellan is the
first European explorer to enter the Pacific
Ocean through what are now known as the Straits
of Magellan at the southern tip of South America
on the first successful circumnavigation of the
Earth. Magellan was killed in the Philippines
in 1521 on his final westward voyage. After
Magellans death, the voyage was continued and
completed by Sebastian del Cano in 1522. It is
interesting to note that of the 270 crew members
who set out with Magellan to circumnavigate the
Earth, only 18 completed the voyage and returned
to Spain a testament to the hard conditions
endured by Magellan and his crew.
13
10.1 PEOPLE AND THE OCEAN
1500 AD-1899 AD Sir Francis Drake (ca.
15401596) Drake was an Elizabethan sailor,
navigator, privateer, slave trader, politician
and the first Englishman to circumnavigate the
globe. In 1588, he was a vice admiral in the
fleet that defeated the Spanish Armada. His
exploits against the Spaniards were
semi-legendary and made him a hero to the English
but not the Spaniards. To the Spaniards, he was
known as "El Draque" (from the old Spanish
meaning "the Dragon" derived from the Latin
draco, meaning serpent) for his actions. He
died of dysentery off the coast of Puerto Rico in
1596. Gerardus Mercator (1569) Gerardus Mercator
constructs the Mercator projection map which
greatly improved accuracy for navigation
although it distorts the relative size of the
continents. Admiral Sir Henry Morgan (ca.
1635-1688) Admiral Sir Henry Morgan was a Welsh
privateer, who made a name in the Caribbean as a
leader of buccaneers. He was among Wales's most
notorious and successful privateers. Robert Boyle
(1674) Robert Boyle carries out pioneering
oceanographic measurements on temperature,
salinity, pressure and depth.
Interesting! Boyles Law states that for a fixed amount of gas at constant temperature, the pressure and volume of the gas are inversely proportional to one another. This can be written P 1 / V Thus, under ideal conditions, when you double the pressure on a gas, the volume is halved.
14
10.1 PEOPLE AND THE OCEAN
Greenwich Meridian Established (1675) The Royal
Observatory in Greenwich, England is established
and the line of longitude is set at 0 (the
Greenwich Meridian). Edward Teach (ca.
16801718) Edward Teach, better known as
Blackbeard, was a notorious English pirate in the
Caribbean Sea and western Atlantic during the
early 18th century, a period referred to as the
Golden Age of Piracy. Blackbeard often fought,
or simply showed himself wearing a big feathered
tricorn hat, and carrying several swords, knives,
and pistols. It was reported that he had hemp
and lighted matches woven into his black beard
during battle. Blackbeard is the archetype of
the seafaring pirate. Captain James Cook (1728
1779) Captain James Cook is considered one of the
worlds greatest explorers and navigators. His
three major voyages of discovery provided the
English with unprecedented information about the
Pacific Ocean and its island inhabitants. He
also searched for the great southern continent of
Terra Antarctica. Although he did not discover
Antarctica, he was the first navigator to cross
the Antarctic Circle in 1773. His meticulous
mapping skills pioneered the way for the success
of future explorations and his voyages lead to
the establishment of colonies throughout the
Pacific. In 1771, Cook was also the first ship
commander to prevent scurvy by serving his crew
fruit and sauerkraut.
Interesting! Eating fresh fruit and vegetables (especially citrus fruits, such as limes) helps prevent scurvy. In order to prevent scurvy killing his crew on their long voyages, Captain Cook ordered his crew to eat limes. This is why the English are sometimes nicknamed limeys.
15
10.1 PEOPLE AND THE OCEAN
Horatio Nelson (1758-1805) Vice Admiral Lord
Nelson was famous for his leadership during the
Napoleonic Wars, most notably at the Battle of
Trafalgar, a decisive British sea victory in the
war, during which he lost his life. Nelson went
against the conventional tactics of the time by
sailing his fleet through the enemy's lines
rather than sailing broadside to each other and
firing cannon until one side retreated. Nelson
was noted for his ability to inspire and bring
out the best in his men to the point that it came
to called the Nelson Touch". His actions during
these wars meant that he was revered like few
military figures have been throughout British
history. His memory lives on in numerous
monuments, most notably Nelson's Column, which
stands in the centre of Trafalgar Square in
London. Gulf Stream Ocean Charts Published
(1769-1770) Benjamin Franklin publishes the first
ocean charts of the Gulf Stream to help the
passage of ships across the Atlantic Ocean. Deep
Water Life In the Arctic Ocean (1817-1818) Sir
John Ross discovers living organisms at a depth
of 1.8 km (1.1 miles) near Baffin Island in the
Arctic Ocean.
16
10.1 PEOPLE AND THE OCEAN
Charles Darwin (1809-1882) Charles Darwin was an
English naturalist. After becoming an eminent
scientist in geology, he proposed and provided
scientific evidence for his theory that life
evolved over time from a few common ancestors
through the process of natural selection. The
theory of natural selection came to be widely
seen as the primary explanation of the process of
evolution in the 1930s and forms the basis of
modern evolutionary theory. In modified form,
Darwins scientific discovery remains the
foundation of biology as it provides a unifying
logical explanation for the diversity of
life. Darwin five-year voyage on the Beagle to
the Galapagos islands and South America allowed
him to collect and gather data that would help
him formulate the theory of evolution. Puzzled
by the geographical distribution of wildlife and
fossils collected on the voyage, Darwin
investigated the transmutation of species and
conceived his theory of natural selection in
1838. Having seen others attacked as heretics
for such ideas, he confided only in his closest
friends and continued extensive research to meet
anticipated objections. His research was still
in progress in 1858 when Alfred Russell Wallace
sent him an essay which described a similar
theory prompting immediate joint publication of
both of their theories.
17
10.1 PEOPLE AND THE OCEAN
1839-1843 Sir James Clark Ross (1800-1862)
discovers living organisms at a depth of 7 km
(4.3 miles) in Antarctic waters. 1835-1910 Victor
Hensen makes important discoveries on the nature
of plankton and pioneers techniques for plankton
study. 1855 In 1855, Matthew Maury (1806-1873),
an American, compiled wind and current data to
help shipping and published his findings in the
Physical Geography of the Seas. Maury becomes
known as the Father of Oceanography. HMS
Challenger (1872-1876) The naturalist, Charles
Wyville Thomson, conducts worldwide scientific
investigations aboard HMS Challenger. These are
the first serious attempts to study the bottom of
the ocean and his voyages collected and
classified almost 5,000 new species of marine
life. 1884 The Marine Biological Association is
established in England to study coastal ecology.
18
10.1 PEOPLE AND THE OCEAN
1892 The Norwegian polar explorer, Fridtjof
Nansen (1861-1930) has the ship Fram specially
built to withstand ice-entrapment. The drift of
the ship confirms there is no Arctic
continent. 1895-1898 The American, Joshua
Slocum, becomes the first man to circumnavigate
the world single-handed in his yacht
Spray. 1900 AD-TODAY 1902 The Danes set up the
International Council for the Exploration of the
Seas (ICES) to investigate the oceanography and
fisheries of the North Sea. 1908 The Scripps
Institute of Oceanography is established in the
USA. 1912 The German scientist, Alfred Wegener,
proposes his theory of continental
drift. 1920-1940 The British-led Discovery
Investigations carry out extensive work in many
regions of the southern oceans. The results
establish modern Antarctic marine research.
Interesting! The Arctic is a frozen ocean there is no Arctic continent. In contrast, Antarctica is a frozen continent.
19
10.1 PEOPLE AND THE OCEAN
1925-1927 A German expedition directed by George
Wurst aboard the ship Meteor makes detailed
studies of the oceanography of the Atlantic
Ocean. Many modern oceanographic techniques were
first used on these voyages. 1930 The Woods Hole
Oceanographic Institute is established in Cape
Cod, Massachusetts, USA. 1934 William Beebe
(1877-1962) was an American naturalist, explorer,
and author. His interest in deep-sea exploration
led to the development of the bathysphere, a
spherical metal diving vessel, with Otis Barton.
In 1930, he descended 183 m (600 ft) off Nonsuch
Island in Bermuda, where in 1934 he made a record
descent of 923 m (3,028 ft). Beebe made a total
of 35 dives in the bathysphere. 1943 Jacques
Cousteau (1910-1997) was a French naval officer,
explorer, ecologist, filmmaker, scientist,
photographer and researcher. He co-developed the
aqua-lung and pioneered marine conservation, and
is widely regarded as the father of modern scuba
diving.
Interesting! Cousteaus research ship Calypso is named after a nymph in Greek mythology who kept Odysseus on her island for seven years.
20
10.1 PEOPLE AND THE OCEAN
Cousteau started skin diving with Frédéric Dumas
and Philippe Tailliez in 1938. In 1943, he and
Émile Gagnan tried out the first prototype
aqua-lung. This made lengthy underwater
exploration possible for the first time, helped
improve our knowledge of the underwater world,
and opened the door to many people being able to
dive. Before the echolocation abilities of
porpoises were discovered, Cousteau suggested
that they might exist. In his first book, the
Silent World (1953), he reported that a group of
porpoises were following his research vessel in
the Straits of Gibraltar. Cousteau moved the
ship a few degrees off the optimal course to the
center of the strait and the porpoises followed
for a few minutes before diverging towards
mid-channel again. It was evident they knew
where the optimal course lay. Cousteau correctly
concluded that cetaceans must use sonar to help
them navigate. 1946 The International Whaling
Commission (IWC) is set up under the auspices of
the United Nations to collect whaling information
and to regulate the shore-based whaling industry
and pelagic whaling fleets.
Interesting! Sonar is the generic name of the technology that is used to locate objects underwater. Sonar systems are of two basic types - active and passive. In active sonar, the system emits a pulse of sound and then the operator listens for echoes. In passive sonar, the operator listens to sounds emitted by the object one is trying to locate. SONAR is an acronym and means SOund Navigation And Ranging
21
10.1 PEOPLE AND THE OCEAN
1947 Thor Heyerdahl sails from Peru across the
Pacific on the balsa raft Kon Tiki partly to
prove that Pacific islands could have been
reached by early sailors from South America. He
campaigned to make people aware that all of the
oceans are linked and that what we throw into the
sea will find its way all over the
world. 1958 The nuclear submarine, USS Nautilus,
commanded by Cdr. William Andersen, reaches the
North Pole under the ice. 1960 The Swiss
scientist, Auguste Piccard, developed the
un-tethered bathyscaphe Trieste. Jacques
Piccard and Donald Walsh descend to the deepest
part of the worlds oceans to a depth of 10,915 m
(35,810 ft) in the Mariana Trench, off the island
of Guam in the Pacific Ocean. 1959-1965 The
International Indian Ocean Expedition (IIOE)
investigates the oceanography of the Indian Ocean.
22
10.1 PEOPLE AND THE OCEAN
1966 The first supertanker disaster, Torrey
Canyon, occurs off the coast of southwest
England. About 31,000,000 gallons of oil leaked
from the ship killing much of the marine life
along the whole of the south coast of Britain and
Normandy shores of France. Since then other
major oil-related disasters in the marine
environment include the Amoco Cadiz, Exxon Valdez
and oil spills in the Persian Gulf resulting from
the Gulf War. 1968-1975 The US National Science
Foundation organizes the Deep Sea Drilling
Project (DSDP) to investigate the ocean crust.
It confirms the theory of sea floor
spreading. 1970s The United Nations initiates
the International Decade of Ocean Exploration
(IDOE). 1972 The Geochemical Ocean Sections Study
(GEOSECS) is organized to study ocean chemistry
and biochemical recycling of chemical
substances. 1977 Manned American submersibles
discover remarkable deep sea communities
associated with hydrothermal vents along sea
floor ridges.
23
10.1 PEOPLE AND THE OCEAN
1978 The first remote-sensing oceanographic
satellite (SEASAT-A) is launched to study the
oceans. 1980s The Coordinated Ocean Research and
Exploration Sections program (CORES) is
established by the UN to continue work from the
IDOE investigations of the 1970s. Sylvia Earle
(1935- ) Sylvia Earle is an American
oceanographer. In 1979, she made an open-ocean
pressurized JIM suit dive setting a women's depth
record of 381 m (1,250 ft) she also holds the
women's record for a solo dive in a deep
submersible (1,000 m, 3,280 ft). Earle has led
more than 400 expeditions worldwide and has over
7,000 hours underwater in connection with her
research. An expert on the impact of oil spills,
she was called upon to lead several research
trips during the Gulf War and following the
spills of the ships, Exxon Valdez and Mega Borg.
She is the author of more than 125 publications
on marine science and technology. She has
participated in numerous television productions
and given scientific, technical, and general
interest lectures in more than 60 countries.
Earle was named Time magazine's first "hero for
the planet" in 1998.
24
10.1 PEOPLE AND THE OCEAN
Robert Ballard (1942- ) Robert Ballard (1942- )
is an oceanographer most noted for his work in
underwater archaeology. He is most famous for
the discoveries of the wrecks of the Titanic in
1985, the battleship Bismarck in 1989, and the
wreck of the aircraft carrier USS Yorktown in
1998. In 2002 he discovered the wreck of John F.
Kennedy's PT-109.
REFERENCES FURTHER READING http//www.bluetooth.
com/Bluetooth/ - Bluetooth http//en.wikipedia.org
/wiki/Robert_Ballard - Robert Ballard http//www.n
ationalgeographic.com/pirates/bbeard.html -
Blackbeard http//en.wikipedia.org/wiki/Jacques-Yv
es_Cousteau - Jacques Cousteau http//en.wikipedia
.org/wiki/Christopher_Columbus - Christopher
Columbus http//www.bbc.co.uk/history/british/empi
re_seapower/captaincook_01.shtml - Captain
Cook http//www.bbc.co.uk/history/historic_figures
/da_vinci_leonardo.shtml - Leonardo Da
Vinci http//www.bbc.co.uk/history/historic_figure
s/drake_francis.shtml - Francis
Drake http//en.wikipedia.org/wiki/Sylvia_Earle -
Sylvia Earle http//en.wikipedia.org/wiki/Ferdinan
d_Magellan - Magellan http//www.bbc.co.uk/history
/historic_figures/magellan_ferdinand.shtml -
Magellan http//www.lboro.ac.uk/departments/hu/erg
sinhu/aboutergs/torrey.html - Torrey
Canyon http//en.wikipedia.org/wiki/Viking -
Vikings http//www.pbs.org/wgbh/nova/vikings/ -
Vikings http//en.wikipedia.org/wiki/Zheng_He -
Zheng He http//www.pbs.org/wgbh/nova/sultan/explo
rers2.html - Zheng He http//www.dosits.org/scienc
e/ssea/1a.htm - Sonar http//www.bbc.co.uk/history
/historic_figures/ - Historic figures
25
10.1 PEOPLE AND THE OCEAN
10.1.2 Final Frontier The ocean is the last and
largest unexplored place on Earth less than 5
of it has been explored. This is the great
frontier for the next generations explorers and
researchers, where they will find great
opportunities for inquiry and investigation. Part
of the reason for this is simply the challenge
of the enormous pressures at depth. It has only
really been in the last 100 years or so that
human technology has allowed us to begin to
explore and study the deep ocean. Probably the
first serious attempt to study the deep ocean was
undertaken by the crew members of HMS Challenger
between 1872 and 1876. The scientists on board
returned with over 4,000 new species including
the first ever anglerfish to be retrieved from
the depths.
Ocean Literacy Principle 7(a) The ocean is the last and largest unexplored place on Earthless than 5 of it has been explored. This is the great frontier for the next generations explorers and researchers, where they will find great opportunities for inquiry and investigation.
26
10.1 PEOPLE AND THE OCEAN
DIVING Divers today typically fall into two main
groups 1. Recreational Scuba Diving Normally
To 45 m (150 ft) Recreational scuba divers
typically use a tank of compressed air to dive
the oceans. The use of compressed air restricts
the maximum depth and duration of a dive. A
diver breathes compressed air normally at depth
and has no sense that anything is different.
However, changes are occurring within the body.
Nitrogen is entering the blood stream and begins
to build up the longer the diver stays down,
the more compressed nitrogen is in the
bloodstream. When a diver surfaces and the
pressure decreases, nitrogen begins to come out
of the blood and small bubbles may form.
Normally, this is not a problem. However, if the
diver has stayed down too long, gone too deep, or
has come up too fast, the bubbling can cause
serious problems. Bubbles can become lodged in a
critical area of the body (e.g. a divers brain
or heart), and cause embolisms, decompression
sickness or the bends.
27
10.1 PEOPLE AND THE OCEAN
Divers typically wear a neoprene wetsuit or a dry
suit to keep warm. A wetsuit works by trapping a
thin layer of water between the suit and the
divers skin. This thin layer of water is warmed
by the body and, because the wetsuit is
form-fitting, water only passes through slowly.
Typically, a thick wetsuit will keep a diver
comfortable to a water temperature of 10C
(50F). For colder waters, dry suits are used.
These are sealed so no water enters the suit. A
diver wears ordinary clothing under the suit and
stays dry throughout the dive. Dry suits are
suitable for cold water temperatures of 0C
(32F). Both wetsuits and dry suits make a diver
buoyant so divers carry weight to keep them down.
The ideal is for a diver to be neutrally
buoyant where he is neither going up or down. A
diver must learn and practice maintaining neutral
buoyancy. Good buoyancy control is particularly
important when diving on reefs so that divers do
not crash into and break pieces of coral.
Interesting! SCUBA is an acronym and means Self Contained Underwater Breathing Apparatus
Interesting! Serious scuba diving injuries are usually caused a diver staying down too long, diving too deep or surfacing too quickly.
28
10.1 PEOPLE AND THE OCEAN
2. Commercial Research Diving To 600 m (2,000
ft) Commercial and research divers also utilize
scuba diving equipment but may use different
quantities and combinations of breathing gases to
prolong the dive time and increase depth. Divers
that need to dive and work even deeper will
sometimes use pressurized NEWT or JIM suits.
NEWT suits are armored thick-walled suits that
completely enclose divers and resist water
pressure. When underwater, the diver breathes
air at normal pressure as if inside a submarine.
This means a diver can go deeper without having
to undergo decompression. NEWT suits are used in
oil exploration to depths of 365 m (1,200 ft).
Joints in the arms and legs allow the diver to
move. JIM suits are also armored thick-walled
suits that completely enclose a diver. Divers
breathe air at normal atmospheric pressure. A
JIM suit protects a diver from the crushing water
pressure to depths of up to 600 m (2,000 ft) and
is named after Jim Jarret who first wore the suit
in 1969.
29
10.1 PEOPLE AND THE OCEAN
SUBMARINES The maximum depths of modern military
submarines are classified and accurate
information is not easy to obtain. However, it
seems that the largest, deep-diving,
military-style submarine is the nuclear-powered
Soviet submarine K-278 Komsomolets which have
hulls made of titanium. This made them very
expensive to build but they were able to dive
much deeper than the best American nuclear
submarines which are of high-grade steel. The
Komsomolets is estimated to be able to dive 1,300
m (4,265 ft). In contrast, American Sea Wolf
class submarines have an estimated crush depth of
about 730 m (2,400 ft). It is interesting to
note that our most powerful submarines only reach
about one-tenth of the maximum depth of the ocean
at 11,000 m (7 miles) with most operating
shallower than 1,000 m (3,300 ft).
30
10.1 PEOPLE AND THE OCEAN
SUBMERSIBLES The following outlines some of the
most famous submersibles used to study the deep
ocean. Some, like Alvin, are almost household
names while others may be less familiar 1.
Beebe Bartons Bathysphere In the 1930s, Dr.
William Beebe became the first person to observe
deep sea animals in their natural habitat. The
terrifying, fanged creatures that we now
recognize as deep sea fish were first viewed by
Beebe. 2. Johnson Sea Link One of the most
recent manned submersibles is the Johnson Sea
Link (JSL) built and operated by the Harbour
Branch Oceanographic Institute in Florida. It
has a front sphere of plexiglass which limits it
to a depth of 1,000 m (3,300 ft) but it gives an
observer an unrestricted view of mid-water life.
31
10.1 PEOPLE AND THE OCEAN
3. Nautile The Nautile is a French submersible
that measures about 8 m (26 ft) in length. It
was used to recover objects from the seabed
surrounding the wreck of the Titanic. Only a
submersible could dive deep enough to reach the
Titanic, 3,780 m (2.3 miles) down. The Nautile
is, essentially, a titanium sphere that is able
to withstand the immense pressure at these
depths. Extra-thick curved plexiglass portholes
flatten on the dive from the deep water pressure.
Nautile can stay down for about 8 hours and has
space for three people (a pilot, co-pilot and an
observer). 4. Alvin In 1964, the Woods Hole
Oceanographic Institute launched Alvin, a 2 m (7
ft) titanium sphere able to hold a pilot and two
observers. Although it could not dive as deep as
its predecessor, it was far more mobile on
reaching the bottom. Alvin has become the
workhorse of deep sea exploration and has gone on
to discover the hot vents and explore the wreck
of the Titanic. It is still in active use today.
Alvin can reach a depth of about 4,500 m (14,764
ft) but even this amazing craft reaches less than
halfway to the bottom of the ocean.
32
10.1 PEOPLE AND THE OCEAN
5. MIR The MIR submersibles were designed and
built by the Russians and Finns. They can reach
a maximum depth of 6,000 m (19,680 ft) thus
giving them access to up to 98 of the world's
oceans. The MIR submersibles are two of only five
manned submersibles in the world that can dive
beyond 3,000m (9,840 feet). The pressure sphere
is constructed of special nickel-steel and is
designed to withstand the enormous pressures at
these ocean depths. The MIR submersibles have an
overall length of 7.8 m (25 ft) and their cabin
is 2.1 m (7 ft) in diameter, accommodating one
pilot and two passengers. 6. Trieste Trieste
II In 1948, Auguste Piccard suspended a 10 tonne
steel sphere from a gas-filled float. This
bathyscaphe was used to dive in the Atlantic and
Mediterranean as deep as 4,000 m (13,123 ft). In
1960, a second-generation Trieste, carried
Piccards son, Jacques and U.S. Navy diver Don
Walsh, to the bottom of the Challenger Deep 11
km (7 miles) deep in the Marianas Trench. They
remain the only people to have reached this
deepest spot in the ocean.
Interesting! Numerous worldwide expeditions have been conducted with the MIR submersibles. The discovery of hydrothermal vent life on the ocean floor was one of the greatest discoveries of the 20th century. The MIR submersibles have visited 12 of these hydrothermal vent sites both in the Pacific and Atlantic Ocean. Three of these sites were visited for the first time ever by the MIR's. Other voyages include the Titanic and German battleship Bismarck. In 1989, MIR submersibles undertook observations and encapsulation of the Russian nuclear submarine Komsomolets sunk in the Norwegian Sea in 1,700 m (5,576 ft) of water. Work was also carried out on the wreck of the Russian submarine Kursk in the Barents Sea in 2000 and the Japanese submarine I-52 located in the Atlantic Ocean.
33
10.1 PEOPLE AND THE OCEAN
REMOTE OPERATED VEHICLES (ROVs) Manned deep sea
exploration is dangerous because the great
pressures can crush submersibles. As a result,
there has been increased use of un-manned remote
operated vehicles. Some people believe that
remotely operated vehicles carrying cameras and a
battery of sensors are a much safer and more
efficient way to study the deep sea, while others
feel that real-life viewing is essential.
REFERENCES FURTHER READING http//www.nationalge
ographic.com/k19/disasters_detail2.html -
Submarine maximum depth http//www.wisegeek.com/wh
at-is-the-deepest-depth-a-submarine-can-go.htm htt
p//www.fas.org/man/dod-101/sys/ship/deep.htm -
Submarine maximum depth http//www.deepoceanexpedi
tions.com MIR http//news.bbc.co.uk/2/hi/europe/
7530230.stm MIR dive to Lake
Baikal http//www.pbs.org/wnet/savageseas/deep-sid
e-journey.html Trieste
34
10.1 PEOPLE AND THE OCEAN
35
10.1 PEOPLE AND THE OCEAN
10.1.3 Bathysphere HISTORY Our first view of the
deep sea was probably through the exploration
work of two individuals named Otis Barton and
William Beebe who used a bathysphere to film the
deep sea. To study the deep sea, the bathysphere
was hoisted by steel cable over the side of a
ship and lowered nearly half a mile down into the
ocean a testament to the pioneering spirit and
courage of these early explorers. The
bathysphere was originally designed and developed
by Otis Barton, a Columbia University engineer,
while William Beebe (1877-1962) was a naturalist
with the New York Zoological Society. In the
late 1920s and 1930s, these pioneers set early
deep diving records (923 m (3,028 ft) in August,
1934) and observed denizens of the abyss that had
never been seen before. In many ways, they
introduced us to a new world and initiated an era
of oceanic research and deep-sea exploration that
continues to this day. Today, the New York
Zoological Society is known as the Wildlife
Conservation Society (WCS). The WCS manages the
New York urban wildlife parks (zoos and aquarium)
among other functions and Beebe is regarded as
one of its founding fathers. The original
bathysphere used by Beebe and Barton can be seen
at the New York Aquarium.
36
10.1 PEOPLE AND THE OCEAN
FEATURES The bathysphere is a hollow, steel ball,
with thick walls constructed to withstand the
enormous pressures exerted upon it at great
depths. The bathysphere is tethered to a hoist
by a steel cable and solid rubber hose which
carries electric wires that provide light and
communications to the divers. The front of the
bathysphere has three port holes with small,
thick glass windows for observation. In the
back, a steel cover plate is ordinarily bolted
over the entry port, sealing the divers and their
equipment within. Today, a perspex plate is
bolted over the port, which allows people to see
into the internal space, while protecting it from
litter and debris. The bathysphere is just 145
cm (57 in) in diameter and is cramped when two
men, a light, telephone, oxygen tanks, chemicals
(soda lime to absorb carbon dioxide and calcium
chloride to absorb moisture) and air-circulation
fans are packed within it. REFERENCES FURTHER
READING http//www.pbs.org/wgbh/amex/ice/sfeature/
beebe.html http//web.mit.edu/invent/iow/barton.ht
ml http//www.nyaquarium.org
37
10.1 PEOPLE AND THE OCEAN
10.1.4 Studying The Ocean 1. WHY STUDY THE
OCEAN? Understanding the ocean is more than a
matter of curiosity. Exploration, inquiry and
study are required to better understand ocean
systems and processes. Over the last 40 years,
the use of ocean resources such as oil, natural
gas, minerals, food, water and oxygen, has
increased significantly. The future
sustainability of ocean resources depends on our
understanding of those resources and their
potential and limitations. 2. NEW
TECHNOLOGIES New technologies, sensors and tools
are expanding our ability to explore the ocean.
Ocean scientists are relying more and more on
satellites, drifters, buoys, sub-sea
observatories and unmanned submersibles. (a)
Ocean Instrumentation Buoys Sensory instruments
that measure ocean conditions (e.g. air sea
temperature, wind speed direction, barometric
pressure, ultraviolet radiation, salinity, etc.)
are placed in many parts of the worlds oceans.
These instruments monitor conditions and transmit
data to satellites.
Ocean Literacy Principle 7(b) Understanding the ocean is more than a matter of curiosity. Exploration, inquiry and study are required to better understand ocean systems and processes.
Ocean Literacy Principle 7(c) Over the last 40 years, use of ocean resources has increased significantly therefore the future sustainability of ocean resources depends on our understanding of those resources and their potential and limitations.
Ocean Literacy Principle 7(d) New technologies, sensors and tools are expanding our ability to explore the ocean. Ocean scientists are relying more and more on satellites, drifters, buoys, subsea observatories and unmanned submersibles.
38
10.1 PEOPLE AND THE OCEAN
(b) Satellites Satellites can receive information
from Earth-based sensors and transmit the data
back to laboratories, research and meteorological
stations around the world for further analysis
and study. Satellites can also keep track of
surface temperature, currents and other changing
features of the oceans surface. They can also
take high resolution photographs of the ocean
surface. Since the 1970s, remote sensing from
satellites has become an increasingly important
and valuable tool for studying the oceans. (c)
Computers Modeling Many ocean processes are
extremely complex. In order to help us
understand these processes, mathematical models
are used to simplify the problem. Use of
mathematical models is now an essential part of
ocean sciences. They help us understand the
complexity of the ocean and of its interaction
with Earths climate. They process observations
and help describe the interactions among systems.
Raw data is initially gathered by sensors and
transmitted via satellite to computer systems.
Models are then run on these computer systems to
analyze the data and calculate results. Models
are also applied to predict events.
Ocean Literacy Principle 7(e) Use of mathematical models is now an essential part of ocean sciences. Models help us understand the complexity of the ocean and of its interaction with Earths climate. They process observations and help describe the interactions among systems.
39
10.1 PEOPLE AND THE OCEAN
3. NEW FIELDS Ocean exploration is truly
interdisciplinary. It requires new ways of
thinking and close collaboration among people in
a variety of fields including (a) Biology A
biologist is a scientist devoted to and producing
results in biology through the study of
organisms. They study organisms and their
relationship to their environment or carry out
research to discover the underlying mechanisms
that govern how organisms work. (b)
Geology Geology is the study of the solid earth,
its rocks and minerals. Geologists understand
how the dynamic forces which shape our earth work
and use this knowledge to predict their effect on
humans. Geologists are the field hands of
earth science. Without ground-based observations
to confirm information obtained from space-based
tools, we would have an incomplete or inaccurate
picture of our planet.
Ocean Literacy Principle 7(f) Ocean exploration is truly interdisciplinary. It requires close collaboration among biologists, chemists, climatologists, computer programmers, engineers, geologists, meteorologists, and physicists, and new ways of thinking
40
10.1 PEOPLE AND THE OCEAN
c) Oceanography An oceanographer is a scientist
who studies the physical and biological aspects
of the Earths oceans and seas. Oceanography
covers a wide range of topics including marine
organisms and ecosystem dynamics, ocean currents,
waves and geophysical fluid dynamics, plate
tectonics and the geology of the sea floor, and
fluxes of various chemical substances and
physical properties within the ocean and across
its boundaries. These diverse topics reflect
multiple disciplines (including biology,
chemistry, geology, meteorology, and physics)
that oceanographers blend to further knowledge of
the ocean and our understanding of processes
within it. (d) Chemistry Chemists study the
composition of matter and its small-scale
properties, such as density and acidity, and
describe the properties they study at molecular
level. Chemists measure substance proportions,
reaction rates and other chemical properties and
use this knowledge to learn the composition,
structure, chemical reactivity, and properties of
unfamiliar substances, as well as to reproduce
and synthesize large quantities of useful
naturally occurring substances and create new
artificial substances and processes.
41
10.1 PEOPLE AND THE OCEAN
(e) Climatology Climatology is the study of
climate (weather conditions over a period of
time). Phenomena of interest include the
atmospheric boundary layer, circulation patterns,
heat transfer, interactions between the
atmosphere and the oceans and land surface, and
the chemical and physical composition of the
atmosphere. (f) Computer Science Computer
programmers are able to write the sets of
instructions that tell computers the tasks the
computer is to perform. Many disciplines require
computers to carry out a wide range of tasks from
simple calculations to detailed data analysis and
statistics, to imaging and complex modeling
tasks. (g) Engineering Engineers use technology,
mathematics, and scientific knowledge to solve
practical problems. Engineers apply established
principles drawn from mathematics and science in
order to develop economical solutions to
technical problems. Engineers use computers
extensively for the analysis and production of
designs, the simulation and testing of the
operation of a machine, structure or system, and
the generation of part specifications. Many
engineers also use computers to monitor product
quality and control process efficiency.
42
10.1 PEOPLE AND THE OCEAN
(h) Meteorology A person who studies the earth's
atmosphere, especially in connection with weather
forecasting and weather-forming processes. (i)
Physics A physicist is a scientist who studies
the properties and interactions of matter and
energy in all their forms (liquid, solid, gas,
and plasma).
REFERENCES FURTHER READING http//en.wikipedia.o
rg/wiki/Biologist - Biologists http//en.wikipedia
.org/wiki/Chemist - Chemists http//en.wikipedia.o
rg/wiki/Climatologist - Climatologist http//en.wi
kipedia.org/wiki/Engineer - Engineer http//kids.e
arth.nasa.gov/archive/career/geologist.html -
Geologists http//www.mdbc.gov.au/subs/The_River/g
lossary.html - Meteorologists http//en.wikipedia.
org/wiki/Oceanographer - Oceanographer http//scif
iles.larc.nasa.gov/text/kids/Problem_Board/problem
s/light/glossary.html - Physicist http//www.coral
.noaa.gov/crews/ - NOAA Integrated Coral
Observing Network (ICON)
43
10.2 CONSERVATION
10.2 CONSERVATION
44
10.2 CONSERVATION
10.2 CONSERVATION 10.2.1 Why We Need The
Ocean The ocean affects all human life. It
supplies freshwater (most rainwater comes from
the ocean) and nearly all Earths oxygen. The
ocean moderates the Earths climate, influences
our weather, and affects human health. From the
ocean we get foods, medicines, and mineral and
energy resources. In addition, it provides jobs,
supports our nations economy, serves as a
highway for transportation of goods and people,
and plays a role in national security. The ocean
is a source of inspiration, recreation,
rejuvenation and discovery. It is also an
important element in the heritage of many
cultures. 1. Water The ocean is responsible for
supplies most of the worlds freshwater with most
rain originating from the ocean. Without
freshwater, most animal life would not exist. 2.
Oxygen Photosynthetic organisms in the ocean,
such as blue-green bacteria, phytoplankton, algae
and plants, supply nearly all Earths oxygen.
Without them, most animal life would not exist.
Ocean Literacy Principle 6(a) The ocean affects all human life. It supplies freshwater (most rain comes from the ocean) and nearly all Earths oxygen. It moderates the Earths climate, influences our weather, and affects human health.
Ocean Literacy Principle 6(b) From the ocean we get foods, medicines, and mineral and energy resources. In addition, it provides jobs, supports our nations economy, serves as a highway for transportation of goods and people, and plays a role in national security.
Ocean Literacy Principle 6(c) The ocean is a source of inspiration, recreation, rejuvenation and discovery. It is also an important element in the heritage of many cultures.
45
10.2 CONSERVATION
3. Climate Weather Both the Earths climate and
weather is driven by the ocean. 4. Food The
ocean provides us with food. For example, fish
provide much of the worlds protein food supply.
Every year about 75 million tons of fish are
caught. Mackerel, pollack, herring and tuna are
important pelagic (open ocean) fish while popular
demersal (bottom-living) fish include cod,
flounder, plaice, haddock, and crustaceans such
as crabs, lobsters and shrimp. 5. Medicines The
ocean also provides us with medicines. For
example, substantial research is focused upon the
use of coral reefs and reef organisms in the
development of new drugs to treat cancer,
Alzheimer's and other diseases. Like
rainforests, coral reefs also have enormous
potential for new medicines yet to be discovered.
Horseshoe crabs have several uses in medicine.
An extract of horseshoe crab blood Limulus
amoebocyte lysate (LAL) is used to ensure
biomedical products (e.g. vaccines) are free of
bacterial contamination. Horseshoe crab chitin
is used in manufacturing chitin-coated suturing
filament and wound dressing for burn victims.
46
10.2 CONSERVATION
6. Natural Energy Resources Minerals Seawater
and the sea floor are rich in mineral deposits
and other natural energy resources (e.g. oil,
gas). People have extracted salt from seawater
for thousands of years. In hot countries,
saltwater is pumped into shallow pools and
allowed to evaporate. The salt left behind can
then be collected. In cold climates, workers
separate salt by boiling seawater. Other
important elements separated from seawater
include bromine and magnesium. Offshore sea-beds
are a source of building materials such as shells
for making cement, sand and gravel. This is
sucked up by powerful pumps into barges for
transportation. Worldwide, offshore dredging
produces about 1.2 billion tons of sand and
gravel a year mainly for concrete manufacture.
Other minerals include iron, tin, and manganese
which are widely needed in industry. Much of the
worlds oil and gas supply is now piped up from
under the floors of shallow seas fringing the
continents. Semi-submersible platforms floating
in water 300 m (1,000 ft) deep can test drill
through 9,000 m (29,500 ft) of sea-bed rock.
Steel or concrete production platforms weighing
up to 30,000 tons stand in 900 m (3,000 ft) of
water.
47
10.2 CONSERVATION
7. Jobs Economy Working with the ocean means
that people have many different types of jobs
ranging from fishermen to researchers. The ocean
may also be an important source of income for
local people from tourism and eco-tourism. In
some countries, the countrys economic health is
dependent upon the ocean. 8. Transportation
National Security The ocean serves as a highway
for transportation of goods and people, and plays
a role in national security. Oceans or seas also
protect nations. For example, one reason the
U.K. has not been successfully invaded since 1066
AD is due at least in part to its geographical
separation from the rest of Europe by the
Channel. More subtly, the ocean also protects
nations and native species from invasive species
and diseases. 9. Recreation The ocean is also a
source of inspiration, recreation, rejuvenation
and discovery for many people. It is also an
important element in the heritage of many
cultures. For example, tropical beaches and
coral reefs provide a place for recreational
activities, such as swimming, snorkeling, and
scuba diving. Other activities include fishing,
boating, surfing and other water sports.
Interesting! Lionfish are not native to the North Atlantic or Caribbean but they can now be found in Florida, Bahamas and Cayman Islands. It seems that several lionfish, which are popular in home aquaria, were accidentally released while they were being transported from their native Indian and Pacific Ocean home and they were able to invade and successfully colonize a new ocean.
48
10.2 CONSERVATION
10.2.2 Problems Humans affect the ocean in a
variety of ways. Laws, regulations and resource
management affect what is taken out and put into
the ocean. Human development and activity leads
to pollution (point source, non-point source, and
noise pollution) and physical modifications
(changes to beaches, shores and rivers). In
addition, humans have removed most of the large
vertebrates from the ocean. The problems we
have fall into three main categories 1.
POLLUTION PUTTING HAZARDOUS MATERIALS INTO THE
OCEAN Pollution" is the negative effect from
by-products of human civilization that change the
natural environment. Pollution can take almost
any form and there are many forms that can be
hazardous and unhealthy to life in the oceans
including (a) Sewage Improperly treated sewage
is one major contributor to pollution in the
oceans. When sewage flows into the ocean, it
causes nutrient loading. Nutrient loading
(eutrophication) is the presence of excess
nutrients in the water that plants use to grow
and survive. With coral reefs, for example,
excessive nutrients can cause algae blooms which
can cloud the water blocking the corals from
sunlight. Macro-algae can then very quickly
overgrow and smother corals.
Ocean Literacy Principle 6(e) Humans affect the ocean in a variety of ways. Laws, regulations and resource management affect what is taken out and put into the ocean. Human development and activity leads to pollution (point source, non-point source, and noise pollution) and physical modifications (changes to beaches, shores and rivers). In addition, humans have removed most of the large vertebrates from the ocean.
49
10.2 CONSERVATION
(b) Runoff Runoff from land can also cause
nutrient loading. Humans use fertilizers on
farms and lawns. When it rains, these fertilizers
are washed into the nearby rivers and streams and
eventually end up in the ocean. The same
fertilizers that will make lawns look lush and
beautiful will also cause algae blooms in the
ocean. Heavy metals, pesticides and many harmful
chemicals enter the ocean through runoff, all of
which can have harmful effects on ocean
life. (c) Warm Water Many industries create warm
water as a by-product. Power plants and
desalination plants, for example, both release
large quantities of warm water. Warmer water
temperatures can make coastal areas uninhabitable
for marine life. (d) Fresh Water Fresh water is
not something commonly thought of as a pollutant.
However, fresh water can be deadly to sea life.
For example, the water level in the Florida
Everglades is controlled by man-made gates. When
the gates are opened, a rush of fresh water is
released into the surrounding sea grass beds
which can cause the sea grass to die. Sea grass
beds act as fish and coral nurseries. When sea
grass beds die, this habitat is eliminated and
much of the sediment that was held by the sea
grass is loosened. The water becomes more turbid
which in turn, affects the Floridian coral reefs
nearby.
50
10.2 CONSERVATION
(e) Noise Ship engines, propellers and submarines
that utilize sonar make a lot of noise. This can
disrupt mating rituals in sea mammals such as
whales and cause distress. For humans who live
in big cities or who have had to endure a
pneumatic drill or loud noises for extended
periods of time will know how aggravating these
sounds can be and how much stress they can
engender. (f) Plastic Plastics are typically
chains of carbon atoms (polymers) with
elements, such as chlorine, added to it. Plastic
is strong, durable and lightweight. It is an
integral component to modern life and has
multiple uses that are critical to human welfare.
However, plastic is not biodegradable and cannot
easily be broken down and removed from the
environment. This has led to it becoming a very
serious pollutant.
Important! It is easy to blame plastic for some of the problems we have but one also must not forget the immense benefits plastics have brought us. Plastics have many important uses in modern life, including packaging to keep food fresh and medicines sterile. Plastics are also used in the fabrication of numerous technological tools and devices. Scientists are working on alternatives to plastics that are just as useful but are also biodegradable. At the moment, however, our main recourse is to reduce plastic usage and increase reuse as much as possible.
51
10.2 CONSERVATION
One area of the ocean which is particularly badly
polluted by plastic is the North Pacific Gyre.
The North Pacific Gyre is a swirling vortex of
ocean currents comprising most of the northern
Pacific Ocean. The North Pacific Gyre has a
clockwise circular pattern but is relatively
stationary at its center. The circular rotation
of the gyre draws in waste material which has led
to the accumulation of flotsam and other debris
in huge floating patches of waste which has led
to it being named the Great Pacific Garbage
Patch or the Pacific Trash Vortex. Some
sources have reported that this floating
continent of debris is more than 4,000 km (2,485
miles) wide. A second trash vortex has also
formed off the coast of Japan. While only half
the size of the one northeast of Hawaii, it is
still sizeable. Rather than biodegrade, plastic
disintegrates into smaller and smaller pieces and
can enter the ocean food chain. The small
particles resemble zooplankton, which can lead to
them being consumed by jellyfish and other
animals. Transparent plastic bags also resemble
jellyfish and sea turtles can mistake them for
food. Many types of plastic may end up in the
stomachs of marine birds. Eventually, these
animals die of starvation, their stomachs filled
with un-digestible plastic.
Interesting! In order to make plastics, we need a source of carbon. Frequently, this source is oil. Thus, oil is important not just as fuel for cars but also to make plastics. It is also why when you burn plastic, you get a large amount of noxious black smoke which comes from burning carbon.
52
10.2 CONSERVATION
2. PHYSICAL MODIFICATIONS CHANGING THE
OCEAN (a) Development Much of the worlds
population lives in coastal areas. As a result,
a great deal of development has been carried out
around the continental coasts. This has resulted
in many problems including the removal and/or
destruction of mangroves and turtle grass beds
which are important breeding grounds for young
sea life. It has already resulted in the removal
of many breeding grounds for sea turtles and sea
mammals. (b) Erosion Coastal regions are
susceptible to erosion and natural hazards (e.g.
tsunamis, hurricanes, cyclones, sea level change,
and storm surges) which are ordinarily buffered
by sand on beaches. However, dredging and the
removal of mangroves and sea grass beds has
increased the level of erosion.
Ocean Literacy Principle 6(d) Much of the worlds population lives in coastal areas.
Ocean Literacy Principle 6(f) Coastal regions are susceptible to natural hazards (tsunamis, hurricanes, cyclones, sea level change, and storm surges).
53
10.2 CONSERVATION
3. OVER-EXPLOITATION EXTRACTING TOO MUCH FROM
THE OCEAN (a) Over-Fishing Modern fishing
techniques are extraordinarily efficient.
Unfortunately, this is not necessarily a good
thing. Their very efficiency means that we take
huge amounts of fish from the ocean. Inshore,
nets are thrown and traps set by hand to catch
fish, crabs and octopuses. Out at sea, sonar
devices help fishing boats track down large
shoals and special nets or hooks catch fish
living at different depths. Trawlers hunt
demersal species by dragging trawl nets over the
sea-bed. Purse seine nets are pulled shut to
trap mid-water species. Pelagic fish are either
snared on long curtain-like drift nets hung from
buoys or caught on hooks attached to long lines.
Small craft may supply one big factory ship,
where fish are gutted, frozen and stored for
several weeks. In one day, a single factory ship
can process more than 600 tons of fish. Methods
such as these mean that we have dramatically
reduced the stock of many species. For example,
there is huge concern that we have over-fished
parts of the North Atlantic. Farming of certain
species, such as salmon, may help alleviate this
problem but fish farms may have their own
environmental consequences.
54
10.2 CONSERVATION
(b) Wasteful Practices Unfortunately, it is not
just the fact that we take an enormous number of
fish from the ocean every year but also the
manner in which we take these fish which, in
extreme cases, can be considered criminally
wasteful. For example, tens of thousands of
sharks, wahoo and dorado are often caught as a
by-catch of tuna fishing and simply discarded as
waste. Another wasteful and brutal practice
which, thankfully, is being stopped is finning.
Here, shark fins, which are used in making soup
and Eastern medicine, are cut off the shark while
the rest of the shark is simply thrown back into
the ocean to die.
REFERENCES FURTHER READING http//www.americanch
emistry.com/s_plastics/sec_learning.asp?CID1571D
ID5957 - Plastic http//en.wikipedia.org/wiki/Pla
stic - Plastic http//www.cbsnews.com/stories/2004
/01/06/eveningnews/main591770.shtml - North
Pacific Gyre http//www.naturalhistorymag.com/1103
/1103_feature.html - Trash and the North Pacific
Gyre http//oceans.greenpeace.org/en/the-expeditio
n/news/trashing-our-oceans/ocean_pollution_animati
on - North Pacific Gyre http//www7.nationalgeogra
phic.com/ngm/0704/feature1/index.html Fish
Crisis 1 http//www7.nationalgeographic.com/ngm/07
04/feature2/index.html Fish Crisis
2 http//www7.nationalgeographic.com/ngm/0704/feat
ure3/index.html Fish Crisis 3 http//news.bbc.co
.uk/2/hi/science/nature/7314240.stm - New battle
of Midway over plastic http//news.bbc.co.uk/2/hi
/science/nature/7316441.stm - Warning on
plastics toxic threat http//news.bbc.co.uk/2/hi/
science/nature/7312777.stm - Dairy from the
middle of nowhere
55
10.2 CONSERVATION
  • 10.2.3 Better News
  • Fortunately, it is not all bad news. Many
    governments are now aware of the need to protect
    coasts and offshore waters from pollution and
    damage, and are taking steps to both clean up the
    environment and prevent further damage. Cleanup
    for oil spills, for example, include
    oil-dispersing chemicals and floating booms that
    help prevent oil spreading into narrow bays.
    Other examples of encouraging efforts include
  • In 1976, Mediterranean countries agreed on an
    action plan to prevent sewage and chemicals from
    flowing into the Mediterranean.
  • Asian countries have begun to conserve mangrove
    forests and over 60 countries now protect reefs
    to some degree.
  • Engineers are also discovering ways to save
    coasts from erosion. In some places, they have
    found that soft sea defenses (artificial beaches)
    are better than hard ones (concrete walls) at
    protecting shores from wave erosion. For
    example, waves along the Florida coast were
    gradually eating into the shore, threatening to
    wash away Miamis waterside hotels. Vacationers
    can now enjoy 25 km (15 miles) of artificial
    beach created from imported sand. By preventing
    erosion, this beach restoration proj
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